IHATESUPRAS

I drive a 99 SS with an M6. I will soon be swapping my Macs w/o cats and Flowmaster for TTS w/o cats and Corsa exhaust. I ran 13.0 at 109.7 with my current setup. Will I notice anything?

LEO

iTrader: (3)

I think there will be a minimal change if any. Don't expect too much - maybe a tenth and 1 mph.

Colonel

I agree. Not much. Look for power elsewhere unless you really just want the nicer headers and different exhaust note.

WeatherGuy

For the money you are looking to spend here, I would definitely consider a cam instead, or possibly a cam with some head work. That will make a much bigger difference, and could get you at least a half second if not more.

FWIW, everyone disses the MACs, but you can do a lot with them if you are willing to port/fix a few of their problem areas. On the other hand, I would probably nuke the Flowmaster muffler for something else.