Jump to content
SAU Community

Recommended Posts

I can't believe that there aren't gains available from larger cams...call me crazy, but here are the factory specs:

BNR32 RB26DETT Solid

Intake duration 240°

Exhaust duration 236°

Intake lift 8.58

Exhaust lift 8.28

Preset valve timing INTAKE 113°

Preset valve timing EXHAUST 125°

And here are some Tomei "drop-in" examples:

Type A

Intake duration 260

Exhaust duration 252

Intake lift 9.15

Exhaust lift 9.15

Type B

Intake duration 260 (same intake as type A)

Exhaust duration 260

Intake lift 9.15

Exhaust lift 9.15

* Type A
Designed to best suit the stock & N1 turbos for optimum performance balance of low to mid range torque.
The Exhaust cams duration was reduced to maintain best idling.
* Type B
By extending the duration timing compared to the Type A Poncams, both response and peak power was raised and these camshafts best compliment the mid to large size turbo charged applications.

How can one say that they won't make more horsepower with more duaration and lift? surely this is a myth?! Perhaps the gains aren't there with some turbo / valvetrain setups, but I assure you there will be a powerband difference between STOCK, A and B in nothing more than lift alone.

Now, does everyone have the mods to support the flow / overlap? Who knows.

My experience with streetcars with turbos and cams, stay on the small side of duration. I chose Poncam A's for my 2.75L stroker motor with ported head, +0.5mm SS valves, retainers, springs, etc. Just wanted a touch more duration and lift than factory. I won't be able to tell you what they do different, but then again, I'm pretty extreme on setup with BW 8374EFR turbo and all.

Edited by HarrisRacing
Link to comment
https://www.sau.com.au/forums/topic/456095-cam-choice/#findComment-7523314
Share on other sites

Change the cams when you change the capacity of the engine or you are going for a hell of a lot more power then the -9 will ever make

R34 brembos can be made to fit you just need to drill out the holes on the r32 front hub so that the bolts fit thru

Link to comment
https://www.sau.com.au/forums/topic/456095-cam-choice/#findComment-7523316
Share on other sites

You are right there will be a power band difference it all move to the left and causes the car to drive worse then it needs to for the power they give, the other issue with all these "drop in" cams is they never have enough lift for the increased duration, which causes them to lower dynamic compression even more then a properly designed cam shaft

We have made the mistakes of using all these parts and know first hand what their benefits/flaws are, a lot of people get caught up in the fact they fitted these pieces of junk and made 5-10kw but forget they lost 20kw out of the bottom end of the rev range where you spend most of your time actually driving the car

Link to comment
https://www.sau.com.au/forums/topic/456095-cam-choice/#findComment-7523317
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • It would be well worth deciding where you want to go and what you care about. Reliability of everything in a 34 drops MASSIVELY above the 300kw mark. Keeping everything going great at beyond that value will cost ten times the $. Clutches become shit, gearboxes (and engines/bottom ends) become consumable, traction becomes crap. The good news is looking legalish/actually being legal is slighly under the 300kw mark. I would make the assumption you want to ditch the stock plenum too and want to go a front facing unit of some description due to the cross flow. Do the bends on a return flow hurt? Not really. A couple of bends do make a difference but not nearly as much in a forced induction situation. Add 1psi of boost to overcome it. Nobody has ever gone and done a track session monitoring IAT then done a different session on a different intercooler and monitored IAT to see the difference here. All of the benefits here are likely in the "My engine is a forged consumable that I drive once a year because it needs a rebuild every year which takes 9 months of the year to complete" territory. It would be well worth deciding where you want to go and what you care about with this car.
    • By "reverse flow", do you mean "return flow"? Being the IC having a return pipe back behind the bumper reo, or similar? If so... I am currently making ~250 rwkW on a Neo at ~17-18 psi. With a return flow. There's nothing to indicate that it is costing me a lot of power at this level, and I would be surprised if I could not push it harder. True, I have not measured pressure drop across it or IAT changes, but the car does not seem upset about it in any way. I won't be bothering to look into it unless it starts giving trouble or doesn't respond to boost increases when I next put it on the dyno. FWIW, it was tuned with the boost controller off, so achieving ~15-16 psi on the wastegate spring alone, and it is noticeably quicker with the boost controller on and yielding a couple of extra pounds. Hence why I think it is doing OK. So, no, I would not arbitrarily say that return flows are restrictive. Yes, they are certainly restrictive if you're aiming for higher power levels. But I also think that the happy place for a street car is <300 rwkW anyway, so I'm not going to be aiming for power levels that would require me to change the inlet pipework. My car looks very stock, even though everything is different. The turbo and inlet pipes all look stock and run in the stock locations, The airbox looks stock (apart from the inlet being opened up). The turbo looks stock, because it's in the stock location, is the stock housings and can't really be seen anyway. It makes enough power to be good to drive, but won't raise eyebrows if I ever f**k up enough for the cops to lift the bonnet.
    • There is a guy who said he can weld me piping without having to cut chassis, maybe I do that ? Or do I just go reverse flow but isn’t reverse flow very limited once again? 
    • I haven’t yet cut the chassis, maybe I switch to a reverse flow. I’ve got the Intercooler mounted as I already had it but not cut yet. Might have to speak to an engineer 
    • Yes that’s another issue, I always have a front mount, plus will be turbo plus intake will big hasstle. I’ve been told if it looks stock they’re fine with it by a couple others who have done it ahahaha.    I know @Kinkstaah said the stock gtt airbox is limiting but I might just have to do that to avoid a defect so it atleast looks legit. Or an enclosed pod so it’s hidden away and feed air from the snorkel and below Intercooler holes like kinstaah mentioned. Hmm what to do 
×
×
  • Create New...