I have a universal apexi n1 na muffler welded to what looks to be 2 inch pipe from cat back from like minakee. Now the piping is crush bent with no resonator and is more crushed in some spots from like rocks and crap, i have 2 major bends. This is creating turbulance going from small to big and crap so i need to redue this system. I wanted to know would i see a better performance increase with a resonated test pipe, 2.5 inch madrel piping with resonator, and a n1 TYPE muffler off ebay, im a little tight on money, compare this to what i have now.

 

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I would check out some classifieds in here and on other boards. I bet you could find a good, used full catback system from a reputable company. It's gonna cost you a lot of money to get a muffler shop to mandrel bend an exhaust unless you have a turbo car which it'll be worth it.