Originally Posted by RaceGass

The 2 bros M7 is one loud sum beotch w/o the P3 insert. At idle its obnoxious, when taking off its embarrassing being soo freekin loud and going no where until you get into third gear.

With the P3 its got abit more backpressure so it feels like it has more umpfff off the line.
All around its way better w/ the insert.

The length of the canister of the FMF is 1.5 times the length of a 2 bros. If I were going to buy again I'd go w/ the FMF Q4 & powerbomb header.

Originally Posted by DJFields

IF you want quiet, stay with the stock system. If you want performance any of the available sytems are very good. Just remember you can't have both. I have had the HMF since summer 2006 and recently added the FMF PB/SS Head Pipe and love it.

Originally Posted by glava2876

I have two 2007 KLX 250s and purchased an HMF slip-on and QC insert for one of them.
I'm in the noise contriol business and within the week I plan on taking my sound level/ frequency meter home to get the sound level of the stock pipe Vs the HMF with and without the QC insert -I was actually able to get a copy of the test standards to get the distance etc. I'll post the results.
Glen