ok here's what i got: 02 wrx, stock turbo, ssac intercooler, perrin bpv, catless up-pipe, 3in bellmouth catless, spt cat-back, enginuity tune from tom (wall of tv's). here's the problem: i'm boosting normally in every gear except 4th and 5th. boost holds steady in 1-2-3 with little or no spiking. but when i boost in 4th/5th pressure will spike to 19ish and drop down to 15psi when it should be at 17.1. then if i continue at WOT boost will fluxuate like the computer is trying to correct a leak or a like it has a weak bpv spring. but if that were so i'd think that i would have the same problem in 3rd gear which is set for the same boost pressure. any ideas? similar problems? if you need more info let me know. i know it's hard to diagnose without a ride along. but that's basically what happens. i'm gonna try re-installing my stock bpv. thanks, matt
just a thought. were you tuned with your stock bpv? then installed your perrin? could try to tighten your spring or maybe you have to look at your wdc.... I had the same problem with my aps. I messed with the spring adjustment after the tune and I witnessed crazy fluctuations in 4th/5th. I adjusted it back and i held boost perfect just like it did when i got the tune
??. You mean in your tune? All stock ECU reflashes work within the bounds of the stock ECU... OP -- sounds like one of a couple things are going on: 1) Your tune is aggressive, and isn't pulling enough WGDC's for cold winter air. Thus, your car is overboosting, and the ECU is having trouble getting boost to sit right on target. I would consider this to be the most likely problem. 2) Somehow your BPV is leaking at high boost. This wouldn't necessarily explain your overboost, but it could explain the bouncing boost at WOT.
The tune was done like 1.5 years ago with a different exhaust and tmic. Either a retune would fix it or loosening the wg arm a 1/2 - 1 turn would probably work also. The new parts flow a bit better and probably need less WGDC which will cause the spiking.
mine did it the other day when it was super cold, i turned it off and turned it back on. it was gone, man was it pulling though.. ha
OK, problem, solved. Nate tuned my car today! What a difference, the car feels way more torque and way way smoother. No more bouncing boost.
As long as you keep the Ausie jokes to a minimum, I'm already chalk full of Russian humor (and driving). :biggrin::biggrin::biggrin::laugh::laugh:
Mine's overshooting a little too. Probably just need to increase the WGDC temperature compensation now that its frikin' cold out. Everybody's car should be making extra power now if your boost is staying the same as when it was hot out.
Yeah, I can tell you for a fact that mine makes around 30 wtq and 20 whp more then in the summer. Yay for cold air!
