Mazda Rotary Club

So I wanted to start an Interesting thread.

With a plethora of power and rwhp claims n :censored::censored::censored::censored: abound I had a top brilliant idea and that is the standardize the out put down to N/A terms for a few common engines and many people could apply it to their own? and build a up a data base here.

So here is how it follows.

1 atmosphere roughly = 1 bar absolute, so whatever your boost pressure is (psi, bar, kg/cm, horse forskins!) convert it to absolute bar (ambient + your gauge boost pressure) then divide your ENGINE POWER by this. I\'ll illustrate by a few examples of mine.

When you go through and work out how much power your engine set up makes N/A then it is easy to work out how much boost you need to make some big power, fit the right turbo and cooler to keep charge temp under control and other mapping basics this is what you theoretically will get......

eg: ~250bhp 13B N/A on 43psi boost (what will it make?)
(43/14.5) = 2.965
2.965 + 1 = 3.965 absolute pressure
250 x 3.965 = 991.4 bhp!
NOTE: F1 mid 80\'s 5.6bar boost absolute (66.7psi gauge boost) would yield ~1400bhp interestingly EXACTLY what a 1.5lt stock block BMW road car engine did @ 10200rpm :)

Some 13B engine combos worked out for base power N/A (post up yours) you will need to estimate your engine power! NOTE: dynapack chassis dyno users I have used a figure of 1.15 multiplier on FD platform and this is commonly accepted across the traps who use this type to guess the engine power, its pretty close! > http://translate.google.com.au/translate?hl=en&sl=ja&u=http://www.famspeed.co.jp/mnt/power/index.html&ei=lK6BTeeEJ4mYvAPrpOzICA&sa=X&oi=translate&ct=result&resnum=8&ved=0CFkQ7gEwBw&prev=/search%3Fq%3Dfamspeed%2B13B%26hl%3Den%26safe%3Doff%26client%3Dfirefox-a%26hs%3DMBn%26sa%3DG%26rls%3Dorg.mozilla:en-US:official%26prmd%3Divnsfd


13B-REW (stock standard)
T04Z 1.32 A/R & stock twin turbo\'s tested (on exact same set up)
3.5" exhaust dual muffler (quiet)
9.0:1 compression ratio 45 deg C charge temp (for both set ups) 29psi v\'s 13psi *water sprayed IC and water injection internally on single turbo*
365bhp @ 6700rpm engine power @ 13psi boost twins, same exhaust, IC, intake etc SP specification.
565bhp @ 6700rpm engine power @ 29psi boost Single Turbo, water spray IC, and RR water injection
(29/14.5) = 2.0
2.0 + 1 = 3.0 bar absolute pressure
565bhp / 3.0 = 188bhp
So a stock block 100% stock ported 13B-REW will give 188bhp @ the engine N/A *2.0bar boost*
So a stock block 100% stock ported 13B-REW will give 192bhp @ the engine N/A *0.9bar boost*

FAMSPEED 13B-REW
The new high-flow turbine test (More FAMSPEED RESULTS) confirming my testing on stock ported 13B-REW
ブースト：1.1ｋ Boost: 1.1k 　 トルク：45.2kg/5907rpm 馬力：408.0ps/6692rpm 408.0ps/6692rpm: hp 45.2kg/5907rpm: torque
　 ↓ 10.6%アップ ↓ 10.6% up
ブースト：1.3ｋ Boost: 1.3k 　 トルク：51.1kg/5386rpm 馬力：451.3ps/6697rpm 451.3ps/6697rpm: hp 51.1kg/5386rpm: torque
↓ 4.3%アップ（ブーストタレの為） ↓ (for boost sagging) up 4.3%
ブースト：1.5ｋ Boost: 1.5k 　 トルク：53.5kg/5689rpm 馬力：470.8ps/6664rpm 470.8ps/6664rpm: hp 53.5kg/5689rpm: torque
^^^FAMspeed RX7 13B-REW "tickled up" stock port ports just polished no real timing change "modified twins"
various power levels listed at 6700rpm maximum peak (TCF 1.15) high flow twins
Works out to 194bhp *1.1bar boost* 188bhp *1.5bar boost* @ engine N/A

13B-S5 (mild street ported)
actual engine dyno tested @ 7500rpm
3" exhaust 1 muffler
and fitted with T66 1.00 A/R
9.0:1 compression ratio 1.7bar boost pressure with 2.1 bar exhaust manifold pressure
580.1bhp @ 7500rpm engine power @ ~25psi boost RR water injection
(1.7 bar) = 1.7bar
1.7 + 1 = 2.7 bar absolute pressure
580.1 / 2.7 = 215bhp
So a mild street port 13B-S5 block makes 215bhp @ the engine N/A

13B-S5 or 13B-COSMO (RR street ported)
both deliver peak power @ 7600rpm
3" exhaust 1 muffler
and either fitted with T04 1.32 A/R or T51 deliver following
9.0:1 compression ratio 45 deg C charge temp
549.7bhp @ 7600rpm engine power @ 18.3psi boost S5 variant with T04 RR water injection
633.5bhp @ 7600rpm engine power @ 24psi boost COSMO variant with T51 RR water injection
S5 worked out below
(18.3/14.5) = 1.262
1.24 + 1 = 2.262 bar absolute pressure
550 / 2.262 = 243bhp
So a RR street port 13B-Cosmo or S5 block makes 240bhp to 243bhp @ the engine N/A

SCOOT RX7 "top speed car" 13B-REW Peripheral port "cross port motor"
710bhp on 29psi boost @ 7100rpm (dyno print out on coast down converts to estimated engine power *can provide data*)
HKS T51KAI 1.0A/R
Works out to 236bhp @ engine N/A
and on ~1.48bar boost (610bhp)
Works out to 245bhp @ engine N/A

PANspeed RX7 13B-REW Bridge port
578.5bhp on 18.5psi boost (~1.30 bar) @ 7800rpm (TCF 1.00 shown > 503.1rearhubhp)
HKS T04Z 1.0A/R
Works out to 251bhp @ engine N/A

FAMspeed RX7 13B-REW Peripheral port "cross port motor"
646bhp on 21psi boost (1.45 bar) @ 6700rpm (TCF 1.15 so it actually made 561.7rearhubhp)
HKS T51SPL 1.0A/R
Works out to 258bhp @ engine N/A

Racing Beat 13B circa 1986 (Twin Turbo Bridge Port)
530bhp on 15psi boost @ 8000rpm
3" x 2 open pipes :censored::censored::censored::censored: OFF EAR BLEEDING LOUD!
5 deg C charge temp ICE/Alcohol cooler offset low engine compression ratio
(15/14.7) = 1.03
1.03 + 1 = 2.03bar absolute pressure
530 / 2.03 = 261bhp
Racing Beat bridge port 7.5:1 comp engine made 261bhp @ engine N/A

FULL Bridge Port 13B-Cosmo N/A style primary and secondary
3.5" exhaust 1 muffler *loud*
660bhp on 21psi boost @ 8500rpm 9.0:1 compression ratio RR water injection
Garrett T51 1.22A/R
(21/14.50) = 1.448
1 + 1.448 = 2.448 absolute pressure
660/2.448 = 269bhp
Works out to 269bhp @ engine N/A
Same engine fitted with 7.8:1 compression rotors gave below reading
690bhp on 24psi boost RR water injection
Works out to 260bhp @ engine N/A



RR street port V\'s stock ports

(http://www.riceracing.com.au/Hoon%20build%206.JPG) (http://img170.imageshack.us/img170/3606/hoon18fx6.jpg)

(http://img171.imageshack.us/img171/5426/hoon17bj7.jpg) (http://img240.imageshack.us/img240/8396/hoon11ax0.jpg)

(http://img443.imageshack.us/img443/3032/hoonexhaust3ai5.jpg)

In summary, if your system is efficient and the block can take it! then for each 1 bar increase in absolute pressure or each extra atmosphere you will make 100% more power.

250bhp N/A on 5.6 bar absolute boost pressure = 1400bhp
1400bhp - 250 bhp N/A = 1150bhp increase due to boost pressure
1150bhp/250bhp = 4.6 x 100 = 460% increase in power! simple.
Therefor each 1 bar over N/A = 100% power increase as there is 100% more air, assuming you keep charge temps under control the motor was not built by BDC ;)

As a historical context in 1986 when BMW managed regularly to get 1400bhp in qualifying from their stock block 4cyl 1.5 motors they were pumping 6 lt of water per lap onto the after cooler to keep charge temperature at the normal level of 45 deg C! so their power output followed this linear scale quite well as it did on the dyno when they tested it, you will need to compressor map width and turbine to match before you think of doing :censored::censored::censored::censored: like this, but its been done before in the rotary world.

Typically on a 2 rotor full bridge port engine a GT45R is needed to support 36 psi gauge pressures and keep the relationship in tact, delivering around 825rwhp or so on cars I have worked with. For the higher pressure ratio\'s in Garret Nomenclature you are then looking at GT47 sized units or hybrids to do this.

But for most people who are normal this is interesting to see your power to boost and if your set up is efficient or if you are wondering what you can do with your bits you have. There should be lots of honest 500 to 600bhp cars around, then again lol

Quote from: Mitchocalypse;223393Hmm. I\'ve often thought about this exact concept and would have applied it exactly the same as you have but the more and more I thought about it, the more i found things that might throw off the approximation so I pretty much just dismissed the idea.

Have you tested how accurate this is? Maybe it\'s just the way i\'m looking at it but it almost seems over simplistic. I\'m sure it gives a reasonable approximation -  but how accurate is my question?

The two biggest things for me are intake air temp and volumetric efficiency. Obviously i don\'t need to explain the fundamental gas law, but I was also under the impression that at higher rpms, internal combustion engines (n/a) could reach greater than 100% volumetric efficiency so the absolute pressure in the manifold (or combustion chamber) could be greater than 1 bar absolute.

The way I\'m looking at it (and I know I\'m missing some things) is that doubling the absolute pressure wouldn\'t actually double the power.

Sure it\'s a good approximation, but how good?

It\'s 100%

So long as you have the compressor map width and turbine to match i.e. BIGGER TURBO *to match your pressure ratio target, thus power target* (efficiency) and charge cooler big enough for the extra heat rejection. I have proven it in my own testing and that with rotary turbo drag cars I consult on. And its been proven over and over in many piston turbo examples most notable F1 1000bhp era.

Volumetric efficiency of stock ports is around 85%
My Street Ports around 105%
Bridge and Peripheral (many variations!) but say 110% (as used in turbo applications).
NOTE: Power differences are not just a function of this but where the power is made

The match between turbine to compressor (again I test this and have posted up many graphs not Howard Coleman like conjecture and personal theory) is so long as relationships are maintained PORTS are not the restriction never ever have been to ultimate power, all they define is where it is made due to charging efficiency at higher engine speeds.

(Turbo\'s are simple as stated. And ancillaries as well, if you are reading this thread and comprehend it so far you will be all over these basics too.)

The formula and how it works is proven ;)

So the base engine (aside from mechanical strength!) was and is never the issue, its the bolt ons and adaption of water injection or aftercooling spraying to keep charge temperature under control and so long as you have the appropriate turbo its a prefect linear relationship.

It is and can be swayed by these variables:

* If you are greatly reducing ign timing as boost increase
* If you are making vast changes to AFR as boost increase

Then you can have non linear discrepancies of over 25%!!!
But if you run water injected especially these boundary restrictions do not apply ;)

To give you a practical proven example a BMW F1 turbo mapped on an engine dyno here (I have the dyno sheet!) is Australia did 802bhp @ 3.3bar with lambda of 0.79 @ 10,000rpm and at 5.6bar uses the same lambda and water spraying the IC it see\'s over 1350bhp That was the going rate at the time for the qualifying power output at that boost pressure ;)

Quote from: Mitchocalypse;223441Well I\'ll be darned :willy_nilly:

I gotta say, the thing I like the most about your posts is that you explain the theoretical side of things and then follow it up with an example that agrees with what the textbook says.

Thanks ;)

That is how I teach (It\'s my profession) :) it adds credibility and separates the wannabe\'s from the ones who actually have done it ;)

I like many others get sick and tired in forum world of reading crack pot theories or regurgitated information by overnight wonders who have never done anything of the sort. My idea is to understand the theory and then apply it myself, THEN talk about it. And back it up ........... odd concept I know to some lol.

You asked an excellent and insightful question before and I hope I explained it, back when I was doing tests on the standard ports and collecting data on everything I personally saw near a linear rise to the point where there was divergence between TIP and MIP (turbine inlet pressure and manifold inlet pressure) *read turbo becoming too small* so then I experimented with 1.00 to 1.15 and to finally 1.32 A/R turbine housings then to the point of the turbo itself being too small. So that is a critical point and lots of good engineering writing on the subject explains balance of gas flows between turbine to compressor. Second "mapping" considerations which lots dont talk about is excess fuel ratio\'s and spark timing, and tertiary considerations are the charge temperature and knock limitation of the fuel you use relative to the CR you choose to implement (inter related issues to a point).

But if all things are appropriate for the target goal then sky is the limit, so long as you do not exceed thermal capacity of critical engine components or mechanical strength, and it is advantageous to keep rpm low and vastly increase pressure as this is far far less stressful.

Wanted to keep it simple though, but hopefully this explains the "theory" is sound and proven in reality too :)

More engines added, this time Panspeed 13B-REW 9.0:1 compression ratio engine bridge ported with T04Z as run last year at World Time attack, tuned before shipping to event.

