Max Power Seem On Stock Rb26 Cams

[MJTru]

I'm really thinking about not using my hks 272 cams. This is because I have always seem people complain about about cams cause a loss in power. These cams are 272 at stock lift or very close to it. My hp goal is around 600 hp. I got upgraded con rod bolts and piston pins. So if I want I could crank the boost a little bit more. So the very max would be around 750hp.

I'm about to shim the head for these hks cams but it's been like a day I'm stalling cause I do t know what to do.

My car is for drag racing but will see short drives in the streets.

Does any one have experience with cams that can help me out????

Edited May 25, 2014 by MJTru

[Piggaz]

What is your max RPM?

[MJTru]

I wouldn't want to go pass 9000 rpms. Does this have somthing to do with the duration. ???

[XRATED]

If it's drag racing mostly, then get some bigger cams..... Who cares what the engine is doing at 1000-5000rpm, all you need to worry about is a phat power curve at higher rpm.

[R31Nismoid]

^ agreed. If you don't need low-down, then just put something that will focus on the upper.

400rwkw have seen from stock 26 cams none the less, you can feel them sorta die off from 8000rpm though at least with -5s. Bigger turbo might alleviate that a bit too as well

[MJTru]

Well I was told that the cams a hks 272 but I'm not sure of the lift. I was told that it's stock but I have a caliber so does anyone know any methods I can use to measure the cam lobes and find the lift.

At the moment I've just done shimming the lifters for the the exhaust cam. Tomorrow I'll do the intake.

Please guys I need to understand if these cams will work for me. After I've finished the intake cam and my oil pan reaches from racefab. I should be good to install the motor.

[Ben C34]

With the calipers measure the cam lobe to the base circle.

Subtract the base circle diameter to give you the lift.

I have gone dumb and can't remember base circle at the moment.

[Piggaz]

With the calipers measure the cam lobe to the base circle.

Subtract the base circle diameter to give you the lift.

I have gone dumb and can't remember base circle at the moment.

If they're a "drop in" cam then the base will be 32 mm.

[GTSBoy]

Please guys I need to understand if these cams will work for me.

Of course they'll work. Given that your intention is racing then pushing the power band up in the revs a little won't hurt at all. The guys up above have already told you that you'll be fine.

There are plenty of people using 272 duration cams on motors making less power and driving exclusively on the street. They are the ones who have chosen the wrong cams, not so much you.

FWIW, you probably don't need cams that big. A little less duration and a little more lift would probably be smarter, but there's nothing wrong with what you have.

Edited May 28, 2014 by GTSBoy

[MJTru]

Hmm. This is nice to know. I don't plan on driving the car on the streets at least just to get it to the tracks as its only 5 minutes away from my house.

I can't remember but I think a long time ago I came across a formula using the centerline of the cam and dividing somthing to find the lift. I'll google it and post the formula up. Thanks guys for all the help. Well I had a feeling the cams would kill bottom end power. I had the whole bottom end rotating assembly balanced so the revs can really he raised a bit to extract more power. What rpms do you think these cams will start showing there strengths. And what max rpms do you think I can do. The head has new supertec springs and titanium retainers. And from reading on this form I went with a tomie oil pump and larger oil pan with 1.1m block restrictor, next I installed a head oil drain on the back of the head. I'm asking cause I've never done a build like this and after reading on this form the only option that would have been better than a tomie oil pump is a dry sump setup. Which I might do in my next rb26 build when the time comes.

Edited May 28, 2014 by MJTru

[XRATED]

Ha ha ha... with a turbo the size of Bolivia... 10.5mm (or whatever they are) 272's are going to be too small, but better than stock.

there is no way you will get the best out of that turbo with stock cams as opposed to anything with more lift and or duration....

[MJTru]

Wow. Figure you would have more detail than that. And whats the ha ha for. Lol. 272 are to small.???? I can agree which may be the lift which I think is not stock but very close to it. The turbo is big, but not as big as you make it seem. The car is only for drag racing. Also I do know a bit of things to go fast, but I have always lived my life with an open mind to new ideas when it comes to this sport. No one can know it all and tried it all. XRATED you sound like most of the guys over here. Lol. Short answer and it dont help to much. Never the less I'm appreciative. That turbo is a gts72 and looks big cause there is no valve over on cylinder head as yet. Im planing on taking it off and replacing it later, but as for now it will have to work. Bolivia kml.

As for the head you just cant stick any cam with max lift if you dont know how much your valve springs can allow for. Then your seat pressure and so forth. I come here on this site because I know guys that have tried different combination and have been successful as well as blow a few motors up. All im doing is learning

Edited May 28, 2014 by MJTru

[XRATED]

It's all good James... I probably sound like most of the guys over there because I used to live and race there (Miami/Ft Lauderdale etc)... With the big open highways, a fantastic drag strip 11hr up I95 and events like standing mile that are run frequently, loosing a few hundred rpm in boost threshold or a hand full of hp under 4000rpm isn't as big of a deal as compared to tight twisting drivers roads in Aus.

Your large frame single is quite large in comparison to twin low mounts like N1 or -5 garrets that most of us run, so take advantage of all that potential air flow and run the biggest cams you will feel comforatble with.... afterall it's drag racing I would class 272's as a mid to low range cam for a 26 depending on the lift.

At the end of the day, I'd run what you have..... get it to the track and have some fun. I would highly recomend and suggest aftermarket valve springs and retainers that will work with the HKS cams, it's cheap insurance especially with the rpm range you'll need to be looking at for racing with that turbo.

... just watch your gearbox at that power level, if it's still stock then use a reasonably soft clutch. 3rd gear will thankyou for it.

Cheers

Justin

[XRATED]

oh and most of my post's are short because I'm usually posting from work (when I'm supposet to be working :-))

[SiR_RB]

I made 410kw on e85 stock rb26 cams

[MJTru]

Well I was trying to have you be a little bit more detailed. I ran stock and n1 twin turbo set up and I just ran out of air for drag racing. I have a nice r33 that I drive around on the streets. And later on ill be building the motor. That car set up is a GTX3582R with a 6boost twin scroll manifold T3. Tail twin 38 gates.

Its very responsive and still hits harder than the twins to me. Just a small bit of lag in comparison to twins, nothing a drop in gear cant take care of. Only down side I see. Is its a tight fit. A/C still intact and all.

As for the cams ill mesure it today and let everyone know the right lift mate.

I mean its for drag racing but I still would want some help with the setup. From what your saying under lets say 5000 rpms its lazy. Im good with that. I tend to dont care and leave the line hard, as for gear box there like 600 USD over here dilivered. I can damage a hole bunch of them. But if the motor keeps messing my gear box up I will definitely upgrade it. I text from work as well.

I've been on this site for quite some time now, and I cant remember speaking to you before XRATED. Not that its a bad thing. I grown to know the people that know whats going on. Not by no means saying you dont mate.

What rpms do most drag gtrs run.? Next do you know how some gtr's seem to do a rwd burn out. Is it a torque split controller? ??

Thanks mate.

Edited May 28, 2014 by MJTru