ok... for teh first time, I experienced boost creep today. I have had the exhaust system on for about 8 months now, and even in the mountain and autocross, its never happened. Its a custom 3" exhaust with a bellmouth DP (no cat), 3" catted (turbo XS cat) mid pipe, and 3" axle back. I do not have EM yet, but even though, its never happened until now. I went to the mountains last weekend and drove it hard and nothing happened, but today I was passing a car in the top of 4th and it just fell on its face, and the cruise light started blinking and the check engine like came on... Why hasn't it occured before now? I mean in 8 months of driving, it should have at least done it once. Instead, it happened twice in one day. :eek3:
hmm...my boost creep happens top of 5th but no flashing codes or cruise light blinking. it just falls on its face kinda like what you experience. i have a turbo back exhaust catless like you, but i have EM. port the wastegate, or get a bigger turbo and it'll be fixed.
Your wastegate is too small. You need to port it. I bet it was really cold out when this happened and you were in a high load state in either 5th or 6th gear...
Yep, I was always under the impression that with the single cat, it would create enough back pressure to prevent this. Why hasn't it happened before now?
I do plan on doing the EM in the near future, so would it be worth it to port the wastegate now? If so, do you all do it at SOG or does it need to be sent out? i.e. Deadbolt
you could do it now, or after EM. i still get boost creep w/ EM. SoG does do it...i think its like 100 bucks if you pull the turbo off. 400 if they do all the labor and porting. i need to port my wastegate, but just been lazy to pull the turbo off.
It could be that your cat has burned up just enough to not have enough back pressure after 8 months of use that could be why it is happening just now. Also correct me if im wrong, but a quick fix would be a mbc.
mbc? I have another universal cat that is brand new, but wouldn't the other one have started rattling?
Now that i think about it you are right about the increase in backpressure of the cat over time. But exhaust systems decrease in back pressure over time which might be your problem. Just to be sure your car would build boost untill it hits around full and then drops down to like no psi before jumping back up again and then falling again, if so I used to get it in my 02 with a catless tbe. The guys at clubwrx told me to get a mbc and it fixed my problem. Still got a little boost creep in the higher gears without the fall off that the stock boost solenoid causes.
Installed a vf34 and supporting mods, and i also see boost creep. Had to take the turbo off again, and port the wastegate hole. Now, boost id solid 18psi.
this is not an argument of any sort just personally i think boost creep can be solved by tuning some maybe better control of wastegate. Porting the turbo - unless you open up the hole significantly i dont see how much it will help. If its too large then you need a new cover/gate. I think if you have turned the WG arm too much then even when its fully open its not enough. I think opening the WG larger will total the same amount if not more than porting the exit. and I think the air turbulence in that chamber contributes to the air flow through the WG. so maybe DWG or a divider plate in that area to streamline the flow better just my opinion noob dont know too much