(http://img834.imageshack.us/img834/9040/panspeedrx713brewbridge.jpg)

I bet longevity is somewhat curtailed at this point though.  Back in the day it was castor based oils too?  Don\'t see too much of that these days.

Nice write up :)

my head hurts now..........

Takes some time to read it through. It makes sense. Lots of data to back up the theory too

I\'m amazed that the 7.5-1 comp rotors are making the third highest HP NA on that list??!! I didn\'t know you could get comp ratio that low? I thought the lowest was 8.5-1?

Does the theory apply across to 20Bs too?

This theory applies to just about any internal combustion engine.  It rings true with my experiences too, stock port RX8s make about 190 hp at the flywheel which is similar to the 13B-REW.

Quote from: Grant Monkhouse;846102I\'m amazed that the 7.5-1 comp rotors are making the third highest HP NA on that list??!! I didn\'t know you could get comp ratio that low? I thought the lowest was 8.5-1?

Does the theory apply across to 20Bs too?

Yes any engine as wil said.

The 7.5:1 are special factory Mazda racing parts.
The 7.8:1 are Rice Racing modified "hand balanced" S4 turbo versions that I pioneered a long time ago (proven in the Mazda Capella on my web page). You achieve that by porting out the combustion pockets to reduce the compression ratio.
Reducing the compression ratio effects power a little bit on boost to boost application but it makes the engine produce allot more power as its tolerant to much higher boost pressures, inlet charge temps, ignition timing, fuel quality etc etc....... brake specific fuel consumption leaves allot to be desired though! less work in compression stage = far worse fuel efficiency.

Bit off topic, but the main gist is the porting styles and working it back to a figure that can be easily compared

bmw used to leave their engine blocks outside and get the engineers to wee on them, any blocks that were still sound after that treatment were cleaned up and used for the F1 engines.

Good write up - would be good to get some other writeup\'s on what engines were a good build and which were not - in terms of longevity, wideness of poweer curve, etc.

Just been trying to work out the power gains drag car NA power.

They\'re making 771RWHP @ 1.8bar/26.1psi

26.1/14.5 = 1.8 + 1
771/2.8 = 275RWHP NA?!!

Now using the correction factor of 1.15 to get FWHP

771 x 1.15 = 886 FWHP

886/2.8 = 316FWHP NA!!

Now what would this engine make at 35psi??

35/14.5 = 2.4 + 1 = 3.4
316 x 3.4 = 1074FWHP

WOW, I hope I\'ve worked it out right.

One caveat is that you need to be 100% sure of a couple of things

1. Boost pressure (to record that power figure)
2. Conversion used to guess the engine power

The James car uses a custom intake manifold where as ALL of the cars I list except for the Racing Beat 1986 FC all predominantly still use the stock inlet manifolding, this has an effect for the peak power range. RPM = power and that car with a turbo the size used on an old F1 car lol and the inlet manifold could well mean its 20bhp to 30bhp more than all the ones listed here.

A bit of common sense though never ever goes astray.

There is the best NA bridge ports raced here in Australia in IPRA and the highest ever seen on an actual engine dyno delivers somewhere around 320bhp or so @ 9500rpm. Now remember this is with high compression rotors and ideal AFR in NA form (13.5:1) so typically as you will see any engine mimiking ultimate NA porting will never quite reach the ideal NA power range as its got fundamental tuning working against it as well as some other factors I will leave out as its a bit complex.

This is where VBOX testing or Trap speeds can be your friend :)

We have a few 28x9 cars that I consult on that do 165 to 170mph terminal at a higher weight than that car? so you can guess the power from that. Some of these cars will dyno out 670rwhp @ 28psi boost *say 2.0bar* (around 800bhp at best guess). So you can use the terminal speeds to good effect especially when you are looking at cars in the exact same chassis "untubbed rear tire" and fitted with a dog box etc etc.

There is no real magic here except that you need to be 100% honest with the figures, and when you are you will see that the numbers all neatly match quite well :)

p.s. If it sounds too good to be true then typically it is ;)
But ~300bhp I have seen on some cars in turbo form, running full BP, 10,000rpm capable inlet manifolds, higher compression ratio\'s running exotic fuels.

James is running racing fuel too. I don\'t think they\'re running WI though. They have run the car up to 35 psi but the dyno :censored::censored::censored::censored: itself. So it would be good to see if they got a reading and the figures match through +/- 10%.

It would be good if Jay could give the dyno session details etc. air temp and so on. 316FWHP NA is very high. Even 300 would be high.

The manifold they use is no doubt freeing up top end HP, but that\'s what they need

It\'s in the right ball park but it is relying on 15% powertrain losses.  If you went for 18% powertrain losses then it would be 324 HP.

To be honest, both those figures seem high for a Bridgeport 13B.  But I could be wrong on that.

Either way, the 160 mph terminal speed is exceptional.

Quote from: Grant Monkhouse;846128James is running racing fuel too. I don\'t think they\'re running WI though. They have run the car up to 35 psi but the dyno :censored::censored::censored::censored: itself. So it would be good to see if they got a reading and the figures match through +/- 10%.

It would be good if Jay could give the dyno session details etc. air temp and so on. 316FWHP NA is very high. Even 300 would be high.

The manifold they use is no doubt freeing up top end HP, but that\'s what they need

It\'s a nice set up for sure ;) Waste Gate out the bonnet is a bit extreme lol :burnout

:Thumbsup! More stuff we can add to the thread the better, though some probably don\'t want to share. Lots of the stuff I consult on I cant even dare to post here, but the thread is a good indicator, especially for road car set ups ;)

One thing to consider (most people forget) is that a well matched turbo system (especially when not maxed out) actually works with a positive pressure overlap. On my set up up to 4/5ths it maximum available power I actually had exhaust manifold pressure well under the inlet manifold pressure ! This is very beneficial especially when you are running higher overlap engine combination\'s ........ sadly not many people measure it and they just go about it hit and miss.

For a 13B BP set up you need a turbo as big as a house, typically GT47 or equivalent and when you use a big inlet manifold you don\'t get full boost in quick transient conditions till 7000rpm! or so (I\'ve seen this many times) loading it up in a higher gear it can be lower around 6k rpm, but that is just lying to yourself  (dont forget as boost goes up so does the rpm to reach it, so at 4 bar boost your not making it till 8000rpm in some cars I have seen with 13B\'s and well over 1000bhp!@):) totally not a streetable proposition at all :) unless you are a maniac hahaha.

Full boost by 7,000 rpm if you can rev the car out to 12,000rpm should give a good strong power band. Lol. Scary but good none the less.

I think people will share their HP figures but not necesarily the dyno sheet print outs. As we don\'t want to drop into that arguement yet again.

I think a good general rule is that on a ported motor, street or bridge, 1 bar of boost should give 500HP at the engine, divide that by 2 gives you 250hp NA. Prety good figure for an NA motor I think!

Apologies if you have all ready written that.

Rice, I am abit confused -Sorry. Can you please summarise and write something in a lay mans language. It\'s very hard to make sense out of things, especially, when you don\'t know the meaning of things you read whilst trying to understand a whole paragraph and or sentence.

To my understanding, you have never been a fan of porting and you always maintained that, rotary engine does not need porting? Am I getting it right?

Sorry If I am not getting it at all :(. Reading your posts are like reading a book of tuning. Loll

Keep up the good work mate

Mir

Quote from: Grant Monkhouse;846132Full boost by 7,000 rpm if you can rev the car out to 12,000rpm should give a good strong power band. Lol. Scary but good none the less.

I think people will share their HP figures but not necesarily the dyno sheet print outs. As we don\'t want to drop into that arguement yet again.

I think a good general rule is that on a ported motor, street or bridge, 1 bar of boost should give 500HP at the engine, divide that by 2 gives you 250hp NA. Prety good figure for an NA motor I think!

Apologies if you have all ready written that.

It is FAR less stressful on the motor bearings to increase BMEP than to increase engine rpm. Forces on the bearings increase 4 fold for a doubling of rpm, thus to make double power N/A @ 12000rpm you could make 4 times the power at the same 6000rpm simply by running more boost pressure or the same power on half the bearing loads!!!! due to far lower rpm. (hope that made sense?). Any combination between of BMEP loads (to do with boost pressure influencing combustion pressure) and rpm to reach the power target you want/need/dream about! *water injection is proven to yield a greater BMEP with less peak pressure stresses* side note. IE more power with less engien stress.

The same applies to the 13B-REW or Cosmo.

On stock set ups you will reach the rotor clearance limits using only 8000rpm and 32psi boost pressure (stock ports with T4 platform turbo) = around 600bhp, at this point the rotor sides crash! into the side plates! and not even the gay side step on the late model rotors addresses this! still not enough clearance. SO you 100% for long term use need to side clearance the rotors to have sustained high forces on the eccentric shaft and associated bending, otherwise your plates will be screwed and the rotors scored (I\'ll take pics).

So you get to the point where once the engine clearances are in check then the rotor bearings start crapping themselves, and again it is far less stressful to use more boost than it is excess long term rpm.

So it can be advantageous to keep the 13B-REW inlet manifold (Abel Ibara ran over 1000bhp on his 13B stock inlet manifold) before going 20B and making himself broke in the process! both in the R100 and RX7. Keep revs under 9000rpm and just keeping winding the boost pressure into it.

Lots more parts live and ironically if you match the compression ratio, or the fuel spec etc as needed its much more advanageous to increased engine life. :Typing

But to your point, def from the figures I posted above of "normal" set ups athat are durable as proven in track racing not just straigh line or dyno queens, then ~250bhp level is going to be a reliable figure to work with for sure for a bridge port set up (tuning being in the right window of course) :Talking1

Yeh I understand what you referring too. Rotation of any object is going to give the centre bearing/turning point more load. Easiest way I would think of it is the g force Increase. At 2 g it has the same mass but is exerting twice the force etc. I would dredd to think off the forces acting on a bearing at 10,000 rpm upwards!

All this sort of stuff makes me kind of gutted I became an electrician instead of an engineer as its far more interesting.

Quote from: Mir;846135Rice, I am abit confused -Sorry. Can you please summarise and write something in a lay mans language. It\'s very hard to make sense out of things, especially, when you don\'t know the meaning of things you read whilst trying to understand a whole paragraph and or sentence.

To my understanding, you have never been a fan of porting and you always maintained that, rotary engine does not need porting? Am I getting it right?

Sorry If I am not getting it at all :(. Reading your posts are like reading a book of tuning. Loll

Keep up the good work mate

Mir

Thanks.

Summary
For the street 13B-REW etc porting is not necessary at all. The engine will be far more responsive and have a wider power band on stock inlet manifold and stock intake porting. I have proven the power and durability of stock motor in my own car...... 4500rpm to 8000rpm you wont beat it hands down.
For racing, and road use, a good street port will match any bridge port (close enough) with none of the negative drawbacks associated with a "race port"
Street ports have merits, but you loose mid range power, just as you do with a bridge port, you mostly port the motor to "extend the range" IE give you more rpm, higher top speed for set gearing or to better match a close ratio gearbox, horse penis inlet manifold etc etc.

That is a general summary as I have seen it. Others can comment for sure and everyone will have their opinions on it :)
But porting always has negatives for the road. Do you need porting to make a fast car? no is the answer to that, god created turbo\'s to be used as he intended ................. boost it up !

:3gears-lh

I will add something interesting in this thread to help illustrate what I am saying about speed, power, road set ups v\'s track etc etc.

A little off topic but I\'m sure you will love this...........

So who has watched Hot Version Vol 107 yet? *you can youtube it*

Very interesting seeing all the tested weights, boost pressures, top speeds on back straight! and claimed power levels  :shock:

Excellent spread of cars and configurations  :wink:  Nice typo of the RE Amemiya car running a 4.3 rear diff when it has a 4.7 in it lol, but otherwise nice production.

RE Amemiya car
193.064kmh
twins @ 1.00kg/cm 402ps
1145kg

Famspeed
189kmh
twins @ 1.3kg/cm 499ps *where did the 100ps go?*
1153kg

R-Magic drift car
200.93kmh
T04Z 1.4kg/cm 580ps (sequential dog box)
1126kg

Domar spec drift
190.375kmh
T88 1.35kg/cm 570ps (sequential dog box)
1133kg

To pick the most exciting cars, interesting to see dyno dreams don\'t match with reality, very cool to watch the 5 lap race and see the 400ps twins car keep right up to the 580ps car! (within 1 car length along whole back straight up to 200kmh lol)........ guess who won?

