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hi every body just need some advice from people that know. iam running gt3040 powered rebuilt rb25 with gtr rods , wiseco forged pistons , tomei step 1 poncams and ported head. im running stock hydraulic lifters and valve springs. im wanting to rev the motor past 7000rpm to take advantage of the extra top end this gt3040 turbo gives me. whats a safe red line to have? thanks carl.

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Mine was set to 8000rpm.

That was knowing full well it woould see the drag strip, and it did a few times :)

Stock head aswell, not even cam'd

So i cant see why you cant do the same if its still making power.

You have the rods & better bolts, so DO IT

Does anyone know for sure or has had experience when valve float has started to occur in the 25's with whatever modifications they have had done?

Im curious to know if it happens often or not at all, i have yet to see anyone complain about 25det and valve float. Ive heard its a problem in neo25's cause their springs are weaker then the previous models, is that true as well if anyone knows?

Well thats good to hear. Just that were upgrading the springs to some stronger Isky ones for the 25/30 just to make sure..we will be running around 22-25psi outta the 3540. Just wanted to check incase anyone had run into such problems before.

Ok so someone has run into problems...well our redline on the 25/30 will be 7k due to standard harmonic dampner, so with the stronger springs we should be good.

What turbo may i ask were you two running R31Nismoid/turbo87?

Edited by r33_racer

I also ran into valve float at about 21psi. It started around 4k according to my tuner.

That was on an HKS t300s turboed stock cam'ed s1 rb25 making about 240rwkw up top. I've got my rev limit pegged at 7300 more due to worries about the stock rods than the valve train.

im running tomei poncams step 1 252 degrees duration at stock 8.5mm lift. now wouldnt running these cams with stock lift enable me to run similar rev limit to if i had the stock cams still installed??? if im going to run 22psi on hi boost do i need to restrict revs to 7000rpm or can i go to 7300rpm ? without valve float any ideas people???

If installing pon cams I'd recommend upgrading the valve springs to gtr items. With stock lift I'd say you should be able to hit 7500 but you'l certainly find out. Didn't you have a gt 30 with nissan exhaust housing before or am I getting mixed up?

Cheers

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