Inliners International Forums General Discussion Engines Looking for exhaust recommendation for dual to single

XXL
Use what the collector size is It will keep things simple and much easier to deal with. 2 1/4 collectors If your making your own Y pipe you can size it to 2 1/2 Or even a 3inch. You can then down size it to 2 after the muffler.This will help keep some of sound down Out the tail end.
A added Plus in keeping the pipe size down Is it will maybe?? cost a little less money.Along with the noise.
Hope this helps.