we got three of the these exhausts today and already installed one (the other two go on customers' cars tomorrow morning). anyway, the install went well though the instructions need revisions (i will pass them onto the manufacturer on monday). just make sure the car is cool when you do the install because you have to snake your hands around the catalytic converter. also, you will need two internal torx sockets (e10 & e12) which i imagine most people don't have. you can use a 12 point 8mm (or 5/16") wrench in place of the e10 (i have a craftsman ratcheting 8mm wrench that works great for this application). other tools required are a t25 torx wrench, flat blade screwdriver, 12mm wrench/socket & wd-40.
things to watch for:
1. the instructions are missing step "6" which probably tells you to remove the engine cover so you can access the bolts on the cat. conv. heat shield.
2. after you remove the three bolts holding the cat. heat shield you will need to pull up on the left end to release a clip (though there is no need to remove the shield, just move it for access).
3. the factory gasket is reused but can be damaged easily so be careful when removing/installing it.
4. the two rubber hangers that hold the supports on the muffler are very difficult to remove from the factory muffler. first remove the two bolts holding the muffler to the cat.. next, use plenty of wd-40 on the rubber supports and remove the left side first. then spray the right side rubber with wd-40 and pull the muffler off.
5. when you are finished installing the muffler, use a good degreaser (i use brake cleaner) to clean the outside of the muffler. if you leave greasy fingerprints on the muffler, they will "burn" into the surface once you heat up the muffler.
i would recommend running the muffler for about 15 minutes (just idling) and then shut it off and let it cool for another 15 minutes. this helps to "burn in" the muffler packing for better life. an interesting note is that this is a motorcycle-style muffler that uses a fiberglass type packing (you will notice the smell after you first run the engine) - most automotive mufflers use mechanical baffling. i'm not sure what the life expentantcy is on the packing in this application but you will probably notice that the muffler will get louder over time. at some point you may need to have the muffler "repacked."
as to performance, i drove it around some this evening and though it is very subjective, i would say the smart feels peppier, especially in the 2k-4k range that is important for normal around town driving. the sound is a little louder but does not seem to produce much "droning" that can happen with some exhausts (just ask a corvette guy about aftermarket mufflers). overall, i feel it was a good investment based on the retail price of $349.
regards,
ken zeller