I have a jdm t3/t4 .57 trim turbo with a 20mm port on the exhaust housing for the wastegate. I have a 38mm dual port wastegate with a 6# spring. If I run my 6- stage boost controller, how much boost can I run before the 20mm hole becomes too restrictive and causes boost creep. I don't really want to port the housing if I don't have to beacuse I don't want to weaken the housing, but I can weld a pipe to the the header. This is on a hayabusa so room is limited and I'll only need 18-20 psi out of it.

 

the more boost you run, the less exhaust gas goes through the wastegate.

 

thanks, I was thinking bass ackwards.