So the title says I cant stop my over boost. I have a rapid cooler kit, 4inch dump cat back and just installed a modded housing and 12lb actuator. but still just over boosts. so a few details. I noticed on the 12lb actuator it has 10mm less travel than the stock one. has anyone else still had overboost even with a modded housing? I have the standard bov hooked up without the vac line connected and it opens at about 8psi and vents enough air to hold 11psi but without that set up it just overboost crazy mad.

So the title says I cant stop my over boost. I have a rapid cooler kit, 4inch dump cat back and just installed a modded housing and 12lb actuator. but still just over boosts. so a few details. I noticed on the 12lb actuator it has 10mm less travel than the stock one. has anyone else still had overboost even with a modded housing? I have the standard bov hooked up without the vac line connected and it opens at about 8psi and vents enough air to hold 11psi but without that set up it just overboost crazy mad.

Have you had the car tuned since you fitted the actuator and modified exhaust housing??

It hasn't been tuned yet but it still shouldnt run more than 12psi. I have the turbo boost straight into the actuator so no computer controlling boost. Before I changed the housing and the actuator I had the standard actuator hooked into boost and it would run 5psi up untill 3500rpm then start to overboost. now with the 12psi it spikes past 15 without even trying. it just seems like its still not passing enough gas through the wastegate hole. with the bov venting some of the boost it holds 12psi fine.

I dont think that's its not venting enough gases I think your actuator is staying closed too long.

How tight did you string the actuator up? Ive had 2 customers come to me with the same issue and when I pulled the turbo off to see how hard the actuator was adjusted they had almost taken up all the travel of the actuator. I have 14 cars running around with the same modification on the turbo as yours and not 1 has ever boost spiked. Call me in the morning so we can talk about it.

ive got the same problem with my car. ive got the rapid kit and it overboosts on a cold night because I havent got my wastegate done yet its just too small to pass through all the gasses so in turn the gas that cant escape circulates in the turbo and causes it to spool faster making more boost. Porting the wastegate or getting a bigger one should fix the problem....anyone correct me if im wrong.

You are correct. It can be dangerous (for the engine) on a cold high going hard.

Edited April 30, 200818 yr by veczar