So I just went to go get tuned. I have a 2007 sti. My mods are 38mm ewg, TBE, GMBS and fuel pump. It was a road tune. When we got on it in fourth we would get boost cut at about 5000 rpms. The duty cycle would just drop to 0. I checked all the connections and I didn't see anything wrong. My tuner thinks its that I have to strong of a spring in the waste gate but its only 1bar. I need help guys cus I really don't think the problem is that I need a .5bar spring. Thanks for your advice.

 

Maybe he mistakenly tuned your Cobalt?

 

What is your target boost? Were you hitting that target at all before the wgdc hits 0?

 

Did I rub off on you?

 

It's my car guys. It hit 22 psi and then cut. Target boost was 19

 

Probably fuel cut

 

I doubt it cus my check engine light came on and it read something about the duty cycles.

 

lol.


Well whenever I hit fuel cut, it was when I overboosted around 3 psi over target boost and I would get a Wastegate CEL, I agree with it being fuel cut man.

 

Fuel cut on a stock 07 ROM is set at 33.55psi absolute, so just under 19psi of boost. Your tuner needs to increase this value if he hasnt already.

I dont think you need a softer spring. Ive never heard of anyone boost creeping on a properly setup EWG, especially by 7psi over spring pressure. Hell I get creep on my 15psi actuator but only by a couple psi at 6K+. And this is on an internal gate too. My guess is that you either have a vacuum line hooked up wrong between the BCS, wastegate, and turbo, or there is a mechanical problem with the wastegate that is preventing it from opening fully.

 

OK well what would you guys do in this case cus it could be vaccum lines, a mechanical problem, or the tuning. Should I take it to a shop.