Make	Model	Exhaust brand	Insert	Decibel
Honda	CRF 250	Pro Circuit T-4	none	98.2
Suzuki	RMZ 450	Leo Vince	None	97.6
Suzuki	LTR450 atv	Yoshimura RS5	Factory insert	97

Notes:

*most 2009, 2010 Pro Circuit and Yoshimura newest pipes are passing

* all Leo Vince pipes we tested have passed

*most KX450F 2009 and 2010 do not pass with stock pipe

Dr- D pipes have been having a difficult time passing

Quads: best 2 pipes we have seen and heard good thing about are Leo Vince and Yosh RS5 with the quiet core insert

The Motokazie designed insert has been dropping about 3 dba off the exhaust. We only recommend this as a temporary fix. If your pipe is too loud (102-105) the insert will NOT be enough.

Quads: most 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.

Quads: HMF, Curtis Sparks, DASA 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.