i have the borla side exhaust on my 98 cobra. from what i hear this is one of the few side pipe kits that don't hurt your hp. they don't help it, but they don't hurt much. they do look and sound great. the 180 bend is in the muffler. as far as other kits go i'm not sure. the only problem that i have is trying to put the car up on to a lift. the pipes and side skirts are in the way. other than that i love mine.