Here is a list of very well known cars and their top speeds on the back straight at this track...
2007 17th Annual Revspeed Super Battle at Tsukuba Circuit

***NOTE*** ITS FUNNY HOW ~600PS Nissan\'s (M speed, Best Motorsports, Garage Ito) that weigh much more are 20+kmh faster lol (and that is with larger frontal area, higher drag too)!!!! I do have ALL of these cars on video along with detailed specs of the all as well ;)

    * 1st place- #13 M-Speed R34 Nissan Skyline GT-R (Best Lap: 55.23sec, Top Speed: 227.282 km/h)
    * 2nd place- #1 Garage HRS SUN Auto Cyber Evo CT9A Mitsubishi Lancer Evolution (Best Lap: 55.864sec, Top Speed: 220.678 km/h)
    * 3rd place- #22 Pro-Staff R Magic FD3S Mazda RX-7 (Best Lap: 55.947sec, Top Speed: 217.742 km/h)
    * 4th place- #12 Nagisa Auto R34 Nissan Skyline GT-R (Best Lap: 56.510sec, Top Speed: 227.082 km/h)
    * 5th place- #16 Kurumakobou Decide R33 Nissan Skyline GT-R (Best Lap: 56.630sec, Top Speed: 233.615 km/h)
    * 6th place- #14 Garage Kagotani R34 Nissan Skyline GT-R (Best Lap: 56.833sec, Top Speed: 227.416 km/h)
    * 7th place- #31 Autobacs ASM Honda S2000 (Best Lap: 57.398sec, Top Speed: 188.055 km/h)
    * 8th place- #18 Best Motor Sports R32 Nissan Skyline GT-R (Best Lap: 57.422sec, Top Speed: 220.994 km/h)
    * 9th place- #15 Hosaka Tuning Factory R33 Nissan Skyline GT-R (Best Lap: 57.504sec, Top Speed: 224.346 km/h)
    * 10th place- #17 Keiyo Jiko R32 Nissan Skyline GT-R (Best Lap: 57.658sec, Top Speed: N/A)
    * 11th place- #3 Jun Automechanics CT9A Mitsubishi Lancer Evolution (Best Lap: 57.824sec, Top Speed: 211.640 km/h)
    * 12th place- #19 Auto Gallery Yokohama R32 Nissan Skyline GT-R (Best Lap: 58.081sec, Top Speed: 223.8
    * 13th place- #21 Garage Ito R32 Nissan Skyline GT-R (Best Lap: 58.282sec, Top Speed: 216.650 km/h)
    * 14th place- #5 Varis CP9N Mitsubishi Lancer Evolution (Best Lap: 58.456sec, Top Speed: 211.102 km/h)
    * 15th place- #4 Stillway CT9A Mitsubishi Lancer Evolution (Best Lap: 58.484sec, Top Speed: 204.468 km/h)

If you look up that video and watch it you will graphically see the effect of power band and peak power offset to reality on a race up to 200kmh, you will see a peak top end power increase even when matted to a sequential dog box does not translate to a MASSIVE speed or distance increase pulled over what is a stock motor and stock trans set up only needing to change gear twice.

In my own car with this amplified even higher 565bhp v\'s 400bhp and retaining the same stock power band, it makes for a super fast in gear accelerating machine and that for the street is the best, and that is only achieved with stock intake ports and a low power peak of 6700rpm or so, which means you have a nice and FAT usable power range from 5k to 8k rpm.... that is what makes a road car fast, and even some race cars too ;)

Street ports are kind of the next step.

The idea of this thread is to balance as many of the variables out as is possible to make it easy for a layman to see, just look at the NA power level in RED. And what ever power goal you have in mind you can easy see the boost you will need to use to achieve it.

Ah enough typing for one day!!!

The 771 is a old dyno, we modified the bridge and exhaust ports and moved the power to the left by about 800 rpm. We could not get a peak reading as the dyno flat lined at about 7.5 to 8k from memory at 740 peak is over 9k remember these figures are at the HUBS, boost is 1.8 bar.
The car did at Surrey rolling road 580 at .8 bar and trapped 145 mph at this level.
The car weight is 2800ish with driver.
Have you got more details of the cars trapping 165 to 170 mph.
Interesting thread I will have a proper read later, just got to map a car!!!

Quote from: RICE RACING;846127One caveat is that you need to be 100% sure of a couple of things

1. Boost pressure (to record that power figure)
2. Conversion used to guess the engine power

The James car uses a custom intake manifold where as ALL of the cars I list except for the Racing Beat 1986 FC all predominantly still use the stock inlet manifolding, this has an effect for the peak power range. RPM = power and that car with a turbo the size used on an old F1 car lol and the inlet manifold could well mean its 20bhp to 30bhp more than all the ones listed here.

A bit of common sense though never ever goes astray.

There is the best NA bridge ports raced here in Australia in IPRA and the highest ever seen on an actual engine dyno delivers somewhere around 320bhp or so @ 9500rpm. Now remember this is with high compression rotors and ideal AFR in NA form (13.5:1) so typically as you will see any engine mimiking ultimate NA porting will never quite reach the ideal NA power range as its got fundamental tuning working against it as well as some other factors I will leave out as its a bit complex.

This is where VBOX testing or Trap speeds can be your friend :)

We have a few 28x9 cars that I consult on that do 165 to 170mph terminal at a higher weight than that car? so you can guess the power from that. Some of these cars will dyno out 670rwhp @ 28psi boost *say 2.0bar* (around 800bhp at best guess). So you can use the terminal speeds to good effect especially when you are looking at cars in the exact same chassis "untubbed rear tire" and fitted with a dog box etc etc.

There is no real magic here except that you need to be 100% honest with the figures, and when you are you will see that the numbers all neatly match quite well :)

p.s. If it sounds too good to be true then typically it is ;)
But ~300bhp I have seen on some cars in turbo form, running full BP, 10,000rpm capable inlet manifolds, higher compression ratio\'s running exotic fuels.

Didn\'t Abel have his intake extrude honed and also have the throttle body on a 90 degree bend, not sure if that was done for fitment issues or to increase volume of the intake, even though standard intake does not work that way.

Quote from: Grant Monkhouse;846102I\'m amazed that the 7.5-1 comp rotors are making the third highest HP NA on that list??!! I didn\'t know you could get comp ratio that low? I thought the lowest was 8.5-1?

Does the theory apply across to 20Bs too?

a 7.5 to 1 compression ratio rotor will not make the N/A power that you convert from turbo figures.
The thing to be taken into account with 7.5 to 1 compression is that there is more volume in the whole of the combustion chamber for more fuel and air so more power can be made from this under boost, especially higher boost levels where if you were running a higher compression rotor you would end up with less actual literal volume for the air and fuel to be able to fill.
So this means that the combustion volume is greater for this type of rotor and the turbo is what increases the compression ratio over what would occur naturally aspirated, so with these two things combined you can make more power than a normal compression rotor.

Quote from: HaywardRotary;846152a 7.5 to 1 compression ratio rotor will not make the N/A power that you convert from turbo figures.
The thing to be taken into account with 7.5 to 1 compression is that there is more volume in the whole of the combustion chamber for more fuel and air so more power can be made from this under boost, especially higher boost levels where if you were running a higher compression rotor you would end up with less actual literal volume for the air and fuel to be able to fill.
So this means that the combustion volume is greater for this type of rotor and the turbo is what increases the compression ratio over what would occur naturally aspirated, so with these two things combined you can make more power than a normal compression rotor.

Thanks Carl, it was/is the only one that didn\'t make sense to me throughout the table for power output/boost/compression ratio although on that specific setup they are running 5*C intake with an alcohol cooler so they have a lot more oxygen in that engine to start with as the others have much higher intake air temps.

Why don\'t a lot of turbo cars run lower compe rotors then? Are their not that many around or is it that the fd rotors are good even at 9.0-1 compression?

Can you remember which rotors you put in my engine? Iv forgot:(

What comp ratio are you going down to with your billet rotors Carl? :D

Quote from: HaywardRotary;846152a 7.5 to 1 compression ratio rotor will not make the N/A power that you convert from turbo figures.
The thing to be taken into account with 7.5 to 1 compression is that there is more volume in the whole of the combustion chamber for more fuel and air so more power can be made from this under boost, especially higher boost levels where if you were running a higher compression rotor you would end up with less actual literal volume for the air and fuel to be able to fill.
So this means that the combustion volume is greater for this type of rotor and the turbo is what increases the compression ratio over what would occur naturally aspirated, so with these two things combined you can make more power than a normal compression rotor.

^That is a common mistake most mechanics make.

*Your engine capacity does not change by changing the compression ratio mate* The volume does not change, its relationship between volume at TDC v\'s BDC, it is constant it never changes. It\'s a dead area thus lowering compression ratio does not increase area at all, and it is always negative to power at constant boost (on same tuning if you are not knock limited etc) I have proven that myself in real life. But you don\'t hae to believe me :) HONDA F1 in 1988 went to 9.0:1 compression ratio on their V6 turbo on 2.5bar absolute pressure from the earlier 7.4:1 on 4 bar absolute pressure and earliest efforts of 6.5:1 on 5 bar + pressure on each and every time the power went up (not the other way around) with higher compression ratio *the opposite of what you are saying* its a thermodynamic fact more work in (compression) = more work out, difference in pressure area graphs is easy to comprehend when you test motors and apply thermodynics principles to them ;) So there is no need on methanol especially to lower the static compression it will just cost you power at the end of the day especially if you are using pressures around 3 bar absolute for example.

Anyway I have added another drag specific set up to the equation.
S5 13B (9.0:1 compression stock rotors) with 4 barrel style intake and BIG TURBO on methanol, street ported tested on engine dyno, peak power at 9250rpm and 917bhp on 32psi intake boost pressure (around 2.207bar boost) 286bhp NA terms (if you work it back to peak power with stock manifold of 7600rpm) works out to 235bhp NA. divide (9250rpm/7600rpm). So you see how all of this makes sense :)

Quote from: Grant Monkhouse;846159Why don\'t a lot of turbo cars run lower compe rotors then? Are their not that many around or is it that the fd rotors are good even at 9.0-1 compression?

Cause its an engineering fact that is COSTS you power, rather than improves it :) especially if you are not limited by fuel type you use.

My personal example of changing out 9.0:1 to 7.8:1 rotors cost almost 10bhp in NA terms on the same set up tuned to MBT ;) but the change did allow the owner to sleep at night knowing his engine was more safe running pump fuel, and it was easy to gain the power lost by a small boost increase :Talking1 and ultimate power can be improved by BIG BOOST INCREASES, just like was done in the 1000bhp F1 turbo era :) and is the aim of this thread! power is proportional to boost increase and you only trim the compression ratio if you are exceeding the limits of the fuel you are using. A good way to know if you are at those limits is work back to your almost ideal NA power level ;) if you are using too much excess fuel ratio or too much spark retard then you NA power level will be down allot .............. its pretty simple that is why I like this method of analysis.

That answers your question WHY? don\'t more people run low compression rotors or pistons, the answer WHY? is it costs power if you are NOT fuel/detonation limited, that is a proven fact :)

To make it clear for layman as well, that NA power (equivalence) is seen all the way up through the boost curve, so a power loss at NA level is seen at say 21psi ;) So in summary you need a couple more psi boost pressure to pick up the power you lost by lowering the compression ratio ;)

If you want/have dreams of running BIG BOOST PRESSURES you will need to look at lower compression ratio\'s OR just like the Air Racers well know, use 130+octane fuel! + WM50 (water injection) to keep here all going :) (or use methanol as the main fuel supply! *easy way out*)

I understand what Carl is saying and also what you are saying Peter. From your example the f1 teams increased comp ratio but lowered boost as they progressed. To achieve the same power outputs ish?? Surely there must be a point at which increasing comp ratio is not good in turbo form anyway. In NA forms 13-1 with race fuel can achieve great power, on v8 anyway:D

I think when Carl means volume he is referring to boost as what you have described, different people have different ways of explaining things.

I think you would both agree on having a lower comp ratio gives tha piece of mind if you are stuck with certain fuels and gain the post HP back with that little but more boost.

That\'s all the old ford nuts over here were doing for years, drop the compression on the pistons and wack the boost up till either the heads lift off the blocks or it explodes.

Trying to make sense of your first posts so I can very roughly guess what I\'ll achieve on my setup.

You need to know your NA HP to work it out Matt. If you have figures from a similar setup as you then you should know what your going to get:)

Unfortunatley I don\'t dude other than it will do 500rwhp minimum at 1bar boost dude. My sister car is still having work done at the mo, all be it mine has a couple of different things though.

The compression ratio is a means to an end.
*If fuel is a limit you need lower compression. (fuel economy eats penis! and power just licks the bag a bit).
*If you are forced to run an arbitrary boost limit (like F1 did in stages) to then make up the power you must INCREASE the compression ratio. (fuel economy massively improves, and power picks up too)
*To run high compression ratio\'s especially at higher boost pressures (I think what Hay is saying? gives power *I hope that is what he was trying to say*) to get the increases in power you want, then you need more and more exotic fuel, high levels of tetra ethyl lead or Methyl Benzene majority based OR Methanol........

That sums up that! now back to PORTING!!!! ;)

Quote from: matt p;846196Unfortunatley I don\'t dude other than it will do 500rwhp minimum at 1bar boost dude. My sister car is still having work done at the mo, all be it mine has a couple of different things though.

That much at 1 bar? What porting?

One of Powergains half bridge ported engines Grant. :)

Quote from: Grant Monkhouse;846203That much at 1 bar? What porting?

quick maths here.

say ~600bhp 2 bar absolute means 300bhp NA!
so needs bridge port and custom inlet manifold and BIG REVS to achieve that goal ;)

Hence the benefit of this thread, you can work it all out pretty quick. :Typing
(this is where the list of proven cars on the first page with normal revs and set ups can be your guide to what is achievable)

There won\'t be a custom inlet, was advised by various people that the custom inlets won\'t be needed as my Cosmo intakes will be good enough for when the boost gets turned up.

Also that won\'t be happening until a water injection system is fitted and more mods to the fuel system.

