I have one on my Z. It's not a bad slip on considering its only 215 and it's adjustable. I found that i got the most power out of it with all 12 discs in it. I didn't know which slip on to get, but there is a post on here with dyno readings with all kinds of different pipes. White brothers E-series with a head pipe came out on top if that tells you anything. thats my opinion.