[Empire087]

So, ive always been a big fan of less restrictive exhaust, but im trying to figure out if its worth it. ive got a 3.5" midpipe i made, to the factory msport muffler. I love its sounds, and how quiet it is off throttle and crusing(stealthy when needed). However ive been debating building a new axle back setup to help relieve any back pressure woes it may have. Also trying to do this before i have it tuned, to eek out any more performance i can. Any thoughts?

[Skyhigh]

Every muffler introduces back-pressure / resistance. This said, very often it is insignificant to cause performance degradation. This said again, there is a reason why valved exhaust shortcut the mufflers at high RPMs
There is no black or white, but the less restrictive your exhaust is, the better. The real bottleneck will always be the downpipe however. Start there.