Only half bridge? Are you using Cosmo ports too? They\'re all big ones :)

That\'s the ones dude, they came of Marc\'s drag setup. Need a little modification and bit of tidying on the elbow but I\'ve sorted that already :)

Quote from: RICE RACING;846185^That is a common mistake most mechanics make.QUOTE]

I am sorry Peter but you are wrong. It is a common misconception that people fall into the trap of especially on turbo engines due to swept volume being the same but potential on turbo engines volume increases.
When the compression is lower the actual chamber volume increases but the swept volume does not due to the combustion chamber still displacing in one steady revolution the same amount.
Think of a piston engine for example, a low comp piston will be physically lower in the cylinder at TDC which means that it will correspondingly be lower at BDC(Meaning same swept volume), but the point is that when at BDC the amount of volume is greater than a high comp piston in the same engine, the only difference is that because the engine runs lower compression it makes less power in N/A form,but as soon as you a strap a turbo on you have a variable compression ratio once above 0 bar N/A and thats where it becomes exciting cos by running higher boost you effectively can make more power by getting more charge mixture into the chamber. Boost level determines whether this is succsessful or not in contrast to higher compression rotors.

Quote from: RICE RACING;846205quick maths here.

say ~600bhp 2 bar absolute means 300bhp NA!
so needs bridge port and custom inlet manifold and BIG REVS to achieve that goal ;)

Hence the benefit of this thread, you can work it all out pretty quick. :Typing
(this is where the list of proven cars on the first page with normal revs and set ups can be your guide to what is achievable)

Doesnt work in the real world though.
You would be lucky to get 250hp in N/A form for that.
Also you need to approx about 1.2 bar to get what N/A would be taking into account that the turbo heats up the air which reduces the actual volume of air.

I think the calculations is based on the same air inlet temp being the same throughout?? I would be very sceptical of an engine making 250+ HP NA on a half bridge. 20B maybe, 13B no way??

Surely people\'s porting techniques change through research allowing for better gains?.

Why would you be sceptic of a half bridge making that?. You know my setup from Fduk so your aware its pretty much there. :)

Quote from: matt p;846392Surely people\'s porting techniques change through research allowing for better gains?.
 
Why would you be sceptic of a half bridge making that?. You know my setup from Fduk so your aware its pretty much there. :)

by using the calculation to give you your NA hp, you are looking at 300engine hp to make 600engine hp at 1 bar boost, 600engine power is roughly 500RWHP.
 
i dont doubt Jay knows what he his doing. but 500RWHP at 1 bar is going to be an awesome achievement, by the calc that also equals 900 engine hp at 2 bar!!
 
why havent you got a thread on here BTW??

If you had two air pumps and turn them on for 2 seconds, one feeding a 5l bottle the other a 10l bottle which one holds more air?
The way i see it, it would be the same but one is under less pressure?

For a road car it is on the high side, but i ask how much power is required for 145mph in a 2800Ib car with driver, forget the dyno graph, i would say it was possible at .8 but it done it!!

Quote from: Grant Monkhouse;846394by using the calculation to give you your NA hp, you are looking at 300engine hp to make 600engine hp at 1 bar boost, 600engine power is roughly 500RWHP.
 
i dont doubt Jay knows what he his doing. but 500RWHP at 1 bar is going to be an awesome achievement, by the calc that also equals 900 engine hp at 2 bar!!
 
why havent you got a thread on here BTW??

Quote from: Grant Monkhouse;846394by using the calculation to give you your NA hp, you are looking at 300engine hp to make 600engine hp at 1 bar boost, 600engine power is roughly 500RWHP.
 
i dont doubt Jay knows what he his doing. but 500RWHP at 1 bar is going to be an awesome achievement, by the calc that also equals 900 engine hp at 2 bar!!
 
why havent you got a thread on here BTW??

I have dude just not updated it in a while:2Confused

Quote from: JayDee;846405For a road car it is on the high side, but i ask how much power is required for 145mph in a 2800Ib car with driver, forget the dyno graph, i would say it was possible at .8 but it done it!!

Huh?

I\'m just working it off the calculation Peter gave. 300fwhp from a half bridge is PP territory. It doesn\'t make sense to me that\'s all.

i think you took that wrong, im saying you would not think that possible at .8. Not using Peters equation, just general calculations using weight and mph

Quote from: Grant Monkhouse;846410Huh?

I\'m just working it off the calculation Peter gave. 300fwhp from a half bridge is PP territory. It doesn\'t make sense to me that\'s all.

Just a quick calculation using Google

http://www.ajdesigner.com/phphorsepower/horsepower_equation_trap_speed_method_horsepower.php

2800lb car/145mph terminal over a quarter mile = 666bhp ish :)

Ah right. Didn\'t understand. James ran 145 at .8ba? That is down to car setup though isn\'t it?

Quote from: matt p;846416Just a quick calculation using Google

http://www.ajdesigner.com/phphorsepower/horsepower_equation_trap_speed_method_horsepower.php

2800lb car/145mph terminal over a quarter mile = 666bhp ish :)

Using that 666hp figure and using peters calculation gives 370hp NA! That\'s 40hp more than previous calc. Something\'s just aren\'t adding up

i know, let me check mph, could have been 140, i\'ll start another thread at some point a bit off topic

Quote from: Grant Monkhouse;846419Using that 666hp figure and using peters calculation gives 370hp NA! That\'s 40hp more than previous calc. Something\'s just aren\'t adding up

Yeh, think I should move these posts into a seperate thread. Peres I to is good, you can learn things from the stuff he posts. You should see the ecu he\'s using now. It\'s insane!

Which ecu is it?

Quote from: Grant Monkhouse;846421Yeh, think I should move these posts into a seperate thread. Peres I to is good, you can learn things from the stuff he posts. You should see the ecu he\'s using now. It\'s insane!

Life racing f88 I think

Oh yes, now your talking

Quote from: Grant Monkhouse;846425Life racing f88 I think

Quote from: Carl;846370

Quote from: RICE RACING;846185^That is a common mistake most mechanics make.QUOTE]

I am sorry Peter but you are wrong. It is a common misconception that people fall into the trap of especially on turbo engines due to swept volume being the same but potential on turbo engines volume increases.
When the compression is lower the actual chamber volume increases but the swept volume does not due to the combustion chamber still displacing in one steady revolution the same amount.
Think of a piston engine for example, a low comp piston will be physically lower in the cylinder at TDC which means that it will correspondingly be lower at BDC(Meaning same swept volume), but the point is that when at BDC the amount of volume is greater than a high comp piston in the same engine, the only difference is that because the engine runs lower compression it makes less power in N/A form,but as soon as you a strap a turbo on you have a variable compression ratio once above 0 bar N/A and thats where it becomes exciting cos by running higher boost you effectively can make more power by getting more charge mixture into the chamber. Boost level determines whether this is succsessful or not in contrast to higher compression rotors.

"Swept Capacity" is the TDC-BDC volumes. Therefore changes in compression ratio do not do in reality or theory what you are saying regardless if it is turbocharged/supercharged at any boost level you care to mention. I explained it all before, you need to re read it and look up some information on the subject, rotary piston etc. It is a hard concept for newbies to get so don\'t feel bad (dont take that as an isult either) as I know lots of people who make this fatal mistake.

Quote from: Carl;846370

Quote from: RICE RACING;846185^That is a common mistake most mechanics make.QUOTE]

I am sorry Peter but you are wrong. It is a common misconception that people fall into the trap of especially on turbo engines due to swept volume being the same but potential on turbo engines volume increases.
When the compression is lower the actual chamber volume increases but the swept volume does not due to the combustion chamber still displacing in one steady revolution the same amount.
Think of a piston engine for example, a low comp piston will be physically lower in the cylinder at TDC which means that it will correspondingly be lower at BDC(Meaning same swept volume), but the point is that when at BDC the amount of volume is greater than a high comp piston in the same engine, the only difference is that because the engine runs lower compression it makes less power in N/A form,but as soon as you a strap a turbo on you have a variable compression ratio once above 0 bar N/A and thats where it becomes exciting cos by running higher boost you effectively can make more power by getting more charge mixture into the chamber. Boost level determines whether this is succsessful or not in contrast to higher compression rotors.

Just though of this to help you:
In Layman\'s terms, think of a cylinder only going half way up the tube then stopping (don mega sized head spacer LOL = low compression from hell!) now you revers the direction and go on the inlet stroke and you only breath in the difference between the TDC volume - the BDC volume, this is why the capacity of an engine does not change regardless of what you do the the compression ratio :)
Now anyone who has actually tested an engine knows that volumetric efficiency (how much of this volume is used) does not change when you cange the compression ratio, boost pressure is a seperate element added ontop and accounted for (as is air density etc, I list it in my figures, again people need to re read it all and take notes), and if you look into it deeper with any level of personal expereince you will know first hand that most turbo systems run more exhaust pressure than inlet pressure, so the ballance of gases want to stay in the dead area rather than go out it by the action of boost (like you claim) so in effect its even worse for the engines efficiencey and without getting into the engineering behind it all I will say is that it is indeed worse the more you lower the compression ratio.

So in summary please do not get upset, the aim is to shcool people who otherwise are mistaken and have no idea how engines actually work :) thermodynamics is the hardest engineering subject for a reason :) most people do not get the concepts.

I think what would make most sense to you is this:
Build a motor and tune it to MBT on 9.0:1 rotors (use race fuel) so you are not limited (by spark timing or air fuel ratio).
Pull it apart and then run it on the same boost! and tune it to MBT, you will find if you use lower compression rotors it will always make less power regardless of the boost pressure, 2,3,4,5 bar or more :)
The opposite is true, fit up some 9.7:1 high comp NA rotors and watch the power go up :)
The capacity has never changed through this process, but the thermal efficiency and power do.... go run some test if you don\'t trust the qualified words of others or F1 engineers :)

Quote from: Grant Monkhouse;846425Life racing f88 I think

Bloody hell, those things look mental!.

Quote from: Grant Monkhouse;846421Yeh, think I should move these posts into a seperate thread. Peres I to is good, you can learn things from the stuff he posts. You should see the ecu he\'s using now. It\'s insane!

Lets have a separate discussion topic around engine compression, I\'d be happy to contribute as can Carl and others on the topic with examples and engineering data of others etc etc.

Same for other off topic discussions around air density or anything to not do with porting.

I generally make the mistake I am talking with engineers, and this is my fault that I think people are on the same page about the actual topic being discussed, and it is all to easy for these to be derailed with (honest questions) from people are confused about the other contributing factors. All legitimate questions btw, they should be addressed but not in a topic where the main point is porting or whatever subject. It just dilutes the discussion is my thought on it.

I will see what I can do and try clean thread up a bit to keep on subject

Sorry, not impressed with the Life racing ECUs.

Mir

Rice, am i correct in saying, if you take a engine and change the compression, The displacement stays the same but what dose changed is the amount that can be compressed at TDC.?

Quote from: Erdin;846439Rice, am i correct in saying, if you take a engine and change the compression, The displacement stays the same but what dose changed is the amount that can be compressed at TDC.?

ZERO :) as you have increased the clearance volume, the engine is starting from a lower point (down the bore) to use a reciprocating term you can picture. You can never properly empty the clearance volume (as defined by Volumetric efficiency) Some porting types have higher volumetric efficiencies in certain rpm ranges, but changing the compression ratio has no net positive effect on this aspect. In fact its proven to reduce power for the reasons I gave, this is universally well known.

What a lot of hog wash kind sir \'RICE RACING\',I have worked out your mathematical  \'google\' calculations here at Nottingham Uni.,actually they hold no concrete evidance to sustantuate your \'beliefs\'. It seems your are most deluded when it comes to Engineering,as a matter of fact you are not even one of the leading ROTARY specialists in Aus.Sorry to say but all your posts are just drivel and you are trying to find an audiance for your ramblings.

After spending the past bloody hour reading this thread I have to agree with carl and a lot of rice racing seems a mixture of copy and paste.

Also is this a video of your expertise
http://m.youtube.com/#/watch?v=CqTMYytvfjk&desktop_uri=%2Fwatch%3Fv%3DCqTMYytvfjk

Quote from: Erdin;846439Rice, am i correct in saying, if you take a engine and change the compression, The displacement stays the same but what dose changed is the amount that can be compressed at TDC.?

Yes but potential volume under boost can be more than with high compression engines. Thats why in F1 turbo engines low compression eg 7.5 to 1 was used which kept det at bay and allowed much higher boost than higher compression engines could take.If high compression was the answer then F1 teams would have done that.EG BMW in the 1980s running 1300hp in qualifying trim in a 1.5 liter 4 cylinder piston engine.
This does not apply to N/A engines where SWEPT volume is a constant no matter what the compression ratio (Apart from the days air pressure)

Look at it this way.
If I was running 7.5 to compression ratio and then was able to run 3 bar over normal air pressure or alternatively was able to run 15.0 to 1 compression but only able to safely run 1.5 bar over normal air pressure which engine everything else being the same including swept volume would make more power?

All that happens with a higher compression engine is the total charge is forced into a smaller space at TDC, the charge then is more likely to to det cos it is alot hotter than a lower compression engine, conversely a lower compression engine can take in more charge at a higher boost level cos when it is compressed it does not get up to the same temp of heat as it would with a higher compression engine. In fact if both engines ran at the same temp once the engine is at TDC you would see more power from the lower compression engine due to alot more air and fuel mix entering the engine which means more BTU\'s are in the charge.
This is for everything else being equal including the det suppression quality or knock level of the fuel. Ontop of this there is more potential room for a greater charge mixture to enter the engine UNDER BOOST.

