[QUOTE=Taylor123;10796207]
Quote:
Originally Posted by FoundNemo
The Mishimoto article showing no gains was done on a 460hp SS camaro, not the ZL1. You do not lose much power in the 2.1" exhaust range that far downstream on an NA motor, but for a 650hp ZL1 there is a little room for improvement. Power, throttle response and tone are both improved when you replace the pre-crink area back to the tips.
My shop cut at the pre-crimp area, welded on 3" pipes from the pre-crimp to the OEM tips with Magnaflow y-splitters and Maxflow 3" x 6" long x 5" body resonators on each side and I had them Cerakote'd black. People saying there is no difference are wrong. The internal inlet on the muffler is down to 2.1", measured with a caliper when we removed it. Already dyno'd before after and was worth about 11rwhp and 14wtq SAE (muffler delete and crimp delete both). Not bad for $600 including coating/fabbing/etc, looks badass. Can definitely feel a smoother acceleration too at WOT in the upper rpm band like its not as choked up. I'm sure modding the OEM cats to allow more flow (they are also choked up) would be helpful too. I've been considering buying a lightly used set and replacing all the choke points with 2.5" pipe or better and re-installing but not sure how much it would help with the cats in place still.
And for folks who want to flame, have fun, I dont care 
Where did you get the black spoiler? |
$250 remove/repaint/reinstall. Local shop with excellent work, repainted my OEM.