Originally Posted by
ashtonsser 
Its crazy cuz i can remember back in the day when log mani's were the shi$, mainly because noone really had any decent tubulars out yet, haha. No tubular is the way to go. With my T28 setup on a rwd tubular mani the turbo spool and power was soo much better than a buddies with a stock det manifold. But either way i went with a log mani for now being i got it with the whole kit for cheap.
If it doesnt make the power i want and causes problems ill look right away into getting a nice tubular mani for one to be safe on the motor and make the power i want safely. Protech's work is second to basicly none. His mani's are awesome, now if only we could get him to make us some n/a race headers. Im sure if he can do mani's like that for turbo how hard would it be for him to do a nice full out race header, big primaries. 3" collector, 3" all the way after. Wonder if thats ever been brought up to him at all.
Neways ill see what happens and if im not happy then ill ditch the log mani. But again for the power i want to make i think i can hit my mark and still be well within a large safety margin. Ill probably just take out some overlap on the cams, im thinking -5,+5 or so on the stock 20ve cams will do the trick and help with the issue on that.
if there is enough oil pressure at idle and can keep the high ex cam on at idle then you can take out 20deg of overlap as shown in the other thread i posted in with the 20ve cams degree card.
Originally Posted by
mrslappy ca18 bluebird, Is there a reason why you are running such short runners with that turbo manifold? You are loosing all the power gain from the resonance of the tuned runner length. You are letting the pressure wave from the intake valve closing leave the intake runner. this will cause a very poor cylinder fill when in the large cam lobe. A forced induction and N/A motor both use the same Tuned length resonance to help cylinder fill and take advantage of overlap scavenging. This does not change with boost. You may possibly gain overall flow by loosing the runner length because of the manifold design and thus will help cylinder fill, but you are actually loosing power and most likely spool in the midrange. I see a lot of Turbo people, Honda, Nissan, toyota do the cut-off, short runner intake manifolds because they think they are making a huge gain in power, but in reality they are only gaining top end power and actually loosing more everywhere else. I'm not sure how fast you are building boost but a GT30R .63 housing on a properly setup engine should make 1bar boost and 300lb ft TQ by 4000-4200rpm no problem. I have seen a lot of setups ( all makes here) with a .63 GT30R spool very late, closer to 5000rpm or later because of parts on their motor that they "think" is making more power but it is not. Many people just bolt parts onto their motor thinking its the best setup.
the 3 highest HP DET/VET setups I have seen all used factory Intake manifolds. Ported, reworked or indifferent, these motors all made 600+whp and 450+tq at "low" boost levels. 2 of these motors actually made more power than similar K/B series honda setups with similar parts, same turbo and displacement.
ok i assume you are talking about the intake manifold pictured in that link i posted. Now that car is not mine. That manifold from memory actually has a bit more length extended to the runners inside the plenum space via velocity stacks....i think, i could be wrong though. But still from memory he did it that way because of the reverse taper of the standard ve runners.
I am also a big fan of the standard manifold on the det, in fact an extrude honed det intake manifold does perform very well.
However in saying this i also went quite short runners on my rwd vet. Only added about an inch from the stock lower manifold, and am also using quite a large plenum. I dont think i will loose top end, but am a little concerned about loosing spool and possible midrange.
you mentioned you dont know how quick the guy is producing spool on this set up, well i can tell you its **** fast (mind you it is a 2.2l), i was very surprised, from memory it was below 4k, and i remember a he had a fair bit of boost by 2500rpm
for my set up i will not be using a 3076, but the turbonetics ceramic ball bearing 76mm 50trim compressor with the 65mm in and 57mm ex 10 bladed turbine wheel with a .63 housing. A though not my first choice for a turbo i still like it better than the 3076r as compressor surge is much better. I would rather run a compressor that doesnt surge in the first place than run the anti surge housing that does consume power anyway.
first choice would have been a billet s56gt3 with a divided .78. It basically runs a borg warner extended tip 50 trim compressor with a inconal 65 in 56.6 ex 10 balded design based of the gt wheel, all in a duel ceramic ball bearing center, which is much lighter and debatably stronger than the garret center. It has all the best of garret combined with all the best of the new borg warner series. This sucker would have cost me 1k more than my current choice though. However i am surprised more yank dont jump on these why our dollar is down, will be comparably priced to a garret unit.
Originally Posted by
mrslappy That shorty turbo manifold is very nice. Simple, compact and individual flow which is much better than a log. If that manifold is $600 then thats a steal for what you get. The only thing i'd dislike about that is the Wastegate placement. Your best placement is for the Wastegate to dump the exhaust gasses in the same or similar direction as the exhaust flows into the turbine housing. I do understand though that the placement is because of fitment in the vehicle to clear the radiator and by seeing SE-Rawkus' dyno sheet, it seems very well that it works.
Coheed, stress from a lot of boost and stress from higher RPMs are 2 different things. making 450whp from 24psi means you are retaining a lot more heat in the motor than say 500whp at 15psi because of backpressure and not being able to flow the gasses out. However, I do agree that with RPM's comes more stress and wear n' tear but there are a lot of factors that can effect that. The largest factor ofcourse is piston speed. a 200whp sr16ve motor at 10,500rpm will last longer than a 8,500rpm SR20VE motor because of piston speed, R/S ratio, Friction on the reciprocating assembly and on the crank, and the smaller motor is going to produce less heat than the larger one for the same power output. RPMS do stress the Rods more than boost will, that is why a Honda K20 motor ( mainly the early ones) will break the rods in half if mis shifted above say 9500-9800rpms for the early motors but they will take 20psi boost no problem if you keep the rev's below 8000rpms. I"m not sure how long it will take that abuse but they do for short periods of time.
Coheed, I think if you get even one of those shorty turbo manifolds as SE-Rawkus used and spend some time on the dyno dialing your cams in you should see close to 500whp no problem at the same or less boost.
SE-Rawkus and Coheed, you should try a .82 divided T3 turbine housing turbo setup. If you build it out of the 1 1/4" Schedule 10 pipe, you will have a very very nice power band, Divided turbine housings work very well.
Back to the NA topic, I do want to get more into the development of the sr20ve motor more as the honda and toyota stuff is getting kinda boring... same parts, same motors same stuff nothing super cool... I think that some of you should do some 2.3-2.4L motor builds and get some good solid head work done and have it all ready for some big cams when they finally come out. I was pointed to a company called mazworx and i see they have a nice head gasket that looks very strong similar to the Greddy and Apex ones. There are also some simple easy piston and con rod tweaks you can do to make a lot more power instead of just cams and port work.
Generally a set of custom one off set made pistons for $700 can make as much as 10-20whp over a set of "shelf" pistons.
-Ted
i am keen to here more on this? what tweeks do you refer to?
i am running 8.5 det pistons so my comp will be between 9.1-9.3 depending on what gasket i use. i will also be running bc billet rods, allthough slightly heavier than the eagles they are much more robust with great oiling to the little end
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