To Port or not to port!!

[PGiljevic]

I have decided i dont like the power band of my large street port.
 
I think im going to have one set of my standard plates port polished to a mirror finish and have just the closing edge of the secondary ports opened up 1mm and leave the exhaust housings opened/ported as they are and see how it goes back on the ,81 hotside. (thoughts on this?) I think this will be better on the street and out of the corners on the track.
 
im at Anglesey race track with my mid ported engine in 4 weeks. If the track is dry ill be able to have a proper comparison of ported to non ported on the same turbo and make my mind up on the way forward.
 
I think id also like some EGT data on my car/tune so i might buy the kit to monitor this.

Yep see how you go, make sure you remap the engine, as the std or near std ports will need far less fuel after 6500rpm there are also timing changes you can make to keep the power band high like I have in my car (making peak power at 7400rpm and allowing the engine to rev to 8500rpm) for maximum flat power band) which is what will net you the acceleration increases and power curves like the one I posted.

The big benefit of the std porting in the chamber filling at mid range rpm\'s the maximum torque you can make at 4500rpm, earlier turbo spooling. Ironically the smaller/std ports allow you to use a much larger turbine housing! and you gain even more power as a result *but I don\'t want to give away all my secrets* :Hammer Suffice to say you don\'t need a small turbine like most preach to pick up the response and power, cause you have no problems with chamber filling due to molested port timing that only provides benefits over the narrowest and highest rpm range.

Std porting free\'s you up of many rotary engine constrictions like back pressure sensitivity and turbine size? how? just do a compression test on your engine to see how, any ported versions register far lower compression than the stock std one, cause they are inefficient at chamber filling and only work over a narrow rpm range which totally does not suit sports driving or most track situations.

All I can do is but share my experience, and if others find it interesting and of use then good. When you can make high power and have broadest power range and still top 200+mph in a stock geared FD, and have it quiet and efficient you gotta question why you even need to port the engine block at all. I first found this out many years before I met Tom (pp13B\'s car) when doing a budget rebuild on a mates car at 3am! we just assembled the stock block back with a spare rotor housing and new Mazda seals, and the car was sold to another customer and fully develped with a new turbo, water injection, CDI\'s etc etc and it had the best power band of any car around, stupidly fast very high power (300+rwkw) went for almost 10 years *the car was actually stollen!!! so it could still be running for all we know lol :god Even the bloke who owned it (he was a rotary engine builder himself) said to me I want you to build me next engine!@ and I told him it was totally stock std, just a fresh rebuild, even two different tuners who redid other ECU instals in it over the years commented on how instant the power is and it was the best rotary turbo they had driven .................. the secret was to not molest the port timing :rollin

I remembered all of these early experiences and decided to test it analytically myself in my own car, and I can now see why porting on the 13B-REW is totally 100% not necessary. I was concerned that top end power would not be acceptable, but as the say proof is better than talk and I proved that is not an issue at all. For a road car I would never suggest porting again even though I make great money off it as a service. Try it for yourself, if you are objective about it you will come to the same conclusion as most others who have gone from one extreme to the other on this topic.

[PGiljevic]

Add further to this *at extreme end* :guinness

In my world you hear of people saying "oh well but the ports are are a restriction! to high power!"

I have people who have run 8\'s at over 170mph in drag cars on 100% std 13B-REW motors out of a Mazda carton box. And only been limited by their fear to push harder. So no restriction there :WaveBye

I can list many examples of people running unbelievable times and terminal speeds (in drug world) on 100% stock std 13B-REW engines, using in some cases turbo\'s that are bigger than a wind power generator! stuff that would make you question why anyone would ever get out a die grinder. And not one hit wonders either, engines that have done duty in road cars or been bought from parts wreckers and installed and run for years! others who have found this out by simple mistake after the million dollar race engine sh7t itself and either obtained a Mazda reman block or put in a slapper stock version with no porting no meda dollar doweling no molested compression ratio bullsh7t and done as good as they ever had before. Some of those same people just refuse to waste money on bridge porting or stud kit machining cause they worked out its a basic con job of the highest order, totally not necessary for what they are doing, and remember we are talking very fast here, not internet racers.

I have friends all over the world and one the other month got a engine refresh job on a car the was imported the (8 second drag car) from a well know rip off joint! he could not believe what he saw when he pulled it apart! 100% stock std engine, Mazda 2mm seals, ports 100% stock (minus the die grinder runs across the end plates where they tried to debur some edges LOL!!!) exahsut ports not touched at all. Sold to the importer as a "mega dollar race engine" :rollin it ran in that country for a long time at the same performacne level and they thought it a good idea to rebuild the engine for a new race year.

Seen it, done it, experienced it.

[antnicuk]

Pete,


What are your thoughts on just porting the exhaust ports a little and leaving the intake ports alone?
Any benefits or downsides?

some very valid points made but what about just the exhaust ports though?

[skybusr34]

interesting thread

[PGiljevic]

some very valid points made but what about just the exhaust ports though?

