Ever since I got the car I get a very loud whistle when I boost. It's only seems to be at full boost (10-12 PSI) I'm not sure if it just the turbo or a boost leak or something else completely. I seem to hold PSI fine so it doesn't seem like a boost leak but shoot me some ideas on what it could be.

 

your turbo is going out

 

Do you have a boost gauge?

..which tune does 10-12psi?

 

Yes, Speed Tuning USA, why?

 

I'm assuming he's asking because most tunes will run between 15-18, not sure why speed tuning is so low.

 

A lot of people recommended them. It was $199 compared to other companies which run $400+. Same HP and torque gains just less boost.

 

Doesn't work like that. Two good quality stage 1 tunes for a k03, one running 18psi and one running 12psi the 18psi will win. I'm wondering if you have a vacuum leak or similar somewhere. I can't imagine a tune only going from the stock 7psi to 12psi

 

I contacted multiple companies and the HP and torque gains were almost exact. So I don't know what to tell you.

 

I know, that's why I'm saying you might have a vacuum leak. It could also be your turbo is getting bad and it isn't building full boost (16psi+)

 

Possibly, I believe I do. How do you recommend doing a boost leak test? I've only done them with pressurizing the system but my friends air compressor is broken right now so that won't work, in my opinion that is the best way to do them.

Or maybe the turbo is bad and if that's the case well oh well 12 PSI works.