with a bridgeported 3rd gen with a hks to4r would 500 rwhp below 20 psi be achievable if tuned correctly ?? if not why not ??
rgds
I would say yes it is possable, i dont know if it is possable in the UK but it has been done.
http://velocity.isfaster.com/new/rides/soul/main.htm
I belive Alf ran 24psi on a Half Bridge to achive 520rwhp but he ran into major problems when he went to the next stage (full bridge) as the Turbo was ristricting the engine causing it to fail. He then went to a T51 Kia on a Full bridge but never got it Running 100% (It blew up i belive at 610rwhp).
But you have to remember all this was done in Japan so they have the Experiance and Knolage to build and set somthing like this up.
He was in the Air force so when the Gulf kicked off it put an end to his stay in Japan so it never got finished.
Chris
Mmmmm 520rwbhp on a fc lump at 24psi
sounds promising. Hi Chris the car is already bridgeported and has hks to4r etc imported from Japan. Just trying to get an idea of what to expect from it for when it goes on the rolling road.
I have read that the to4r efficency range is approx 18 psi so was wondering basically if running at this psi 500rwhp would be achievable ona bridge not sure if a half or full bridge though. Some nice clips on that site shame they did not run for longer.
rgds
Ok, I did\'nt relise you had bought it built.
There is no easy way of finding out if its a Full or half Bridge, Unless you know what one sounds like? The half bridge is quiter (as tought that makes much diffrence if it has a big exhaust and you\'ve not heard one before)
Depending on size of bridge, Exhaust housing size etc you should see 500bhp at 18psi but it will more likely be at the Flywheel you may need to run a bit more boost to see that at the wheels.
I am sure you will have fun finding out why people love Bridges when they are hard to drive and drink alot of fuel as you leave 200 yard black lines down the road in forth gear ;)
Chris
http://www.teamfc3s.org/forum/showthread.php?s=&threadid=20300
Don\'t forget
1. RWHP is a completely meanginless measurement unless you are just after some delta measurements for changes you are making to your car.
2. Be careful of american power claims. They mainly use a dynojet which measures up to 18% higher than a \'proper\' set of rollers.
But back on the question. With a perfectly efficient turbo and intercooler 14PSI will double the NA power 18PSI will be 2.3 times, so to get 500 at the flywheel would need it to be 217NA HP, which is just believable with a stock inlet.
Oh and your power assisted brakes won\'t work anymore unless you have a seperate pump.
BIll
Good point about the brakes bill.
There are ways and means but you are right the efficancy will be Reduced.
You can fit a Vacume assist Canister that will help.
There is a lot of Powerfull cars out there i thought the US one was a good example of what you can do on a Buget.
At the end of the Day 90% is down to how well the car is set up, if its been played with by Muppets you\'ll be lucky to see stock figures from it?
Chris
Hi Carl,
What do you think on this?
I have been told it\'s a full bridge but whether it\'s full or half my main question is with the car being well tuned is 500bhp at the wheels anywhere near realistic in your opinion at 20 psi?
I am not asking the question so I can then lay claim the car has 500bhp at the wheels or anything, I just don\'t know enough about bridgeports and there potential in terms of big bhp.
Thanks in advance
Bit of an idiotic question here but was is half bridge and full bridge. I know I\'m stupid but what can you do. . . . . :confused:
You can see basic descriptions of the various port jobs here:rotary porting (http://www.badrotor.co.nz/technical1.htm)
A bridge-port achieves a very large inlet port size by breaking out toward the edge of the side housing (see how much closer to the coolant passages the edge of the bridge port is compared to a stock or extend port), retaining a thin \'bridge\' over the middle of the port for the rotor corner seals to pass over (without the bridge the corner seals would fall out of the rotors and drop into the intake port - bad thing!).
A 13B-REW engine has four intake ports; the smaller primaries in the intermediate plate and a secondary in each of the front and rear plates. A half bridge port only has two of the four ports bridge ported, a full bridge port has all four ports bridged.
HTH.
If you havent seen an engine without its gubbins removed then the following pic shows the intake ports (green arrows are the (very!) rough flow of the intake charge into the rotor housings) marked P for primaries (in the intermediate housing) and S for secondary\'s (one each in the front and rear housings) :)
The pink arrows denote the hardened faces of the rotor side housings that you can see various ports chopped into in the link in the previous post which shows the various port types...
HTH.
QuoteOriginally posted by BNA_ELLIS
Hi Carl,
What do you think on this?
I have been told it\'s a full bridge but whether it\'s full or half my main question is with the car being well tuned is 500bhp at the wheels anywhere near realistic in your opinion at 20 psi?
I am not asking the question so I can then lay claim the car has 500bhp at the wheels or anything, I just don\'t know enough about bridgeports and there potential in terms of big bhp.
Thanks in advance
Hi Brian,
I think that if you are running around 20 psi then the turbo will heat up the intake charge a fair bit so you could say that you may have around 2 times the volume of air going into the engine as if it was naturally aspirated with a cooler intake charge.(This is inspite of running over 1 bar)
On this basis I would say that with the fact that probably with the full bridgeport the engine could be running around 250 FLYWHEEL hp naturally aspirated that 500 FLYWHEEL hp is possible,but not 500 REAR WHEEL hp which would be approximately 590 FLYWHEEL hp.
If the engine is half bridge port then say around 450 flywheel hp.
I would strongly suggest that you carefully check the A/F ratio on this car as it may well be running close to lean,use a good fuel like Cool blue from 76,it is 106 octane,Clive can supply it.Bear in mind the higher octane available in Japan.
