so i just put a 3 inch full exhaust on my VR4, and im thinkin about getting a boost controller, but my question is, how much PSI will the stock turbos run reliably at? at that certain PSI, would i need to adjust the factory wastegate or BOV?

daniel

 

Ive heard 15\16 on stock fuel system. BOV may need to be upgraded not sure...up it see if there is a leak and go from there. if the PSI drops by redline your BOV cant hold it most likely.

 

It will need a new bov, the hahn stage two kit for the 420a comes with a vr4 bov and that this is useless past 12.