jdmturbo1127

I have a Nissan 45V3 turbo that I want to use on my Y8. The exhaust flange has a 6 bolt pattern (pretty small), and after measuring it... it wont fit anything larger than a 2 inch pipe! So my question is, when fabricating up the down pipe, can I come off the flange at 2 inches then increase it to 2.5? Im only gonna boost 8-9 psi, so will that 2 inches hurt performance or anything? Any feedback would be helpful, thanks!