im doin a br3065 turbo and im doin custom ic piping. is a 2.5 inch pipe more than fine or should i do a 3 inch pipe set? ive been having piping blowin out of couplers so im gunna have the least amount possible.

 

go with the least diameter piping that you can to reduce the lag as much as possible. I typically go with piping the size of the turbo outlet. If the intercooler inlet is larger than the compressor outlet, I split the difference, or run with piping the size of the intercooler inlet.