Monday night I installed my Greddy Type S blow off valve. When I removed the old stuff I found that the vacuum line running to my BAC had a vey large crack in it. I replaced it and of course it made my car run and idle better, but now it's overboosting like crazy. I have my low boost set at 8.5 psi and it's overboosting above 12 psi. Could this be caused by the fixed vacuum leak? Or maybe I need to re-tune my profec b? Or could it be caused by how I have my blow off valve set? Any help would be greatly appreciated. Thanks.

 

try retuning it, if the bov vacuum line is bad it just dumps boost



mike

 

a vacuum leak with leak boost. it might be time to port the wastegate

 

I hope I don't need to port the wastegate. When the weather clears up I'm going to do a run with my boost controller off and see what it does. My theory is that if it overboosts past 10 psi with the controller off then the blow off valve is the problem. If it doesn't go above 10 psi then it's the controller. Until then I just need to take it really easy so that I don't go above 10 psi. This shouldn't be too hard.

 

how does the blowoff valve have anything do to with how much he is boosting, yes i know it could cause you to leak boost but not produce more psi???? Isn't he *overboosting* because even though he has a boost control it can only control how big the wastegate is. If the wastegate is tiny it doesn't matter how low you set your boost controller, cuz what matters it the wastegates size is will determine how well you can control the boost. =

 

well, if the bov is leaking air out boost is lower. if you fix the leak the boost will be higher



mike

 

Also with an aftermarket blow off valve you can adjust the spring tension that controls how much pressure it takes to open the valve. It's kind of like your wastegate spring. The softer the spring tension the easier it is to open and vise versa(sp). Hope that clears that up for you 1Revvin7. Thanks for the advice guys. BTW I fixed it earlier. I had to set it full soft to get things back to the way they were.