I have a comptech exhaust, and everyones been telling me that i spent to much money on it and they I could have had a custom made exhaust cat back and all. Anyway would it be a good idea to increase the piping diameter to 3 inch instead of the stock 2.5 - I think thats stop. I hope its not a stupid question , but tell me about my idea good or bad? Thanks :licka:

 

First of all the stock piping on the TL is not 2.5"...it's more like1.75" or 2" at most, I don't remember and second 3" piping is too big, you would lose all your backpressure and low end...if you're gonna upgrade to bigger piping don't go above 2.5"...and IMO, you did spend too much on an exhaust...I had a local performance exhaust shop make me a custom cat-back exhaust with 2.25" stainless steel piping and dual Magnaflow stainless steel, mirror finish mufflers for only $410 including installation...IMO it looks and sounds much better than any of the rear-section exhausts offered, plus with the cat-back there is a slight performance gain, unlike with the rear-section exhausts. Heres a pic:

 

Bigger pipes aren't always better because you want the exhaust system to be sized to cause the exhaust pulses to have good velocity. This scavenging effect creates a slight vacuum which in effect "pulls" the next pulse behind it. Then this gets more of the bad stuff out of the cylinder which means more good air fuel mixture can fill it. Pipes too small - the gases can't get out ; too big and then no scavenging help. Hope this helps.

 

my '65 road racing mustang sports around 980hp and is 4" piping - imagine the backpressure I lose from that!

AdamR

 

It looks dope! $410? Damn, you got h00ked up.