Alright, at the track this past weekend there was a guy there promoting his own exhaust system called "Thunder Alley" He came by to every truck with a YZ/WR 400/426 and offered to unbolt what ever exhaust system you had and install his then let you spin some laps on it. He'd then either leave it on if you wanted it or put yours back on. This exhaust was a mega phone style open end system. He said he had a spark arrestor which made it a little quiter with no noticable lose of power. I tried it out and the 1st thing I noticed was it was louder then my stock YZ system but much quiter then my friends Pro Circuit system. It had a noticable improvement through out the power band and I found myself pulling wheelies everywhere and overclearing jumps on my first lap. I was very impressed. My friend with a '98YZ400 said he thought it was better then his Pro Circuit setup. It was a high header/muffler combo. Very profeeeional/clean installation. I talked to a couple other guys that tried it as mine was being installed and they also were very impressed. The cost was $350 for the setup or $375 with a spark arrestor. The guy is at Lake Elsinore about once a month if you want to get in contact with him I'm sure he'd let you know when he'll be there for you to try it out. Let me know if you have any questions. No, I'm not affiliated with this guy or company at all I just wanted to let you know of another exhaust option which I tried on my bike 1st hand and was pretty impressed with. Here's the contact info: Thunder Alley Bob Murray 559-584-8109 ------------------ Khris "What's that?" "It's a Yellow 99' YZ400!!"