I\'ve made em as big as Jordan\'s anal passage and everything in between, it probably is the worst thing you can do to them is lower the opening edge, best way to make the rotary even more inefficient (wasted energy in the power stroke and kills turbine egt\'s).

I\'ll try to scan some pics of all the different styles trialed over time, even Peter Andre would be impressed with the molested passages :Ladys-man

[PGiljevic]

It\'s much better time spent on leaving the engine alone and concentrating on the turbocharger and other system parts and working them to allow you to "man up" and use proper levels of boost, thsi will derive far higher gains in power than any molestation with a die grinder :rollin and you will have much more mid range power.

Life begins at ~1.5 bar or 20+psi, want more power? run more boost :Hammer

One of my favorite cars of all time is here > http://www.fastestcosworth.com/
206+mph on a GT40 turbo @ 36psi (~700bhp) and tough as f7ck! quiet, drivable, smooth idle, a rotary owner could learn a thing or two from these people. The latest donk ~840bhp 2.15lt, 7500rpm 41psi on GT42RS and boost alone, great power band too!.... totally amazing car.

[Grant Monkhouse]

It\'s much better time spent on leaving the engine alone and concentrating on the turbocharger and other system parts and working them to allow you to "man up" and use proper levels of boost, thsi will derive far higher gains in power than any molestation with a die grinder :rollin and you will have much more mid range power.
 
Life begins at ~1.5 bar or 20+psi, want more power? run more boost :Hammer
 
One of my favorite cars of all time is here > http://www.fastestcosworth.com/
206+mph on a GT40 turbo @ 36psi (~700bhp) and tough as f7ck! quiet, drivable, smooth idle, a rotary owner could learn a thing or two from these people. The latest donk ~840bhp 2.15lt, 7500rpm 41psi on GT42RS and boost alone, great power band too!.... totally amazing car.

Hi Peter, i have just read the wi articles on your website, really interesting stuff and shows a thing or two about paying attention to history. There are a few things i didnt understand with the numbers used for afr and water/fuel ratios but with more researching im sure i will.
 
Have you experienced anything with the water saturation into the engine oil when using too much water?
 
i am really looking forward to getting into the mapping on my brother FD, hopefully i will get him to keep the standard ports (after telling him about all different ports and the power acheiveable) and run a single turbo with wi and boost the hell out of it!

[Grant Monkhouse]

I think that people choose to port engines due to the fact that the information they gather doesnt explain the total some of the moification to an engine that is required to gain the most out of porting.
 
porting an engine moves the power band further up therev range, so to better gain the HP from the higher power band would mean revving the engine higher and higher?
 
When i first learnt about porting i thought that my engine would be able to rev up to and beyond 9,000 RPM. this is not the case. to get these kind of RPMs further modification to things as the rotors amongst other things must be done?
 
I dont know a huge amount but this is my understanding of porting on a rotary, anyones input into where i am going wrong would be good.

[DR SCHNITZEL]

Rice great info i am just confused about one thing. Am i reading right that an engine builder asked you to build another stock block for him and it took you to build him a stock block for him to realise that was the way to go? or do you mean he wanted you to do your magic with turbo and WI/tuning again?
 
Will having my exhaust port opening 2mm lower really make much of a difference to power? how much 5% 1% 2%. Will it just make power and tourque before 6500 rpm plus worse?
 
what about a stock block but just with lightened rotors and what do you think of the huge single butterfly throttle body? surely there is something more optimum than the stock block with stock ports for overall great trackability driveablity?
 
i dont understand what you are saying about running the larger turbine housing on stock ports. If i go back to standard ports surely i should go back down from the 1.30 hotside to the .81 or i will lose alot of mid range/spool? i do understand the egts will be a fair bit higher. I currently am not running AI as im not running more than 1.1 bar.

[PGiljevic]

Rice great info i am just confused about one thing. Am i reading right that an engine builder asked you to build another stock block for him and it took you to build him a stock block for him to realise that was the way to go? or do you mean he wanted you to do your magic with turbo and WI/tuning again?
 
Will having my exhaust port opening 2mm lower really make much of a difference to power? how much 5% 1% 2%. Will it just make power and tourque before 6500 rpm plus worse?
 
what about a stock block but just with lightened rotors and what do you think of the huge single butterfly throttle body? surely there is something more optimum than the stock block with stock ports for overall great trackability driveablity?
 
i dont understand what you are saying about running the larger turbine housing on stock ports. If i go back to standard ports surely i should go back down from the 1.30 hotside to the .81 or i will lose alot of mid range/spool? i do understand the egts will be a fair bit higher. I currently am not running AI as im not running more than 1.1 bar.

You will have *allot more* mid range spool and power on a stock ported engine V\'s any level of street porting, and thus you can run a larger turbo and pick up mechanical efficiency due to less pumping losses on the exhaust stroke.

I have experimented with single butter fly they do nothing of benefit but they do make it a nightmare and very rough due to low air speed at low rpm, the slightly staged factory set up is designed the way it is for a reason and its the best, it poses no meaningful restriction to the engine.