A big disadvantage of lower compression is that the engine feels lazier off boost and higher boost levels need to be run to get the real potential out of the combination.

Quote from: senodlo;846443What a lot of hog wash kind sir \'RICE RACING\',I have worked out your mathematical  \'google\' calculations here at Nottingham Uni.,actually they hold no concrete evidance to sustantuate your \'beliefs\'. It seems your are most deluded when it comes to Engineering,as a matter of fact you are not even one of the leading ROTARY specialists in Aus.Sorry to say but all your posts are just drivel and you are trying to find an audiance for your ramblings.

Mate, I think you will find rice knows what his talking about. I know for a fact he has been working on rotary\'s for a very long time. I my self have been into rx7 for well over 10 years and he was given advice and help well before that.

His calculations are a guide. I dont believe he is saying this is what your car will make, its to give you an idea.:)

Normal set ups like people would run here, 9.0:1 rotors V\'s 8.5:1 S4 rotors or modified S4 rotors you will always see a power drop when reducing the comp ratio. *remember variables held same so you can ascribe the loss in power to reduced engine compression)

To justify the lower compression you really need to using a very knock limited set up (very poor quality fuel) no water injection etc.

Which is covered in the "tuning caveat I mention in the first few posts :cheers

A real life engine was the Renault F1 turbo engine seen here
http://www.gurneyflap.com/renaultef15.html
Notice that in qualifying they ran lower compression at 7.0 to 1 and were able to run higher boost and make more power than the race engine which ran 7.5 to 1 compression with lower boost.
Why did they do that? Cos it worked for ALOT more power,albeit at the expense of reliablity.

Quote from: RICE RACING;846450Normal set ups like people would run here, 9.0:1 rotors V\'s 8.5:1 S4 rotors or modified S4 rotors you will always see a power drop when reducing the comp ratio. *remember variables held same so you can ascribe the loss in power to reduced engine compression)

To justify the lower compression you really need to using a very knock limited set up (very poor quality fuel) no water injection etc.

Which is covered in the "tuning caveat I mention in the first few posts :cheers

Running lower compression enables much higher boost levels for everything else being the same Peter. The only way to make alot more power is for more ignitable mixture to get into the engine, this can only come with alot more CFM which means boost. If you are running everything else the same then that can only come from lower compression which certainly has the added advantage of allowing alot more workable volume.

Carl this is why when F1 got reduced to 2.5bar absolute (~21psi boost) they all went to 9.0:1 compression ratio\'s from the earlier ~7.4:1 on 4 bar absolute maximum limit.
When fuel was limited they started out on 6.5:1 running AVGAS doctored. All on allot lower power at same boost levels.

If you want a good book to read up on the subject I suggest you look for
The 1000 BHP Grand Prix cars (A Foulis motoring book) (Hardcover)

                          by Ian Bamsey

Quote from: HaywardRotary;846451A real life engine was the Renault F1 turbo engine seen here
http://www.gurneyflap.com/renaultef15.html
Notice that in qualifying they ran lower compression at 7.0 to 1 and were able to run higher boost and make more power than the race engine which ran 7.5 to 1 compression with lower boost.
Why did they do hat? Cos it worked for ALOT more power.

I think this works. Only one way to find out I guess

Quote from: HaywardRotary;846452Running lower compression enables much higher boost levels for everything else being the same Peter. The only way to make alot more power is for more ignitable mixture to get into the engine, this can only come with alot more CFM which means boost. If you are running everything else the same then that can only come from lower compression which certainly has the added advantage of allowing alot more workable volume.

No you are totally wrong. There is NO increase in "workable volume" < this is called the Displacement of the engine and it does NOT change with compression ratio :)

In this link  http://www.gurneyflap.com/zakspeedengine.html
You can see that when boost levels were compulsory reduced for F1 engines manufacturers upped the compression the compensate for the power drop.

We will just have to agree to disagree Peter.:Thumbs-up

This is a good thread however I think allot of people without the engineering background will struggle. Best thing is to keep it all in simple English so everyone can understand.  :driving

Quote from: RICE RACING;846455No you are totally wrong. There is NO increase in "workable volume" < this is called the Displacement of the engine and it does NOT change with compression ratio :)

BTW i have said and agreed with that all along, but you are not taking into account boost level. That is the fundamental difference.

Erm???? By reading both your information I think I can say that you are both talking about the exact same thing. Different explanations.

You both agree that comp went up in the turbo motors when the boost went down to compensate for power loss. Higher comp, less boost equals roughly the same out put. Buuuuut as technology advances and mapping skills advance I bet they made more power from less boost and higher comp?!

Quote from: HaywardRotary;846459We will just have to agree to disagree Peter.:Thumbs-up

That is o.k. :yes
Best thing I say to you is when you have a chance build a 13B and run it on whatever fuel you want use 3 bar absolute boost and simply change out the rotors (use race fuel or pump with WI) and then you will see the difference in power the lower compression gives on the same boost, it will always be lower.
Good luck getting someone to run more than 30psi gauge pressure in a road car set up to make full use of the lower compression ratio benefits it will give.

:burnout

The question then becomes is it needed and at what point? that is a discussion for another thread :Thumbs-up

Let me put it this way, a 1000cc engine displaces 1000cc at atmospheric, but at slightly over 1 bar boost taking into account that the inlet charge is slightly heated the engine now is taking in the equivalent of a 2 liter N/A engine in its capacity, this is where I am saying that the volume increases, but with high compression you reach a limit much earlier for what the engine can injest due to the onset of too much heat all other things being equal.
Lower compression allows more inlet charge to go into that engine than higher compression as I said UNDER BOOST, hence making more power.

Quote from: Grant Monkhouse;846462Erm???? By reading both your information I think I can say that you are both talking about the exact same thing. Different explanations.

You both agree that comp went up in the turbo motors when the boost went down to compensate for power loss. Higher comp, less boost equals roughly the same out put. Buuuuut as technology advances and mapping skills advance I bet they made more power from less boost and higher comp?!

yep i can agree with this. some good stuff from two experienced individuals, good work guys:mmmm

Quote from: Erdin;846465yep i can agree with this. some good stuff from two experienced individuals, good work guys:mmmm

And not one swear word or derogatory comment posted :Ladys-man

Quote from: Grant Monkhouse;846462Erm???? By reading both your information I think I can say that you are both talking about the exact same thing. Different explanations.

You both agree that comp went up in the turbo motors when the boost went down to compensate for power loss. Higher comp, less boost equals roughly the same out put. Buuuuut as technology advances and mapping skills advance I bet they made more power from less boost and higher comp?!

No where near the same output Grant,and that is my point, these engines were running in each form the same capacity,but when the boost level was limited to a much lower amount no amount of upping the compression ratio brought the power level up to what it had been and in F1 they would have ran as high a compression ratio a they could if it had worked better for them.

In our engines we too run into limits but not for boost level with the exception of when the engine dets which is in part caused by boost level and compression ratio.

If you were to fill the "bowl" of a 9.0-1 comp rotor with water and measured that volume of water in ml. Then filled a 7.5-1 comp rotor with water and measured that would they be the same?? That\'s how I always though of as comp ratios, where piston or rotor.

Quote from: RICE RACING;846466And not one swear word or derogatory comment posted :Ladys-man

Good job! This is a family site! LOL:spank

Quote from: RICE RACING;846466And not one swear word or derogatory comment posted :Ladys-man

:Ladys-man:Grrr lol

Quote from: Grant Monkhouse;846468If you were to fill the "bowl" of a 9.0-1 comp rotor with water and measured that volume of water in ml. Then filled a 7.5-1 comp rotor with water and measured that would they be the same?? That\'s how I always though of as comp ratios, where piston or rotor.

Displacement in the rotor in each case is the same but the total volume of the whole chamber is not.
The amount of air/liquid that is pulled in and pushed out is the same, BUT if you were to fill the combustion inlet area when at maximum expansion on the inlet phase with a fluid you would get more fluid into the lower compression engine, but after it is filled it would only physically push out the same total capacity as the higher compression engine.

Quote from: Grant Monkhouse;846468If you were to fill the "bowl" of a 9.0-1 comp rotor with water and measured that volume of water in ml. Then filled a 7.5-1 comp rotor with water and measured that would they be the same?? That\'s how I always though of as comp ratios, where piston or rotor.

But you have to empty the bowl and it is not just poured out like you do down the sink, it is "pumped out" and this is the clearance volume at top dead center, this is a dead area where nothing much happens, it is very hard to clear and in fact never really is very well at if ever.

WORKING Capacity is BDC volume - TDC volume

If you could amazingly increase power by lowering compression ratio, everyone would do it, you only ever can if you are limited by knock limitation of fuel ........... simple.

This is why full race methanol set ups typically do not care to waste time with "low compression" rotor sets, it is counter productive as the fuel is not a limiting factor ;)

See the 13B S5 block I listed making 917bhp on an engine dyno with only 32psi boost pressure used ;)

How about nitro then? They need huge compression to ignite the fuel:D to make the power

Quote from: Grant Monkhouse;846476How about nitro then? They need huge compression to ignite the fuel:D to make the power

they use a methanol mix grant as rich as 2:4 ratio!

Quote from: Erdin;846478they use a methanol mix grant as rich as 2:4 ratio!

RC two stroke is no different, I do allot of development work on that as a hobby lol.

I use 40% Nitro and 60% Methanol (bit of oil added!) anyway. If you use too high a compression ratio you can and DO detonate the engine! Too little compression and the performance is just not there (slower on straights and on dyno).

AFR simple, you measure it the same as you do petrol, I mad a jig to test RC motors and I tune them to 12.7:1 in petrol AFR scale (same as Lambda) the numbers are not important here it is just what has "meaning to the tuner" so anyway with RC 2 strokes they make maximum power around that 0.85 lambda region, but its a balance of head temperature and how the AFR changes over a tank load of fuel in a race etc.

The points are as you increase compression ratio power goes up, but even on 40% Nitro and Methanol as a base fuel it is still prone to detonation ;) small scale or large same thermodynamic principles apply .

Quote from: Erdin;846478they use a methanol mix grant as rich as 2:4 ratio!

Nitomethane you mean, a liquid form of TNT.
They run around 3 to air fuel ratio.
Also they are supercharged. approx 8000 hp
They used to run 100% but gradually to slow the cars down Methanol was introdeiced 1st at 5% and now its 15% so the cars were developed more in the clutch department and now are quicker than ever, so much so that they dont run 1/4 of a mile anymore in the states, they now run 300 meters.

:WaveBye..........

Quote from: RICE RACING;846481RC two stroke is no different, I do allot of development work on that as a hobby lol.

I use 40% Nitro and 60% Methanol (bit of oil added!) anyway. If you use too high a compression ratio you can and DO detonate the engine! Too little compression and the performance is just not there (slower on straights and on dyno).

AFR simple, you measure it the same as you do petrol, I mad a jig to test RC motors and I tune them to 12.7:1 in petrol AFR scale (same as Lambda) the numbers are not important here it is just what has "meaning to the tuner" so anyway with RC 2 strokes they make maximum power around that 0.85 lambda region, but its a balance of head temperature and how the AFR changes over a tank load of fuel in a race etc.

The points are as you increase compression ratio power goes up, but even on 40% Nitro and Methanol as a base fuel it is still prone to detonation ;) small scale or large same thermodynamic principles apply .

But not turbocharged Peter so boost does not come into account here. I also play with these engines and even have 2 rotary engines. 4.9cc and 1.2hp.

Quote from: HaywardRotary;846485Nitomethane you mean, a liquid form of TNT.
They run around 3 to air fuel ratio.
Also they are supercharged. approx 8000 hp
They used to run 100% but gradually to slow the cars down Methanol was introdeiced 1st at 5% and now its 15% so the cars were developed more in the clutch department and now are quicker than ever, so much so that they dont run 1/4 of a mile anymore in the states, they now run 300 meters.

weak! they should run them over a mile!

Quote from: RICE RACING;846488weak! they should run them over a mile!

When Scott Kallitta was killed they changed things, the thing is they are still running the same terminal speeds at 300 meters now as they were at 400 meters before. often 330mph. The shutdown area is longer now cost of running a shorter track.

Scotts crash
http://www.youtube.com/watch?v=ucUL6296Ue0

oops i did mean nitromethane, they are at 1,000ft now but they keep it going through the 1/4 for the show:D

Quote from: HaywardRotary;846487But not turbocharged Peter so boost does not come into account here. I also play with these engines and even have 2 rotary engines. 4.9cc and 1.2hp.

I have had lots of the OS Wankels, too slow for me, I run my own modified AXE Rossi LSK motors fully modified and they make over 3.5bhp @ 26000rpm (runs to 36000rpm), very strong mid range and huge revs and can use proper tuned principles like 2 strokes can, which sadly the wankel can not... all from only 3.5cc.

I mad emy own bored out carburettor lol and crank shaft, and ported the sleeves too, stupidly good fun. I gave up racing mine as always people would come to me at the track to tune theres! and I took up the hobby so people would leave me alone and to destress from working on cars all the time. :yes

You should see my little tuning log, its funny reading back on it, AFR\'s, engine temps, engine rpm, all done through telemetry ! I ran over 20lt of fuel through one engine to prove it, was renoud for completeing a race then filling the car and ripping donuts contstanly for 15 minutes as a victory celebration.

