Random Exhaust Notes 2011:
*most 2009, 2010, 2011 aftermarket Pro Circuit T-4, FMF factory 4.1 or Q, Leo Vince and Yoshimura RS4 newest pipes are passing the 94dba test most of the time. Leo Vince Pipes have passed every time.
* Motokazie can offer you a 35% gift certificate for Leo Vince Exhausts, just email email@example.com .
*most KX450F 2009 and 2010 do not pass with stock pipe, 2011 KXF pipes are much better.
2007-2010 Dr- D pipes have been having a difficult time passing because of their large diameter outlet hole. In 2011 they offer a quiet pipe that has a smaller hole, you will need to call DR D and ask if they guarantee 94 dba
The Motokazie designed a simple insert has been dropping about 3 dba off the exhaust. We only recommend this as a temporary fix. If your pipe is too loud to start with the insert will NOT be enough.
Quads: All Stock pipes should pass the sound test.
Best 3 aftermarket pipes we have seen and heard good thing about are Leo Vince, Yosh RS5 with the quiet core insert and FMF factory 4.1. You must run the small diameter inserts that are given to you with the pipe.
Quads: Other aftermarket pipes that we are seeing at the track are NOT passing. If you have a large Diameter muffler like 2 hole, it is likely that it will NOT pass. You need inserts or quiet cores that reduce the hole to around 1.5 dia. Beside the hole dia. , the next most important is how long the muffler part is. You will need 14 to 16 in length to have a quiet pipe.
Quads: HMF, Curtis Sparks, DASA race pipes are not passing. You need to get the quiet inserts made be the manufacture or buy a quieter pipe. We have reviewed the manufactures websites and they do offer quiet tips, please buy them. These manufactures also offer 1 5/8 dia pipes and we highly recommend them. You will need to call the company and ask what they will guarantee for dba output.