Dan 'turbo turtle' recently did a significant overhaul to my car. 2002 wrx exhaust intake big TMIC cobb stage 2 93oct Anyway I ran the car for 2 years and it ran solid 16psi at full throttle. After the many many leaks were fixed by Dan the car came back with this boost ocsillation problem. Dan tested and found that there are no leaks and I'm stuck at this point. Boost bounces at all throttle positions, but other than that the car runs great. LOOKING FOR SUGGESTIONS...LET THEM FLY. Thanks.
Mechanically, I would check the wastegate. Do you have a roflbov as well? Tune-wise, it might be hitting boost cut. Not sure what the parameters look like on your Cobb map. Can you post some logs (APV2 should allow you to log with your cable)? WOT on flat ground from 2500rpm in 3rd gear maybe?
From what I've read on nasioc ^^^ you might be on to something with boost limitation. I keep wondering how I was OK with leaks and NOT OK without leaks. But as you might expect I would be AND AM boosting quite a bit more now that the engine is tight and together. And quite possibly I'm overboosting the perameters of where the ECU wants to be. I have hit 25psi max and easy will go over 20psi regularily when I floor the throttle. We checked the bcs and that is fine. (I have a knockoff hks bov to answer your question). Is there a way to turn boost down?
25 PSI is a major problem (heck, even 20 without the proper tune to handle it). If everything checks out mechanically, I'd strongly recommend a custom tune. Sheen's right, logs will tell the story.
For the record, I had nothing to do with any of those mods listed. The car came to me with some leaks in the boost/vacuum lines. I fixed those leaks and now the car has this oscillating boost problem. I suspect that the car was tuned while it had the leaks. Since then I have suggested a couple things. Get a proper tune, check BCS, change the restrictor pill. The BSC checked out okay after some cleaning. The restrictor pill is aftermarket and super tiny. I have a stock restrictor pill for him to try. The car has another problem, when it rains, it stumbles and nearly stalls out. I have not had time to properly diagnose both these problems, although I have asked for him to come back to me. ~Dan
Hey Dan! Didn't mean to infer that the mods were your doing. I just threw this thread out there in the hopes that someone else has seen this. I'll try to schedule something with you but I just want to be as informed as possible before digging around the engine. It sounds like a tuning issue the more I research it. I should run a log. Pull the tune back to stock replace the pill and retune and see how that goes...
Sounds like you've found the problem. An incorrect pill size with the mods mentioned would cause boost issues.
