Originally Posted by 1fastdoc
I've searched these forums and others and I've had a hard time finding a definitive answer. I came to the M3 from mustangs, which I've owned and driven for 20 years. I love the sound of an American V8 and want something like that from the M3.
I definitely don't like the raspy sound that I hear on Italian cars and it seems that a lot of the aftermarket systems mimic that.
Emissions testing here is done annually so it looks like I'm limited to a slip on system. As far as going for a throaty, non-raspy sound I've watched a lot of videos but obviously it's difficult to appreciate what they sound like on my laptop. Gintani seems to be the closest.
So am I really limited to a Gintani slip on or cat-back system? Are there full exhausts that are emissions legal? This car is a DD/garage queen but will see track time occasionally (maybe 1-2x per year).
There are no full systems that are emissions legal. Even if it an OBD based test, you will fail the cat-readiness portion of the test. You can, however, change out the mid-pipe to one that removes the secondary cats. This is not bolt-on, however. You will have to cut the exhaust just past the stock primary cats, then weld the aftermarket midpipe in. You can then add the cat-back of your choice. This will give more hp than just a catback alone (which really only changes the sound), and you can pick products to custom tailor the sound.