zartroom

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?

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.

Long awaited update im sure!!!! f**kin sadly boost leak tested some more, ran it with the smoke machine, and checked torque on exhaust manifold to head, manifold to turbo, and intake manifold to head just to be an asshole and I can't seem to find the cause of the slow spool. Wastegate isn't leaking as far as I can tell. Every time I boost leak test it there is a hissing coming from the q45 tb. If I open the throttle the hissing goes away. Injector seals are fresh so not those either. Chairs are pretty nice thank you

Will update tomorrow. Just tested VCT, clutch in + in gear, solenoid clicks as it should. Also car drives normally out of boost. I almost miss the days when everything was stock

It for sure is absolutely terrible. the flex of 4100rpm full boost is solid my goal is by 4500rpm. As for the hot side I am running the thick cx racing manifold with a precision external wastegate 16psi spring. 3inch downpipe to a resonator and then the muffler. Wastegate is just a 5 inch pipe to atmo. Here's my new theory everybody else feel free to chime in. If my wastegate isn't bolted in as tight as it can be, therefore the fire ring isn't compressed flat on the flange... That could definitely cause some slow spooling issues no? Tomorrow im going to grind down a hex key just for it and crank em down see if anything changes. If this doesn't work then I really am lost.

Seen it as well, someone on that thread seems to be having/had the same issue. running moderate boost (17-21psi) and it only kicks on at 5.5k rpm. Boost leak tested it again as well as ran it with a smoke machine and still can't find anything.

Currently running a RS Enthalpy Z32 chipped ecu. Boost by gear or boost by tps would be awesome if I go aftermarket engine management. Car is loads of fun as it is... after e85 will be the point I'll have run out of things to do that don't involve engine overhaul

Gotcha. The more I look into it, it seems like my car is performing as it should. videos of others running a .82 ar on a 25 all seem to be hitting full boost around 5k. I guess I could've gone with a .63 and had full boost in 3.5k rpm but who wants a car that can only do 500hp? More boost and e85 is the way to go I guess. Thanks for the advice

Proven low reading dyno here in Tampa Fl, hence the discrepancy. If I could get the power to come on earlier that really would be my goal. E85 will get the extra punch out of it but I am looking for a wider power band. Boost leak tested, turbo bolts are snugged up, manifold to head bolts snugged up. That dyno day my injector seals blew out and we didn't notice theem, as well as running an electronic boost controller that caused some unpleasant wastegate fluttering. full boost hits at 5k-5.5k rpm all the way to redline. Since then I've swapped out the seals, and switched to a mbc and turbo does not feel as lazy, but power still comes on late in my opinion. Haven't seen many running this turbo as I would love to compare the differences.

Hello SAU, been a long time lurker and decided I will taint my record with a thread like this. Currently running a S2 RB25, Greddy IM, Precision 6062. Made 496whp at 20psi and I am wondering if pon cams would suit my setup. I am planning on going E85 soon and as I am doing my timing belt maintenance now, I thought what better time to go for cams than now? I wanted to gather some information from anyone else with a similar setup.