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Hey guys we are stumped we are building a hybrid RB25/30 what we basically wanna know is pon cams vs standard cams or even go to pro cams? your opinion what you are running etc etc?!? our goal is 550hp plan on running 98 and we hope to achieve this with a GT35/40 or similar... any input would be great, have goole searched and spoke to many different people basiclly every one is saying something different any input would be great... we have performance valve springs (brand name) and plan on running cam gears if need be. we also want to keep our engine responsive as we can... any help would be much appreciated : )

tas

Edited by tazzy
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If you want response on a 3L with that turbo, I wouldn't be going longer duration cams, if you can get something with similar duration but more lift, that would be the way to go.

Lift = power

Duration = when it makes that power

There are a couple of places over east (Camtech and Tighe?) that do custom regrinds, might be worth a look.

I'm running a Tighe grind in 30DET. No disagreement with Bubba, you need to not only have a power target (is that rwhp?) but also an idea of what rpm range and rpm ceiling you want the engine to operate.

Mine holds peak torque almost dead flat from 3400-7000 with hard cut limiter at 7200. Very driveable and predictable, I'm satisfied with it. Scavenging seems pretty effective, and it demands heaps of ignition timing. If you're into "tough" exhaust noises it's not bad there either, but is fairly fuel hungry.

I think that either stock cams or the Pon Cams might make higher peak torque number due to the benefit of VCT. But whether they hold that peak torque as long, or over what range might be different. My searching prior to building suggested a 30DET with stock cams seems to nose over just after 6000rpm, meaning the torque is falling off quickly at that point. That didn't suit my requirements, and found Tighe could supply something within my budget.

Turbo selection, manifolding and porting all play their part in the characteristics you end up with, not just a power number.

In talking with cam manufacturers suggest you talk to them about the use you want to put the car to, might be helpful.

Update us with progress in this area please

thnx heaps guys...

I will keep you all updated, going to keep looking into it... going to speak to Tighe next week also been told the stock rb26 cams are an option and also been told to not worry bout them all together and just keep the stock cam shafts, but taking it all on bored. The tomie pon cams... they would be the 256 with a 8 or 9.5? lift at highest with out having to upgrade the lifters if i remember correctly. we are aiming for 450RWHP will be mainly used for street and occasional drag "3400-7000" rpm range sounds good.. i think it might be the go... ill ask around and see what other people say feel free to throw in opinions. all much appreciated : )

tas

Not to disagree with Guilt-Toy, as he is very experienced and knows what he is talking about...

But on my RB30DET - I went from stock cams and 340rwhp (built auto with stall), to the Tomei pon-cams 256 and 8.5 lift (had them measured and yes its odd) and 400rwhp with 2psi less boost. Also ran 11.6 on street tyres (2.3 60 foot).

Best upgrade I've made :)

Edited by cactus

Its a built RB30 - GT35R (.82r), 6boost, 550cc, GReddy type intake, 80mm TB and the usual bits n pieces. Also didnt mention that we didnt bother playing with adjustable gears, so still set at 0 (possibly more power to pick up from this).

Response improved slightly, but the mid-range is where I saw massive gains. Makes stupid hp @ 5000rpm and was still making power at 7500rpm (didn't want to push any harder). Will try get a graph up later tonight.

256deg isn't far off factory duration, it's the extra LIFT that gave you more power at less boost which is the point I was trying to make above.

My other point about regrinds, is you give the guys your engine specs, turbo specs and intended use, they will then CUSTOM SPEC you a cam profile to suit YOUR setup.

Edited by bubba

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