Quick question of what's the best size test pipe for me.

I'm running stock headers and exhaust. I plan on keeping it like that for a while. Should I get the 63mm or 70mm test pipe? I'm assuming one bigger than the size of my stock exhaust would hurt performance or does it not matter?

Thanks!

 

You should get a 60 mm, instead of the 63 or 70. I believe Invidia might be the only source for a 60 mm, unless you find one on ebay.

 

60, or 63 is fine. Some only make 63s.

 

As stated 60mm Invidia for stock exhaust setup. A tune along with the testpipe is highly recommended.