Hey, just thought I'd post this review of the catback I stuck on my car last week since not too many people have heard of it.
The thing looks just like an N-1 from behind the car, sounds pretty much just like it as well. The pipe is 80mm (3in) with a 115mm tip (ala N-1). The 2 things I like about it over the N-1 (which I had on my S13) are that it's a 2 part exhaust, so shipping is a bit cheeper (N-1 is so long they charge extra for it) and the GP dosnt' have a resonator. The lack of a resonator obviously helps exhaust flow a small amount, but it also leaves the exhaust with a nice deep tone at idle that was lacking on the other exhaust's I've had. But the thing never gets too loud or obnoxious (nothing at all like a Fireball exhaust).
Ground clerance is the same as the N-1 (which is to say poor) but I havn't scraped it yet even through I just droped my car 1.5in lastnight.
If you interested in it, ken at
http://www.enjukuracing.com has them for sale for $399 (and that's the biggest reason I bought this over the N-1).
later,
Paul