From what I have read online, CT is the best. However it is by a narrow margine. I just bought a Yoshi full system off ebay for $300. Wish I could jet it myself. I have to wait over a week to get it in and done. All it needs is a 145 jet but I wouldn't know how to do it. Any advise?

 

Dirt Wheels did a pipe shootout for the Z400 and CT Racing did come out on top. Yoshimura came in right afterand their was lioke 20 different pipes tested. Yoshi is a little cheaper but i don't know what comes with the kit. Just look up pipe shootout and you will find the dyno test results.

 

how many db is the hmf how many db will the silent insert reduce?

 

The HMF is 98db and the quiet core reduces it down to 91db..