On the flip side, I have a stock intake and custom catback using a Borla muffler, and it also sounds great, though nowhere in the rev range is it subtle or quiet. It burbles at idle and goes from there to haywire as the revs go up.I swear all I did was gut precat and install custom intake, and it sounds like it's got active exhaust.
30% throttle, silent as church.
Any deeper, I get this growl all the way to 5000rpm, when the sound is overwhelmed by the engine's rasp.
I believe I have the best sounding exhaust of all the spyders I have encountered, both in person and on this site.
They clean up your emissions when your engine starts up and the main cat isn't warmed up. Once the main cat is up to optimal operating temp they aren't needed. When removed, if you need to pass emissions you just need to make sure your engine is up to temp. Check the tread rpaltman posted for more info on what can happen if you don't decide to remove.Don't understand the term "precats"????
Dual TMs will make it sound like an Austin Healy 3000 and/or Aston Martin DB5. Noticeable during acceleration, but quiet a cursing speed. That is the only thing I have done to improve the sound. Very throaty! And I still have the pre-cats installed.