[Jon_UT]

Right now I'm running a flowmaster y-pipe into a 3" in/out borla xr1 muffler. I'm going to purchase a borla proxs muffler which comes in a si/do but the in/out is 2.5".

So should I buy a new y-pipe collector to fit exactly or would going from my 3" y-pipe to the 2.5" inlets make any difference?

 

[StormTroopin]

Why don't you just buy a 3" si/so?

 

[ostaF]

The si/so proxs mufflers are 14" bodies.

There's a 19" body 3" SI/Dual 2.5" outlet here: Borla 40349 - Borla ProXS Mufflers - Overview - SummitRacing.com

 

[Jon_UT]

oh lol I must of over looked the 3" in / 2.5" out. Perfect, that solves everything.