:burnout

We should start up another thread on this alone!

http://www.youtube.com/watch?v=L_WgB9uzz9E
I should say 1000ft now for the top fuelers.
Here is an example of the speed still and look at how short a time it takes to get to 328mph!

Allthough i cant understand everything, this is awesome to read. :)

Just because of professional tuners/builders share opinions, ideas and their knolidge, this rotary community can benefit it.

My opinion is that it really doesent matter who is right or wrong. We (amateurs) can really learn something about this text. And im happy about that :)

Quote from: Mir;846438Sorry, not impressed with the Life racing ECUs.

Mir

Why is that? Currently looking at getting one (well more likely a syvecs version)

R.e. power/ compression ratio, as far as I can see Rice is making the point that higher compression will make more power compared to lower compression if all other variables are kept the same, and even if timing and fuelling is optimised. Intuitively this seems to make sense. However your absolute limit of power will be down to fuel, as the compression (which will be adabatic) will result in temperatures to cause pre ignition/knock. Carl is countering that whilst the power at a set boost will be less, the lower compression allows higher boost to be run before you reach that pre ignition temp in the chamber (again makes sense because you can compress the air in the turbo, then cool it through the intercooler before compressing it in the cylinder/rotor). The downside is that lower compression necessarily means less expansion (in the power stroke) so can\'t take as much work out of the combusting fuel compared to higher compression. Hence th poor fuel economy seen for lower compression motors. I guess the question is which is better overall, running higher compression rotors and less boost, or lower compression rotors and more boost. My gut feeling is higher compression is the more \'correct\' method, but lower compression rotors would give a greater safety factor and probably better for real world applications (accounts for dodgy fuel, small errors in mapping etc).
Carl, Rice, have I understood your points correctly?

Marco, that is the essence of what both of us have been frothing about :Talking1

But I was more interested in porting  :mmmm This topic alone generates much excitement where people literally want to stab each other in the heart and urinate on the decapitated corpse of anyone who dares put forth an alternate view hahaha

p.s. what is better, my own feeling is I always go with lower compression, this is why I never use 9.7:1 high comp NA rotors in any of my builds like some love to do. 9.0:1 is great (best of both worlds) and for mental people who have a death wish then I go the custom RR developed 7.8:1 (modified S4 set). It just depends what the car is for and mostly the fuel type used.

With regards to porting, what is your take on beveled/scalloped rotors to modify the timing and duration rather than the plates?

Quote from: marco;846531With regards to porting, what is your take on beveled/scalloped rotors to modify the timing and duration rather than the plates?

I do allot of it, listed all of the details on one irrelevant site many years ago with timing changes it gives and effects. on mine I scallop the intake open edge and closing edge, it is also a good way to make fine adjustments to the compression ratio as well ;)

Don\'t suppose you have a link to the site do you? I am trying to get my head round them!

Quote from: RICE RACING;846532I do allot of it, listed all of the details on one irrelevant site many years ago with timing changes it gives and effects. on mine I scallop the intake open edge and closing edge, it is also a good way to make fine adjustments to the compression ratio as well ;)

Will you be using scalloped rotors in your next build?

Is the scallops what brings your street ports to match and some times beat bridge ports in peak HP?

Quote from: Grant Monkhouse;846537Will you be using scalloped rotors in your next build?

Is the scallops what brings your street ports to match and some times beat bridge ports in peak HP?

Which is why my car has them:Giggle

Quote from: Erdin;846539Which is why my car has them:Giggle

Oooo but what it someone scallops and bridges?! :censored::censored::censored::censored: on your bonfire won\'t it. Haha jokes

Quote from: Grant Monkhouse;846540Oooo but what it someone scallops and bridges?! :censored::censored::censored::censored: on your bonfire won\'t it. Haha jokes

LOOOL:rollin

Quote from: marco;846528Why is that?

One of my mate on a Supra forum sold one- he got F88 ECU after he sold his Motec M800 ECU. After runing his car on the F88 ecu, he didn\'t feel any substantial difference and decided to go back to MOTEC.

I can\'t remember, but he also had problems with the support team or something.

Before going Motec route myself, I did a lot of research on ECUs and Motec ticked loads of boxes for me.

On the other hand, I am a big fan of Motec and Haltec ECUs, so my dislike can also be motivated by the Love of Motec and Haltec loll

Mir

Quote from: Mir;846559One of my mate on a Supra forum sold one- he got F88 ECU after he sold his Motec M800 ECU. After runing his car on the F88 ecu, he didn\'t feel any substantial difference and decided to go back to MOTEC.

I can\'t remember, but he also had problems with the support team or something.

Before going Motec route myself, I did a lot of research on ECUs and Motec ticked loads of boxes for me.

On the other hand, I am a big fan of Motec and Haltec ECUs, so my dislike can also be motivated by the Love of Motec and Haltec loll

Mir

so being no worse than motec is a bad thing?!?

From what I understand life racing, syvecs are above the motec platform, they are for people that don\'t require help from the makers. They are somewhat near the level of pectel ECUs I think. You have all the options old too you. You don\'t have to pay to access features all ready on the ecu

Quote from: Grant Monkhouse;846562You don\'t have to pay to access features all ready on the ecu

I would say, everything has it\'s pros and cons. However, I do agree with Grant above.

Ok, i´m trying to understand all of this...

I do understand both of those methods. I thought that big boost will be fatal to e-shaft and can brake housing to leak to waterchannels. Similar problem in piston engines is headgascet failure. But they can use tougher material in it. I cant understand how that problem can be fixed in rotarys...?

"Only" turbo rotary tuner here (in Finland) said that rotarys cant take more than 1,6bar boost. That in mind, i would use high compression rotors, cause i cant use high boost. In piston engines i could use lower compression, cause i can go with higher boost. Knockin, pre ignition and so on can be fixed with good ecu.

I know that rotarys can take more boost than 1,6bar, but i really dont know how you do that. I have said before that i really dont care about max power, i really want the engine work perfectly in that job that it is built for. As for turbocharcing, i dont know s**t about it. And seems like i dont know anything about rotarys, but im trying to learn :)

Amount of boost is dictated by you fuel type, you tuner, your engine spec, your ancillaries. Etc. methanol engines are running in the range of 65psi if you look in the right places:) :D

Quote from: re japi;846587Ok, i´m trying to understand all of this...

I do understand both of those methods. I thought that big boost will be fatal to e-shaft and can brake housing to leak to waterchannels. Similar problem in piston engines is headgascet failure. But they can use tougher material in it. I cant understand how that problem can be fixed in rotarys...?

"Only" turbo rotary tuner here (in Finland) said that rotarys cant take more than 1,6bar boost. That in mind, i would use high compression rotors, cause i cant use high boost. In piston engines i could use lower compression, cause i can go with higher boost. Knockin, pre ignition and so on can be fixed with good ecu.

I know that rotarys can take more boost than 1,6bar, but i really dont know how you do that. I have said before that i really dont care about max power, i really want the engine work perfectly in that job that it is built for. As for turbocharcing, i dont know s**t about it. And seems like i dont know anything about rotarys, but im trying to learn :)

VS Motor? (Can\'t remember if he is Norway or Finland? I helped a worker of his make his S5 engine reliable, they followed my set up and ran that motor to 2.0bar with water injection and pump petrol on 9.0:1 rotors, it is one I use figures on the first post as he sent me the engine dyno report many years ago now.

To reliably & durably do this long term rotaries need water injection :cheers

The limit for totally stock no side clearance\'d rotors is around 2.3 bar boost (gauge pressure) and 8000rpm, this is even using the latest mazda rotors with the extra side steps next the main rotor lands. Anyway more boost than this on stock ports combined with revs simply means the rotor sides crash into the side plates costing power and wearing the crap out of everything. Simple fix, side clearnce the rotors, then you can allow the movement and use much more boost/revs/power.

VS Motor is in Norway. Here is just local guy, who does rotarys just because he likes them...

Ok, i have read this topic like 100 times, 3 times today. My head hurts... :)

I just cant understand how engine can take so much air, just with higher boost to make those kind of power? There must be some kind of restriction in somepoint. Engine ports has to make a differense how much air is flowing in to compustion chamber. Power cant just go up in linear line with adding boost...

That why i just dont understand those numbers in first page of this topic. And im not sure can i explain my thoughts correctly... :/

Btw, has anyone just tryed to take of a turbo from FD and dyno it to see how much power it has?

Quote from: re japi;846594VS Motor is in Norway. Here is just local guy, who does rotarys just because he likes them...

Ok, i have read this topic like 100 times, 3 times today. My head hurts... :)

I just cant understand how engine can take so much air, just with higher boost to make those kind of power? There must be some kind of restriction in somepoint. Engine ports has to make a differense how much air is flowing in to compustion chamber. Power cant just go up in linear line with adding boost...

That why i just dont understand those numbers in first page of this topic. And im not sure can i explain my thoughts correctly... :/

Btw, has anyone just tryed to take of a turbo from FD and dyno it to see how much power it has?

What most people forget is that as pressure increases flow becomes less important (what I mean by that is) flow as you would know it in NA terms ;)

You only need to look at my test on the stock 13B-REW, same everything air box, air filter, exhaust system!, stock engine, the only thing changed is a turbo that can deliver the air at the higher pressure ratio\'s, the concept if proven 100% :Tongue1

Only thing stock ports limit is the "range" of the engine (revs) and also the volumetric efficiency (as shown in the power to NA terms). And in simple language this just means you need to use more boost to make the same peak power v\'s a street port, or semi bridge or partial pp etc. *just read all the power figures* and boost used to reach them.

Power bands and power from low revs, well that is another debate lol. The prove is in the transient response and VBOX proven data for acceleration from 4500rpm to 8000rpm or the 90kmh to 140kmh real world test in 3rd gear.......... this is where the BS stops and all the theories get put to the test 100kmh to 200kmh is a nice test too ;)

:3gears-rh :burnout

And to your high lighted point I have proven it does go up in a linear point, if charge temp is kept the same and tuning is the same (same timing and AFR) it is near enough linear, I list all these variables ;)

It\'s just a suggestion:

can we have a breakdown of info please just like the first page of this thread. For example:

Such Rotor Midifications can be carried out:
S4 low compression rotors
advantages: xxxx
disadvantages:xxx
To what extent it can be modified: xxxx
Why you can\'t go above such modifications: xxxx
Good for what sort of an engine: bridge port, street port etc etc
Things to avoid when modifying them: xxxx
Advise regarding Re Build gasKits for such rotors:xxx
Advise regarding Apex Seals when using such modified rotors: xxxx
Advise regarding boost figures: xxx

High Compression Rotors:
As above explanation might help.

it may be I, but I tend to understand things that way easily.
 
 Mir

edit: I know it might be alot to ask but it helps alot when compared with understanding a whole paragraph which includes engineering terminology. Too much for a layman to understand :-(

Thats a lot of kisses Syed!!

Quote from: Mir;846597It\'s just a suggestion:

can we have a breakdown of info please just like the first page of this thread. For example:

Such Rotor Midifications can be carried out:
S4 low compression rotors
advantages: xxxx
disadvantages:xxx
To what extent it can be modified: xxxx
Why you can\'t go above such modifications: xxxx
Good for what sort of an engine: bridge port, street port etc etc
Things to avoid when modifying them: xxxx
Advise regarding Re Build gasKits for such rotors:xxx
Advise regarding Apex Seals when using such modified rotors: xxxx
Advise regarding boost figures: xxx

it may be I, but I tend to understand things that way easily.
 
 Mir

This gets complex, but I will try to keep it simple enough, for road cars and even some track cars, the POWER CURVE is important, and not to just focus on peak power numbers, IF you can keep the power curve it is a very simple physics relationship that if you double the power you will halve the time and halve the distance needed to accelerate to a certain speed.

The big problem is people go about lifting the power the wrong way and diminish the power curve of the engine as they increase the power (typical problem on turbo cars especially with mis matched turbo and screwed up porting styles) and when you give it back to the owner he wonders why the "dyno sheet" increase does not correspond with the actual vehicle performance.

This is why I invested allot of ca$h in the best Race Logic VBOX equipment and test from a different perspective to all others, I focus on car performance and back it up with actual vehicular tests and how the power makes an effect on it, and all of it backs the other up to a T. In many cases most dyno sheets you get never back up reality.

Quote from: RICE RACING;846062Race Logic VBOX proven ;)

Anyway this year *time pending* the power train set up is being optimized further, still looking 100% standard factory RX7SP under the hood
(http://img42.imageshack.us/img42/1723/img3815donmega.jpg)
:coolgleamA: just more power with matching performance increase (not just token BS dyno sheet guesses that don\'t add up with reality like others lol).

