HKS 280's over 272's on 2.3 stroker
 

Hi guys,
Could anyone tell me if by changing from the HKS 272's to the 280's a waste of money and time on my 2.3 stroker? Am currently putting out 512 ATW on a Dynojet at 30 psi rev limiting only to 7000 rpm ( C16 gas) and not putting anymore power. This is on a Greddy T67 turbo kit. Car goes great but was wondering if it'll be better on the 280's or its better to just leave it as it is? I suspect that the stock 8cm turbine housing is choking the motor above 6000 rpm. Am looking to make 550 ATW. Any inputs? :updown:

280 is must for big turbo!!!{offtopic} Are you rich???What your occupation?GTR,EVO VIII and EVO VI cost a ton of money!!

whats a 289?

if yyou meant 280..... hes refering to cams.

no he had 289 and changed it, I never heard of it before, never mind....

How bout some piper, jun, revolver?

higher lift baby~

yeah there are better cams out there than HKS, do a search....

switching HKS 272 - HKS 280s = waste of money
Switching HKS 272 - Tomei 280s, JUNS, Pipers = better use of money

Did you try TOMEI?!

Am I having a brain fart? As I understand it:

Longer duration cams offer more power at the higher end of the rpm band. With a stroker kit at 2.3L, your top end is 6,500rpm, 7k max, right? I'd go from the 272's to the 264's, so you get more at more of that area under the lower rpm part of the curve. With 272's, and even more so with 280's, you get a huge spike under the curve from 6,500 to 8k+, but you can't safely use that torque with a stroker kit.

True, bigger turbo's like longer duration cams, but what good are they if you can't get at the majority of the power, anyway? Plus, the reason one would go for longer duration cams with a big turbo is for better spool-up, right? Well, with that 2.3L stroker, you're already getting hella fast spool-up, much more so than long-duration cams can offer.

If I'm wrong, let me know, but my understanding of stroker kits, turbos and cams and their inter-relationships has recently been overhauled by someone I trust quite a bit, so I thought I'd pass it on.

which one would you say was the best?

Your thinking is correct, but properly tuned long duration cams with cam gears will make the same low end as 264's while retaining some of their top end benefits. Basically more power everywhere...

- Steve

That was what I thought and I went ahead with the 280's in the car now. With the cam gears set at -4 in/ -2 ex the car made the same wheel power except that it took out the power roll over above 6500 rpm but lost power everywhere below 4500 rpm where full boost is. ON the road impression, the lost in wheel power is definitely noticeble below 4500 rpm but above that for some reason the car seems to pull much harder and stays on longer althought the dyno doesn't tell so.... I sort of regret now as I should have tried either the Tomei 270's PRO cam or the JUN 272's which I thought must be similar to the HKS 272's I had anyway.... Someone was telling me that if you fine tune the cam gears further I may gain back some of the lost horsepower below 4500 rpm? Any cam gear settings suggestions here?

At -4/-2 with a set of HKS 280s, you're going in the wrong direction on two different accounts.

Do you have a means of tuning the car? If so, try +1/-1. That should change things a bit. There are settings that are even better, but I do not recommend them unless you have a VERY good means of tuning.

Am running an Autronic PnP and by using the HKS cam cards provided, ended at a point of 2 degrees advanced on the intake and 4 degrees advanced on the exhaust somehow. With some tuning, the car made only 485 ATW down from the HKS 272 before.. Mixtures were bog rich at that point so we had to lean it out. We then retarded the exhaust cam followed by the intake cam and the power went back to where it was before at 512 ATW but noticed that the bottom end lost close to 30 WHP on the spool up.

What do you suggest Ted?? Advance the intake by 1 and retard the exhaust by 1? IS that crank or cam degrees?