Any porting you do down increases the EGT as its allowing un utilized mixture out the the engine and into the turbine, its wasted energy, you loose mid range torque when you do this. leave the lower edge of the exhaust ports alone, and only clean it up if you must, take off a minimal amount. You will see on my site under the engine page an article from 1997 of the old AN&L Rx7 where there are detailed pics of exhaust ports there and others talking about it.

With the story it took my engine builder friend to actually own his own car *engine built by me* to realize just how good a stock port is *no porting necessary* hell it even took me till now instrumenting all my own car to see just how good a stock port is. I have a great example comparing another very fast car to mine (look up DOCMAR RX7 on youtube) its a GT47 street ported cosmo block FD RX7, running open waste gate, massive exhaust, 1.7 bar boost! (564PS @ 7430rpm and 54kg/cm torque at 5960rpm) and they VBOX tested it (you can find the car review in Greek and translate it) 60-200kmh is 9.09 seconds (mine is 10.08 seconds) terminal speed\'s are within 2mph of each other over 400m. And I only run 1.45bar boost (~485bhp), a full catalytic exhaust, plumb back legal waste gate. I\'ll put up a video of mine on 1.7bar and VBOX when I get a chance to do an offical test again to show that its easily matched and in a much nicer road car package.

[skybusr34]

fair plays mr riceracing.. you`ve really put the cat with the pigeons with all this non porting stuff. im very intregued..

thumbs up

[PGiljevic]

Hi Peter, i have just read the wi articles on your website, really interesting stuff and shows a thing or two about paying attention to history. There are a few things i didnt understand with the numbers used for afr and water/fuel ratios but with more researching im sure i will.
 
Have you experienced anything with the water saturation into the engine oil when using too much water?
 
i am really looking forward to getting into the mapping on my brother FD, hopefully i will get him to keep the standard ports (after telling him about all different ports and the power acheiveable) and run a single turbo with wi and boost the hell out of it!

FAR is simple to convert to AFR (something most relate too)
 
1/FAR
 
So
 
1/.1 (FAR) = 10.0:1 AFR
 
Water to fuel ratio\'s
 
0.2 = 20% water (v\'s fuel qty) we commonly use 20% to 60% by mass ratio\'s remember this is by mass NOT VOLUME!
 
Too much water simply can cause mis fire or low power for the given varibles you are running at. With my VBOX3i and self developed power measuring capacity I have the ability to fine tune and measure power each and everytime I drive the car in all gears and at all speeds on road, its been a big part in me being able to see what works in reality v\'s in an artifical dyno room. It\'s critical to be able to measure this sort of thing to get the balance right when developing WI and how much to use etc... especially when trying to make maximum power from what is esentially a stock std engine or parts and emissions legal set up too

[Mir]

Pete

lets suppose, If someone buys your Water Injection Kit, who is going to install it for us here in the UK?, as I have heard that "No one is competent enough to install your Water Injection Kit on the Rotary Engine"

Any suggestion

Syed

[PGiljevic]

Pete
 
lets suppose, If someone buys your Water Injection Kit, who is going to install it for us here in the UK?, as I have heard that "No one is competent enough to install your Water Injection Kit on the Rotary Engine"
 
Any suggestion
 
Syed

Dragon could do it easily. I am sure Howard could also.
Anyone mechanically minded with some access to basic fabrication could do that same as well.
So far as the tuning aspect or set up that is a non issue as all the knoweldge comes from me, you just follow the recipie, it\'s very straight forward from that aspect of things.
 
Any WI set up will work, I have a friend in Norway (Frode) who used a WI kit bought of E-Bay along with my set up advise givien over E-Mail and he managed 585bhp on his bosses engine dyno at VS Mottor. So long as you are in this trade and have some basic skills then its pretty easy really irrespective of what WI system you use. The tuning part is access to the knowledge (which you get when you buy my system) others you have to find it out for yourself or go to tuners who are proficient in it and have examples of cars runnning with it.
 
Local ones near you that come to mind are Wifbitz and Dragon using Aquamist based systems.

[Mir]

Dragon could do it easily. I am sure Howard could also.
Anyone mechanically minded with some access to basic fabrication could do that same as well.
So far as the tuning aspect or set up that is a non issue as all the knoweldge comes from me, you just follow the recipie, it\'s very straight forward from that aspect of things.
 
Any WI set up will work, I have a friend in Norway (Frode) who used a WI kit bought of E-Bay along with my set up advise givien over E-Mail and he managed 585bhp on his bosses engine dyno at VS Mottor. So long as you are in this trade and have some basic skills then its pretty easy really irrespective of what WI system you use. The tuning part is access to the knowledge (which you get when you buy my system) others you have to find it out for yourself or go to tuners who are proficient in it and have examples of cars runnning with it.
 
Local ones near you that come to mind are Wifbitz and Dragon using Aquamist based systems.

hi Pete,

Can u email me on gillanis@hotmail.com
need to know da price of the kit u sell ..
Regards
Syed