100kmh to 200kmh in sub 5 second range? ......... wif 13B in a real road car not running jizz juice? :fawk:
check the FAST FD thread :willy_nilly:

http://rotarycarclub.com/rotary_forum/showthread.php?t=14704

Acceleration tests of FD rotary RX7\'s (VBOX data only accepted) verified by RICE RACING.
Only will accept flat road runs, any downward slopes greater then ~1.5 degree\'s over the length of the test will be rejected
Ranked FASTEST to SLOWEST
A little background information on acceleration times in gear/s: To do half the time of a stock weight FD you need basically double the power (simple), if you can do it in 1/3rd of the time you need 3 times the power (simple again) and so on it goes..... In your VBOX log the distance taken to achieve the speed is also exactly half if you had half the time taken, thus double the power (see proven example at end of post) eg: double the power also equals double the acceleration (Longitudinal G force average) *IT ALL ADDS UP IN REALITY! real world testing!!!*. These test really do separate the bullcrap(dyno sheets) from the reality of practical acceleration tests.SEE EXAMPLE TEST @ BOTTOM OF THIS POST

[SIZE=9]OFFICIAL LIST[/SIZE]
100kmh to 200kmh (Any gear or gears you like!)
User name - Time (seconds) - basic spec
smg944 - 5.12 sec - C16 water injected 27psi 525rwhp http://www.rotarycarclub.com/rotary_forum/showthread.php?t=14704
RICE RACING - 5.70 sec -  93 oct water injected 31psi run stock standard 13B-REW http://www.riceracing.com.au/RiceSPGallery.htm
Ferrari ENZO - 5.80 sec - Blueprinted rebuilt motor (est 687bhp, 1505kg run weight) >  http://www.ferrarichat.com/forum/showthread.php?p=141406422&posted=1#post141406422
"A new engine is $250K USD and a re-built one from the factory is about $150K. We did ours for under $100K."
Ferrari ENZO - 6.20 sec - Factory motor > http://www.ferrarichat.com/forum/showthread.php?p=141406422&posted=1#post141406422
RICE RACING - 6.25 sec -  93 oct water injected 24psi run stock standard 13B-REW http://www.aquamist.co.uk/vbulletin/showthread.php?t=1590&page=3
smg944 - 6.39 sec - 93 oct water injected 23psi 473rwhp
Ferrari F40 - 6.74sec sec - The super car reference, 1421kg run weight ~500bhp catless  http://www.carobu.com/F40%20LM%20510hp%20dyno.html
Docmar - 6.90 sec - 93 oct 22psi 2 people in car http://www.rotarycarclub.com/rotary_forum/showthread.php?t=14704&page=3
smg944 - 8.27 sec - 93 oct 16psi gt35r medium street port 407whp
smg944 - 9.08 sec - 93 oct 16psi my streetported motor, stock twins non seq PFC
Jose - 9.52 sec - 93 oct 17psi streetported motor t04e or 57mm turbo
Dan McVicker - 9.99 sec - 93 oct 12psi streetported motor copy T04R or 67mm turbo 235~240rwkw VBOX power 1385kg test weight
Nathan - 10.82 sec - 93 oct 18.5psi RF420 twins
Kila13B - 15.52 sec - 93 oct 15psi 100% stock std RX7 Spirit R Type A





90mh to 140kmh (3rd gear only) power band acceleration test ~4500rpm to ~8000rpm < *rough rpm range* for typical FD\'s
User name - Time (seconds) - basic spec
smg944 - 1.83sec sec - C16 water injected 27psi 525rwhp *NOTE* unofficial as 3 to 2.5 degree down slope over run
RICE RACING - 1.91sec -  93 oct water injected 31psi run stock standard 13B-REW http://imageshack.us/f/806/191secvbox30psisicbro.jpg
smg944 - 2.18 sec - C16 water injected 27psi 525rwhp
RICE RACING - 2.26 sec -  93 oct water injected 24psi run stock standard 13B-REW
smg944 - 2.59 sec -  93 oct water injected 23psi 473rwhp
Nathan - 3.25 sec - 93 oct 18.5psi RF420 twins http://www.riceracing.com.au/vbox-iii-testing-tuning.htm
smg944 - 3.26 sec - 93 oct 16psi gt35r medium street port 407whp
Jose - 3.48 sec - 93 oct 17psi streetported motor t04e or 57mm turbo
Dan McVicker - 3.81 sec - 93 oct 12psi streetported motor copy T04R or 67mm turbo 235~240rwkw VBOX power 1385kg test weight
Russ - 4.21 sec - 93 oct 10psi stock port motor BNR TWINS
Kila13B - 5.70 sec - 93 oct 15psi 100% stock std RX7 Spirit R Type A http://www.riceracing.com.au/vbox-iii-testing-tuning.htm
Docmar -


OFFICIAL LIST of some real fast tuned & factory super cars & a few :censored::censored::censored::censored: box porsches mixed in as well
(http://img51.imageshack.us/img51/9423/performancetable.gif)

EXAMPLE TEST OF PROOF OF POWER RELATIONSHIP TO TIMES TAKEN TO ACCELERATE
This is another interesting comparison: From my collection of VBOX tests http://www.riceracing.com.au/vbox-iii-testing-tuning.htm
90kmh to 135kmh (best power gearing for the stock RX7) see rpm logging.

RICESP V Spirit R Type A (stock standard)

Car specs:
Spirit R Type A
1335kg as run
280PS factory rated engine (100% stock std no mods at all)
Car ran 0-100kmh in 5.55 seconds & 13.85 second @ 104.78mph RR V-BOX Recorded for 1/4 mile *no roll out*
Time = 5.06 seconds & 158 meters

RICESP:
~21psi Rice Racing Engineered Water Injected Monster :)
1310kg as run
Power is over double a factory RX7 (see actual VBOX RR rwkw measure) so roughly double the power, double the acceleration & half the time required to do it and distance as well :)
Time = 2.21 seconds & 69 meters

VBOX File report
(http://img864.imageshack.us/img864/7387/ricespvspirtrrtypeastoc.jpg)

Another power analysis graph of RICESP using VBOX3i instrument
This is another interesting comparison: From my collection of VBOX tests http://www.riceracing.com.au/vbox-iii-testing-tuning.htm
Here is the 3 rd gear acceleration of the stock RX7 SP, tested by Motor Magazine with Correvit digital timing.

RX7SP stock 1995 test
204kw
276bhp claimed power factory rated engine (100% stock std no mods at all)

100kmh = 0 sec
110kmh = 0.87 sec
120kmh = 1.83 sec
130kmh = 2.84 sec
140kmh = 4.58 sec

RICESP
You guess the power :)

100kmh = 0 sec
110kmh = 0.51 sec
120kmh = 0.99 sec
130kmh = 1.51 sec
140kmh = 2.01 sec

(http://www.ausrotary.com/images/reference/rx7sp/motor/motor9e.jpg)

VBOX proof of my figures at mid range boost on our list, HIGH BOOST VBOX runs to come stay tuned :)
O.K. Remember pump petrol/gasoline here only ! ***OFFICIAL VBOX test results***

90kmh-140kmh = 2.26 seconds!
100kmh-150kmh = 2.39 seoconds!
100kmh-200kmh = 6.25 seconds!

(http://img341.imageshack.us/img341/6964/img3966don1.jpg)

(http://img269.imageshack.us/img269/7215/img3886don1.jpg)

Still on old tires, and showing about 24psi boost on the VBOX, and ~330rwkw VBOX POWER

Tested at 1320kg run weight and 25 deg C ambient day, still doing boost learning procedure so there is a bit more in at this level and fuel mixture set rich to be on safe side.

Fact V\'s Fiction

Will put up some VBOX graphs when I get them off the lap dancer top

That summarized means a car with a good power curve will be faster on the street than a far more powerful one fitted with a peaky bridge port and 600+rwhp and not using much more boost either. And in real world situations the power curve is much better so you can overtake cars easily in high gears.

Post number 148 here > http://www.aquamist.co.uk/vbulletin/showthread.php?t=1590&page=15 proves it and you can read the analysis if you so wish.

This shows that YES 100% you can use a turbo and simply increase the pressure and keep the widest possible power band and have as much power as you need.

Quote from: JayDee;846600Thats a lot of kisses Syed!!

Pmsl rofl lol :Giggle:Thumbsup!:spank

Quote from: Erdin;846539Which is why my car has them:Giggle

scalloped and semi pp....winner!!!:WaveBye

Quote from: Ed_RX7parts;846619scalloped and semi pp....winner!!!:WaveBye

That\'s nothing, I am thinking of scalloped rotors and full pp*








*yes, I am just seeing if I can get someone to bite...

lol...thing is ive already bitten...c\'mon...i want my car back!!

Quote from: Ed_RX7parts;846621lol...thing is ive already bitten...c\'mon...i want my car back!!

Ed, I wish you luck with it, but I am not sure whether you are ready for the power of it or not!! I have said that before, that thing will be stupidly fast.:god

Mir

Quote from: JayDee;846600Thats a lot of kisses Syed!!

Yeah forgot to send some your way too.. So here they are loads of kisses for your awesome tuning skills xxxxxx :)

Edited and warning given

Should I start the FAST FD thread here where it\'s measuring some quick in gear times for road going cars, using a VBOX????

Quote from: RICE RACING;846625Should I start the FAST FD thread here where it\'s measuring some quick in gear times for road going cars, using a VBOX????

Yes please. It would be nice:King

Mir

Edit: I have no association with the comments of senodlo

Quote from: Mir;846627Yes please. It would be nice:King

No problem, I\'ll get on it, what section is best?

General and Technical. We can always move it to the other section by requesting to the relevant mod.

Mir

Quote from: Mir;846597It\'s just a suggestion:

can we have a breakdown of info please just like the first page of this thread. For example:

Such Rotor Midifications can be carried out:
S4 low compression rotors
advantages: xxxx
disadvantages:xxx
To what extent it can be modified: xxxx
Why you can\'t go above such modifications: xxxx
Good for what sort of an engine: bridge port, street port etc etc
Things to avoid when modifying them: xxxx
Advise regarding Re Build gasKits for such rotors:xxx
Advise regarding Apex Seals when using such modified rotors: xxxx
Advise regarding boost figures: xxx

High Compression Rotors:
As above explanation might help.

it may be I, but I tend to understand things that way easily.
 
 Mir

edit: I know it might be alot to ask but it helps alot when compared with understanding a whole paragraph which includes engineering terminology. Too much for a layman to understand :-(

That is a good idea, lot of work to do it though, and the "comments" would be :guinness

Maybe you can start a thread using the format you like above and others with "comments" can contribute their seemingly endless knowledge on all topics :Typing

Quick question what engine oil do you use and what would you recommend ,  mineral or synthetic oil,

Quote from: 787b;846632Quick question what engine oil do you use and what would you recommend ,  mineral or synthetic oil,

I was just reading that thread!
hahaha ;) *stalker*

im very interested to know what people run when you see the amount of money and time spent on building these engines :Thumbs-up

im not stalking lol  just been reading this complete thread which is very deep and wanted to know what your views are on  engine oil and what types :Thumbs-up

umm... :/ i just dont get it... lol

Still, this is awesome topic. I can learn lot from it... :)

Btw, Mir. I just looked "My Dream Project: http://www.rx7club.com/build-threads...roject-970923/ ". That thing is AWESOME! :D

Quote from: re japi;846640Btw, Mir. I just looked "My Dream Project: http://www.rx7club.com/build-threads...roject-970923/ ". That thing is AWESOME! :D

one day I will have such sort of an FD. I am working towards it and currently buying as many things as I can.. Once my shopping completes, I will break my car and then rebuild it to such standard. If you meticulously read the build thread, you will see the amount of money that has been invested in that project.

In my opinion, no fd compares the Chips fd-end off. It\'s my dream fd. However, I do have a reservation on the body kit used thou! :/

Gentlemen please read.

To everyone who\'s expressed interest on the CLR. Rotors.
The following is a bit of history, background, development, and advantages of the product.

These Rotors are a result of years of R&D on both Hi-output Turbocharged and NA. Rotary engines.

Originally intended for ITA competition, an idea to gain port timing was developed.
Once proven, it quickly found it\'s way into and adopted by certain SCCA
E-Prod. & GT-3 National Champions.


CLR\'s development and applications of this technology dates back to 1988\'

Now that Mazda has applied this tech. to the Rx8 for the same basic porpose, suddenly the "CAT WAS LET OUT OF THE BAG" .
We were forced to go public with information about this tech.
Reputable engine builders have reported averages of 25 Hp. gains on NA. Side port engines

Our first attempt with "Rotor Port Phazing" on Turbo engines came in 94\'.
We saw a tremendous increase in performance, especially when conbined with properly sized Turbos & Injectors.
Further testing PROVED, radical increases in VE. at higher engine speeds.

The Rotor pictured above, resulted from a request to develop a "Reliable", daily driven, 600 BHp. Street engine to run on Pump Gas.
The outcome neted several street cars runing excess of 22 Psi. Boost, and well over
500 RWHp., ON PUMP GAS, for years on end !
All who have tryed these Rotors w/ Turbos have reported massive power gains over their previous engine setups.

Within the last few years, 3 of the top 4 Rotary Drag Racers in the country have broken many a record runing these Rotors.
One went on to win the NHRA Outlaw RWD. National Chanpionship.

Advantages of the product are:

a) A thicker, more stable & durable casting, cloned to REW. weight.
Staticly balanced to the gram, and Dynamicly balanced to work w/ REW.
Counter weights.
b) Clearenced for sustained Hi-Rpm operation.
c) Rotor port phazing, otherwise known as "scalops" allow for earlier and longer
Intake port timing duration.
The "scalops" open the Intake port, while the Rotor is physically on an
otherwise MUCH LATER crank angle. Effectivly blooking the exhaust port by the
Rotor\'s flanks, adjesent to the chamber. Thereby significantly reducing Exhaust
cross flow contamination into the Intake cycle, due to backpresure.
Delivering lower EGT\'s, & Charge Air Temps. which yeild a dencer charge.
d) Last, a Lower Compression ratio, tolerates much higher Boost levels and
further supresses heat and presure induced Detonation or Pre-ignition.

