I got the new to me 03 RX 1 Mountain sleds out yesterday. I installed a used white knuckle exhaust on one machine, primarily for the weight savings. The info said 2 db louder. First off, no gripe to the fella I got it from. Greg gave me a fair price and we had a excellent transaction. It seems this system has an awful resonance at about 7500. The actual loudness is not bad. I am thinking to wrap the exterior, or something. Any suggestions? Otherwise I am going back to stock. The other sled I bought has a homemade under tunnel exhaust, 2 glass packs with WR 250 baffles. It sounds great.