So as some of you know I have been pulling every last hair out trying to solve my overboost issue. I think I finally have a solution.....
So to get everyone up to speed, I am running open exhaust. I thought this was the cause of my overboost but it turns out it wasn't (though it definitely makes it worse). I got a hold of the stock/SCR midpipe for the car and put it on and I was still overboosting. Probably just a psi or 2 but enough to set the "Boost Sensor Range" code while running Jarek's stage 2 tune. Running the stock midpipe just like most of you are told me something else was wrong on the car. With Jarek's help as well as the help of a few of the members on the forum
I ruled everything out. Even replaced my boost sensor and wastegate solenoid (pressure converter), still no dice.
So I finally ended up opening up (porting) my wastegate in the car. Stock size is 7/16" and I've enlarged it to 9/16". I recommend using reamers in increments for ultimate control and even some "steering" of the hole. To go larger on the size you will need to get the flapper out of the way. To do this you will need to use a die grinder to remove some material behind the flapper so it can open up more and swing out of the way. Do NOT nick the flapper!
See before and after below. Had to remove the downpipe and engine mount again to do so but it appears to have come out ok (no holes
). After logging boost with no exhaust (downpipe only) I am right where I should be, so it made the difference I needed.
If you plan to run open exhaust you will probably need to do this to stay in the safe zone. Also, if you are running another tuner besides JR Auto's and you don't get codes with straight exhaust, your warning codes have probably been tuned out, you are still most likely overboosting, and probably slowly hurting your turbos.
It also sounds like another member will be presenting another solution (though a bit more involved) shortly
.