How To Make A Rb25 Rev Alittle Higher

[13thracer]

im about to start sourcing parts to begin my build on my old 25 sitting under the house and would like to know from people who have done it, how they get there 25 to rev higher i would like to take it out to about 8500RPM if possible. motor will be forged bottom end all balanced obviuosly was thinking lightened flywheel and harmonic blancer, port and polish head, set of valve springs and i have a set of hks 264 with 8.5mm lift intake and exhaust cams that will go in as well. any other suggestions to get it to rev happily and safely.

thanks

[SLY33]

why?

[gun32gtr]

is there a gain to be had???

[paulr33]

as the others have said - why?

revving higher doesnt just give you more magical power

average power makes a car fast, focus on that

[Devils_Advocate21]

As the others have said, the advantages of power are had earlier along, not right at the end, if you want power increase the turbo put NOS in, 8500rpm aint going to gain you much if any at that high, and all it is going to do is wear things alot much alot quicker than normal operating levels, No gain in it, pointless thread.

On another note, why dont you check out the FI dyno results, and you may just see were the power is to be had with the extensive modifications list to go with it.

Cheers A

[markimak]

throw a PFC on ur stocker and run it to 10,000rpm and max ur tacho out..

but in all seriousness. u make peak power more so in the medium.. its not like a vtec engine..

[R31Nismoid]

I only needed 8000rpm with my GT30 setup.

Was making power there, but much over that there was no point.

All depends on the setup as to wether or not you'll need 8500rpm...

So throw some more specs out to us, i would suspect you might not need that much.

[13thracer]

was aiming at 8500 so i have alttile lee way so limiter about 8000ish will be stock crank and rods preped accordingly with forgies bottom end all balanced lightened flywheel and harmonic blancer, port and polish head, set of valve springs, set of hks 264 with 8.5mm lift intake and exhaust cams that will go in as well, add in microtech to control it all turbo i am still undecided on it will be street driven looking for 250rwkw want power and boost to come on hard and early and hold as best as possible right through to redline (where ever it set to to?)

[R31Nismoid]

With 250rwkw, there is no way you'll need 8500rpm dude.

A GCG hi-flow or similar (that will make 250rwkw) just isnt going to make powee up there

Around 7000-7500 is where the fun is going to end for you so an 8000rpm limiter is going to be more than ample for your application.

[13thracer]

cool thanks nismoid i sort of figured that may be the case but for arguements sake lets say i was to throw on something in the gt35/40 range if i have a change of heart and go stupid would you say there would be an advantage in letting it spin to 8ish

[r33_racer]

why is everyone telling him its useless or 'why' he wants to do it rather then actually trying to help him achieve what he wants to achieve regardless if its practical or not?...if its possible then why not let him do it. Its his car, engine and money and ultimately hes responsible for it all.

Everyone says there is no need to rev a 30det past 7000-7500 we send ours to 8000 with possibility to 8500 cause it just keeps making power. Sometimes having a wider powerband helps.

[R31Nismoid]

But you keep making power, with this blokes aims, he wont be making power there.

Each setup to its own.

And IMO spend money where/when you need it, not just because you can

[BAMR33]

On a different note. Has anyone seen any more useable power by extending the rev limiter to say +-7100rpm on a stock internal rb25 with hi-flow turbo & supporting mods at the 18psi mark?

Edited February 5, 2007 by BAMR33

[r33_racer]

I thought he said he was still undecided on the turbo....with his mods or planned mods he should aim higher. 300rwkws min i think. No need for the engine rebuild otherwise.

[13thracer]

i think the 300 mark may be a little extreme for now any way, no reason i cant bolt on a bigger turbo down the track if i get bored and want more.

the engine is being built with more power in mind for later i think 250kw will scare me enough at the moment

[R31Nismoid]

If your gonna maybe go for more power maybe... Then i would make one change

Put a set of GTR rods in there. For $200 or whatever they go for, would make sense of RB25 rods for the price

[13thracer]

yeah i got five of those left i dont like talk about what happened to the other one and the crank

[Dale FZ1]

Put a set of GTR rods in there... would make sense of RB25 rods for the price

Are GTR rods the same length? ie. no probs with pushing the pistons higher/lower in their bores?

[DennisRB30]

average power makes a car fast, focus on that

True. That's why lifting the rev limiter is an enormous help to average power when you use a large turbo. Looks like this guy might want a GT35 and the extra revs will help a a lot with average power since there will be a lot of lag in the mid range. I'm sure with that turbo selection he wants more than 250rwkw at some time in the future.

[r3240sx]

Are GTR rods the same length? ie. no probs with pushing the pistons higher/lower in their bores?

Theres no point, but if you really want to rev that high the most popular setup is an r32 GTS-T conversion with forged internals and proper oiling mods. You could probably see 10,000 rpm safely..

Yes this setup is far superior to the rb25 in every way..

Also, this post is entirely inspired by sarcasm.