ArcticSIlver

Does anybody know the specs on neo valve springs? I can't find them anywhere.

No ideas? Haven't herd much of rbs and valve problems? Is this a freak accident no one cares to speak on? Still keeping me up at night....

Ill run aftermarket valve springs if I need to, I was just planning to slap all my goodies on the new motor and get a tune and drive it. It had only 10 events on a legit rebuilt. Maybe 500 miles on it. It was on 17psi boost and at the moment I had been on limiter for 3 seconds maybe? However this is a drift car and I have been giving it bloody hell ever since it's been running and tuned.

Link g4+, I really need to get to the bottom of this cause, it's driving me nuts.

Really no one has a clue? This is keeping me up at night.

Was at the track a couple days ago when my motor made horrible noises at rev limiter. Pulled the motor out and took the head off to inspect. One exhaust valve broke entirely and bent all the rest in the same cylinder (#1) for obvious reasons. I am very unsure what happened, I suspect valve float? Rev limiter is set to 7800. 10 events on a fresh rebuild, standard engine besides arp head studs, arp rod bolts, ACL race bearings, and cometic head gasket. It was running fantastic and rock solid all year. The valve spring, keeper, and retainer were all in perfect shape. I find it curious though that the valve stem was not bent, almost like it did not contact the piston at the time of breaking. Timing was dead on, and car was dyno tuned by a very good tuner at 412hp. Any ideas? would like to prevent this on the new motor.

I will post up the dyno sheet tonight. Last night i realized i did not put the compressor o ring on. were doing a boost leak test today and if its leaking real bad ill fix that and throw it back on the dyno to see if it fixes the issue. Boost curve curvs up from about 3k to 4k then at 4k it holds 14psi flat untill about 6k then dips a couple psi to redline. He even threw in extra injector duty cycle and closed the wastegate a bit where it starts to dip to see if it would help but nope. Boost is controlled via mac 3 port solenoid and link g4+. Fuel is 92 octane. Have not measured compression ratio but Its probably a smidgen higher than factory, stock headgasket thickness was used on the head that has been resurfaced 4-5 times and the block resurfaced once. FMIC is a good sized ebay item. I really hope its just a massive boost leak that does not show itself untill 15 psi, i had high hopes for holset, but i may end up having to go with a legit turbo, which sucks because i just paid 450$ to have a custom down pipe made.

HY35 RB25 NEO not making power? So I rebuilt a stock rb25 neo with cometic mls head gasket, arp hardware, freddy intake mani, top mount turbo mani, HY35 turbo, walboro pump, 550cc injectors, tial 38mm W/G, running Link G4+. Got tuned today by a very good and reputable tuner, goal hp was 400whp and only made 280whp? The motor runs flawlessly, but boost was solid from just after 4k to about 6.5k and boost would fall off. He said the turbo is reaching it maximum volumetric efficiency as the AR is to small (.65) or the turbo is damaged. Now from all the research ive done I thought the HY35 was capable of 450ish hp on rb25s? Am I mistaking? Does anyone have any dyno sheets running the same turbo? Thanks - Josh