There are those who will argue that lower compression yeilds a "softer" bottom end and throttle responce,...........
Not the case, these are TUNING ISSUES that can be "Maped out" with proper understanding of what a low comp. engine requires while off boost.
With today\'s readily available EMS\'s. and tunig capabilities, that\'s no longer a valid point.
On the flip side of that argument, a single Pound of more boost, will MORE THAN make up for any lack of bottom end. Add in the the benefit of running MORE Boost, MORE often, for MORE sustained periods of time. Most will agree, their is NO argument.

The "Scalop Rotor" modifications is only effective on Side port engines.
And offer absolutly NO ADVANTAGE on full Peripheral Port configurations.
For further information, contact CLR. Motorsports, or send a PM.


GT1-20b
CLR. Motorsports Inc.
Miami, Fl. [/COLOR]

Where did the talk of porting go?

All i see is talk of rotors and compression ratios. Surely this isn\'t affected by porting?

Also, i dont really see how this thread can be of use to anyone due to the huge amount of jibberish.

If your an engineer, then thats cool, but if your aim was to get people interested in your business who are new to the rotary scene then surely you should register ad a trader and have your own section on the forum like Carl has for questions/advertising.

I\'m more confused now than I was before reading page 1.

Quote from: cona2k;846446Also is this a video of your expertise
http://m.youtube.com/#/watch?v=CqTMYytvfjk&desktop_uri=%2Fwatch%3Fv%3DCqTMYytvfjk

Liam, good find! Made my evening! If Rice Racing driving is as good as his porting techniques, I wouldnt be touching him with a bargepole...

You do realise that Rice is all the way over in australia right?? As with many threads they tend to go off at a tangent at times.

Quote from: DJ Tommo;846699Where did the talk of porting go?

All i see is talk of rotors and compression ratios. Surely this isn\'t affected by porting?

Also, i dont really see how this thread can be of use to anyone due to the huge amount of jibberish.

If your an engineer, then thats cool, but if your aim was to get people interested in your business who are new to the rotary scene then surely you should register ad a trader and have your own section on the forum like Carl has for questions/advertising.

I\'m more confused now than I was before reading page 1.



Liam, good find! Made my evening! If Rice Racing driving is as good as his porting techniques, I wouldnt be touching him with a bargepole...

I really don\'t see why you have bothered posting Tommo, if you had a question on any of the subjects then fair enough but to pop up, slate someone you don\'t know then disappear is honestly pointless. As far as I can see your post is the only jibberish here, at least others have asked questions about the subjects being discussed.

If the information is too hard for you to understand then don\'t bother looking at it. Or I could alternatively point you in the direction of some pop up books?

Would be good to hear more thoughts on porting :)

The parts about scalloping the rotors was interesting, bit like cutting in valve cuts on pistons for higher revs :)

Quote from: Grant Monkhouse;846705You do realise that Rice is all the way over in australia right??

Very aware, thanks for taking time to point out that pointless piece of information.

Quote from: Grant Monkhouse;846705I really don\'t see why you have bothered posting Tommo, if you had a question on any of the subjects then fair enough but to pop up, slate someone you don\'t know then disappear is honestly pointless. As far as I can see your post is the only jibberish here, at least others have asked questions about the subjects being discussed.

If the information is too hard for you to understand then don\'t bother looking at it. Or I could alternatively point you in the direction of some pop up books?

Yes, but replying to my pointless post with you pointless post is pointless in itself as it is still off topic. If you read my post, there is a question. If you have a problem with me, deal with it off the forum please in a polite manner. You can PM me on FDUK if you like. No need to get your knickers in a twist with me asking a question. Also where have I "disappeared" to? I\'m still here...

I want MOAR info about porting please because that what I wanna read about. Start another thread as discussed earlier for compression ratios and . Unless like i said there is a correlation between compression ratios and the port size? (as per last post) In which case, continue and I will try to read and get a better understanding. What about J port setups?

After re-reading the "scallop rotor" mods do sound interesting. In fact, they sound pretty damn awesome. Thumbs up!

I\'m happy with the "Hungry Caterpillar" thank you very much...;)

Quote from: DJ Tommo;846718Very aware, thanks for taking time to point out that pointless piece of information.



Yes, but replying to my pointless post with you pointless post is pointless in itself as it is still off topic. If you read my post, there is a question. If you have a problem with me, deal with it off the forum please in a polite manner. You can PM me on FDUK if you like. No need to get your knickers in a twist with me asking a question. Also where have I "disappeared" to? I\'m still here...

I want MOAR info about porting please because that what I wanna read about. Start another thread as discussed earlier for compression ratios and . Unless like i said there is a correlation between compression ratios and the port size? (as per last post) In which case, continue and I will try to read and get a better understanding. What about J port setups?

After re-reading the "scallop rotor" mods do sound interesting. In fact, they sound pretty damn awesome. Thumbs up!

I\'m happy with the "Hungry Caterpillar" thank you very much...;)

Quote from: Grant Monkhouse;846708I really don\'t see why you have bothered posting Tommo, if you had a question on any of the subjects then fair enough but to pop up, slate someone you don\'t know then disappear is honestly pointless. As far as I can see your post is the only jibberish here, at least others have asked questions about the subjects being discussed.

If the information is too hard for you to understand then don\'t bother looking at it. Or I could alternatively point you in the direction of some pop up books?

Guys this is a good thread, lets not :censored::censored::censored::censored::censored: on here.

For dose that don\'t agree with what is being discuses, please keep things professional and explain your opines and reasons.

Quote from: DJ Tommo;846718Yes, but replying to my pointless post with you pointless post is pointless in itself as it is still off topic.

Then why did you make a pointless post in the first place?

Also, describing detailed data and logical conclusions from such data isn\'t gibberish.  If you can\'t take them time to try to understand it, that\'s not the poster\'s problem.  Inevitably any discussion of relative tuning techniques is going to hive off down any number of increasingly complex avenues.  There are many better ways to steer a discussion than the one you employed.

Back to the Topic in hand.

My question alas remains an answered.


Does porting affect compression ratio? and does he have an example of a J port design?

Back to topic...

Compression ratio is dictated by the bowl of the rotor.

Porting is on the side plate.

Blitz and rob have an example of a j port so they could posts their results. It\'s about everyone sharing info. Not just rice.

Quote from: DJ Tommo;846736My question alas remains an answered.


Does porting affect compression ratio? and does he have an example of a J port design?

Back to topic...

Modified inlet porting does not affect compression ratio. Scalloping the rotors does.

Quote from: HaywardRotary;846739Modified inlet porting does not affect compression ratio. Scalloping the rotors does.

This I can understand, thankyou Carl and thankyou Grant:Thumbs-up

Had a read, understanding more now, am I right in thinking though that an n/a engine makes power in a completely different way though? And a turbo engine runs like poop without boost, so will never make it`s theoretical n/a power equivalent, add the whole compression ratio thing into it and it`s all cream crackered? How can these results/calculations be 100% or is it dependent on something like intake temps?

Forgive me if this has been asked already.

Quote from: DJ Tommo;846741This I can understand, thankyou Carl and thankyou Grant:Thumbs-up

Had a read, understanding more now, am I right in thinking though that an n/a engine makes power in a completely different way though? And a turbo engine runs like poop without boost, so will never make it`s theoretical n/a power equivalent, add the whole compression ratio thing into it and it`s all cream crackered? How can these results/calculations be 100% or is it dependent on something like intake temps?

Forgive me if this has been asked already.

Hi Tommo,

The calculations are based on ideal situations but as we know there are no such thing as an ideal situation as air temp, water temp and other factors will change things. hope that helps:Thumbs-up

N/A engines are running at 1bar absolute air pressure.
Turbo engines start at that and then as the turbo comes in the boost pressure varies from 1 bar absolute to gradually increasing as the revs and load increase to whatever it is set to run at in a controlled way.
all boost guages measure boost after it has gone over 1 bar absolute, so for example if you are running 14.7 (1bar) psi boost on your guage you are actually running 29.4 psi (2 bar) as measured including absolute air pressure.

Quote from: DJ Tommo;846741This I can understand, thankyou Carl and thankyou Grant:Thumbs-up

Had a read, understanding more now, am I right in thinking though that an n/a engine makes power in a completely different way though? And a turbo engine runs like poop without boost, so will never make it`s theoretical n/a power equivalent, add the whole compression ratio thing into it and it`s all cream crackered? How can these results/calculations be 100% or is it dependent on something like intake temps?

Forgive me if this has been asked already.

Quote from: HaywardRotary;846743N/A engines are running at 1bar absolute air pressure.
Turbo engines start at that and then as the turbo comes in the boost pressure varies from 1 bar absolute to gradually increasing as the revs and load increase to whatever it is set to run at in a controlled way.
all boost guages measure boost after it has gone over 1 bar absolute, so for example if you are running 14.7 (1bar) psi boost on your guage you are actually running 29.4 psi (2 bar) as measured including absolute air pressure.

And just to add N/A 1 bar is 1 bar atmosphere at sea level, if im not mistaken.

Quote from: Grant Monkhouse;846738Blitz and rob have an example of a j port so they could posts their results. It\'s about everyone sharing info. Not just rice.

Do they???

Both are bridgeports dude

:/

Quote from: Grant Monkhouse;846738Compression ratio is dictated by the bowl of the rotor.

Porting is on the side plate.

Blitz and rob have an example of a j port so they could posts their results. It\'s about everyone sharing info. Not just rice.

Thought Marco was running full bridge :)

Quote from: colum;846747Do they???

Both are bridgeports dude

:/

I meant robs is supposed to be a big bridge aka monster/ J port (hence the discussion on other site about the need for one piece seal) and blitz had tuned it so they have the results that they could add to the table.

Quote from: matt p;846748Thought Marco was running full bridge :)

Yes I believe he is.

Quote from: colum;846747Do they???

Both are bridgeports dude

:/

Whens your RX8 drag car going to be revealed Colum? I hear its going to do Jap Drags Pro this year?

whaaaat? cat out the bag shocker! what porting yo running though?

We are running a Perfect Port.

Quote from: HaywardRotary;846786We are running a Perfect Port.

hahahahahaa what comp rotors?

Just out of interest when you say Stock ports make the best power band? Do you mean stock port (with stock Runners etc) or the Stock Timing? Because there is a Big Difference in the right hands?

Carl if you do enough digging you\'ll find out what I\'m doing, it\'s not hard to find, there will be no big reveal, it\'s done when its done, no rush, nothing secret, chassis has to have a lot more work done until I\'m happy with it.

Quote from: colum;846797Carl if you do enough digging you\'ll find out what I\'m doing, it\'s not hard to find, there will be no big reveal, it\'s done when its done, no rush, nothing secret, chassis has to have a lot more work done until I\'m happy with it.

Dindt have to do any digging Colum,Thats great that you are doing this, should be awesome when done. It ran a mid 9 with Geff on the 20b so what is your setup?

Quote from: Grant Monkhouse;846787hahahahahaa what comp rotors?

lower than most.

Quote from: HaywardRotary;846803lower than most.

Carl, how dose one go about knowing how much to remove to low the comp of a rotor?

for example say we had a 9:1 how would you know how much to take out to make it 8:1?

Quote from: Erdin;846804Carl, how dose one go about knowing how much to remove to low the comp of a rotor?

for example say we had a 9:1 how would you know how much to take out to make it 8:1?

I know it\'s not exactly the answer, but isn\'t it preferable to start with S4 rotors? Due to both the lower compression ratio and them being stronger, so will take additional milling with lower risk of weakening them too much?

Quote from: HaywardRotary;846803lower than most.

Quote from: marco;846807I know it\'s not exactly the answer, but isn\'t it preferable to start with S4 rotors? Due to both the lower compression ratio and them being stronger, so will take additional milling with lower risk of weakening them too much?

Hi Marco, I already have the s4 rotors in my car.

What i wanted to know was the principles of deigning the rotor to a certain compression spec, to see what is involved. if indeed there is such a thing? for example, say its a 13:1 rotor and i want to mill it to 9:1 how do you measure or know how much to remove?

Sorry, wasn\'t meant to sound condescending, just thought it was worth putting it down.

Simple answer is cut a rotor up and find out what you have to play with then it\'s some simple maths

I had a go at lowering cr of rew rotors

(http://i47.photobucket.com/albums/f170/mx1311/IMG_0013-1.jpg)

Carl, if the car goes faster than it did ill be happy, auto box is still for sale if anyone wants it?

*plug*

I\'ve now got a liberty for it :)

Quote from: colum;846839Simple answer is cut a rotor up and find out what you have to play with then it\'s some simple maths
 
I had a go at lowering cr of rew rotors
 
(http://i47.photobucket.com/albums/f170/mx1311/IMG_0013-1.jpg)
 
Carl, if the car goes faster than it did ill be happy, auto box is still for sale if anyone wants it?
 
*plug*
 
I\'ve now got a liberty for it :)

did the results make up for the time you had to put in?

whats the simple maths involved?

Nice pic of a scalloped rotor here, still trying to find the calcs at the mo.

http://www.rx7club.com/1st-generation-specific-1979-1985-18/1st-gen-13b-rew-redo-715412/

I\'ll be surprised if anybody lets there rotor trimming secrets out.

Quote from: matt p;846899Nice pic of a scalloped rotor here, still trying to find the calcs at the mo.

http://www.rx7club.com/1st-generation-specific-1979-1985-18/1st-gen-13b-rew-redo-715412/

They look soo sexy. I want :D




...As an ornament :P