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Won’t be able to adjust rev limit and honestly I never get near it due to my fear of losing the oil pump. At 5k rpm boost builds with no issue no hiccups just the fact that it is a thousand rpms slower than where it should be. It’s a .82 ar so really nothing crazy. I’m going to unplug wastegate signal and go for a drive keeping an eye on boost and how fast it builds. If it behaves the same then my guesses would be cam timing is off or engine is tired/ low compression. It gave me no issues on stock turbo and manifold on 12psi. 

  • 4 weeks later...

Something so stupid that I hadn't considered until I found someone with the same problem. f**kin gear ratios. how bad would they effect spool up? With a final drive of 3.9 and thick tires in the back making my effective around 3.8 that would definitely cost me 500rpms in spool right? Found someone with the same setup same power but .63 hotside spooling up at 6k. Difference between me and him is 3.5 final drive and 295 tires making his effective ratio 3.3. Could this be the answer or should I keep looking into it?

Higher numeric final drive (shorter gears) would affect the RPM you spool by because the engine will reach higher RPMs sooner. But if you were to do a time to torque/boost measurement you would find it to be faster because the engine is getting up to an RPM where it can spool the turbo sooner. You can play games with dyno load to do this, it's effectively brake boosting. 

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