This would give you some margin on the rollers with regard to knock.
When you get your results please let us know.
One thing to allways bear in mind though is that rolling road figures are not accurate in terms of saying how much power anyone really has,they are just useful if you go back to the same ones each time to see if you have made improvements.Rolling roads can vary from each other by as much as 20% so just use it as a guide.
Kind regards
Carl
BTW I forgot to mention that we are talking of your specific turbo here as a bigger turbo may not heat the intake charge as much at 20 psi.
Kind regards
Carl
Thanks Carl,
It would be nice to strip the engine see how the bridge has been done in Japan and get Tim to copy another one for me. After driving it I am really tempted to have a bridge ported engine built.
A triple rotor bridgeport sounds very tempting with a nice turbo charger to help things along.:D
Should be good for single figures - mpg I mean! A lot of the single turbo 20B\'s running not much greater than stock porting make <10mpg as it is. Dont here of many bridgeport 20B turbos either - either big extend ports or PP\'d it seems - not sure why. Perhaps 3rotor BP\'s experience intake \'issues\' like some PP turbos are meant to???
Bri, Geffs 1/2 BP was a lovely drive - until you get around town obviuosly. The most annoying things about them is as Chris has menitoned - driving them off load/light throttle - they dont like it much. Geff\'s bucked about quite badly at times when trying to cruise - you find your self doing a lot of shifting, slowing down, accelerating etc in order to keep them on load...
Hi Rich,
I don\'t want one for a daily driver, just as a company show car
and hopefully a skyline whipping machine at next years santapod event:D
Yeah, I realise its not for a daily driver :)
They are fine to drive - you just have to keep in the throttle to keep them happy!
Skyline whipping machine? a \'bit\' of work required there I\'m afraid. They were running low 10\'s this year so will no doubt be in the 9\'s next year. Even with slicks thats going to need SERIOUS engine and drivetrain mods to get any where near in an FD... :(
A 500ATW FD in full trim on slicks would pull...well significantly more than 9.5s!
R.
I think were at least Two years behind the skylines, give it a little time for development and a bit of Knolage to be obtained and who knows?
Chris
Absolutely Chris. We need to be patient whilst the technical knowledge base grows over here. One day we will get there. It will cost plenty of motors - and people will come and go in the mean time, BUT - ONE DAY - The Rotary will be doing the butt-kicking at the strip in the UK - and I know a good few of us here will still be there to see it :)
Oooo, I\'ve come over all emotional
:D
Interesting read in Banzai this month Ralph Friend @ Costom Groundzero [name sucks!] is claiming 650rwhp @30psi!! on a T72 interesting that he has used datalogic and done a 4 way ignition map - mind you he is running on 106 octain:bandit Only in the US of A a?
Did some sums on the turbo calculator at //www.not2fast.wryday.com that my mate Eric wrote. Basically it confirmed what Carl was saying that you need a motor that will do about 250HP in NA form to get 500 at 18-20PSI.
Now just think about that a while. Ever seen 250HP off a stock inlet manifold? Now generally these things are not seen as a problem by the turbo crowd as you just add more boost, but we are talking about low boost levels compared to sierra cosworths, skylines and the like. With a rotary you have to play by slightly different rules and build the best NA setup you can then add boost.
The downside of this is that you can end up with the worst that a large overlap high revving engine and a turbo can give. After all a bridge or PP turbo goes against most of the rules. ( it shouldn\'t work but I have some ideas why it does.)
Now there is no reason that a good street port the right inlet and a properly designed exhaust shouldn\'t give around the 230HP mark after some considerable optimisation. This with 18PSI should be around the 460HP mark whilst still being a very well behaved car on the road.
Problem is the right inlet........
I don\'t think all bridges run that rough Rich I seen and heard Geffs, I know that does, My mate Erdin has a half bridge which runs well rough which I have also driven in . I believe both of these cars idle at 1,600 rpm and as you say when they are driven or tried to be driven normally they buck like a bucking bronco.
When my one is warmed up it idles at 1,100 rpm the idle is also quite smooth it does not fluctuate by much I don\'t get the bucking what I experienced in Erdins either. I don\'t know if this is to do with the tuning or how of the actual bridge itself?
Well I went down to rxmotors yesterday and was doing some tuning on this beast had the boost turned down to only .8 bar
This car is an absolute bullet still need some more work on the fuelling as when we get into the high rpm with foot to the floor
air/fuel ratio is below 10 and it gets a bit choked but it started getting a bit too late to finish off yesterday but. once power is applied it does not run leaner than 12.5 but needs leaning out a bit in the higher rpm and boost range. I am temtped to keep it for myself again, How about we up the stakes on the first car to do sub 12sec 1/4 :D then I\'ll sell it after:D
Car is laggy, but depends on what gear your in how bad it is. In 3rd gear at approx 30-40 mph you can floor it and nothing happens for a while then the car just goes mental. but going up thorugh the gears it\'s not too laggy. It\'s hard to tell what rpm the turbo is really on song as when it kicks you\'s have to be some kind of nut to take your eyes off the road. Can\'t wait to whack the boost up to what 18 psi but is a little too damp at the mo for that. Will keep all updated on progress.
rgds
Whatever bridge you have there will be a degree of self-EGR going on as the inlet never closes. In a weber equipeed car you also have reversion to deal with, which is not an issue if you have seperate primary and secondary throttles.
There is no real away around this unless you start doing things with 6-port side plates.