CHM exhaust

[NetMXer]

If you live in CA CHM may not pass the sound requirements. Before I made a decision I called CHM and asked what sound level their pipe tested at. They said they didnt know and obviously didnt care. If you need to pass any sound tests Dr. D is the way to go.

I believe you are mistaken about that. CHM has Db cartriges which you can install in the muffle to meet the 96db requirement.

[want2ride]

Rangers don't monkey w/the 4-strokes where I ride. I did get sound tested on a CR250 once.

Now about the pipe. Today I rode in various conditions w/the CHM pipe, then

swapped back to stock to get a feel for the changes.

My seat of the pants dyno:

I could be wrong, but feels like

LOW END: CHM Pipe is better

MIDRANGE: Stock pipe seems to have more torque

TOP END: CHM Pipe feels like it pulls harder, maybe just louder??

Best jet = 168 both pipes(tested 170 and 172)

Best Low End = > 2.25 turns w/CHM, 2.0 Stock.

What results are you guy seeing?? Anyone actually dyno their bike?

Note, the CHP pipe has a spark arrestor installed during this test than can

be removed and I will at the track next time.

[motoxguru]

Seat of the pants dyno's are the only ones that matter, IMO.. Do you have the SM1 pipe?

[Wayward Son]

the SM1 doesnt come with the spark arrestor.can be added........

im pretty sure he has the regular p4r.

[want2ride]

Yep, the P4R. It has a removable spark arrestor. I'm going wind on it Sunday a bit more...

[howdydooty]

I know this is a very very old post but anyone know how to get a hold of CHM. I would like to get a spark arrestor and can find nothing about them. All I have found is that they went out of business about 8 or 9 years ago.

[Ron Hamp]

yes there gone .

[howdydooty]

Dang anyone know if u can put or manufacturer an fmf to fit or any other. I really like this exhaust would like to keep it plus I don't have the 400 to 500 dollars to put on another at the moment. Thanks again for your input.

[H4L]

Yeah - I remember when I first picked up an 05 model the CHM exhausts were popular in my area & a co-worker at the time swore by them.   They have been long gone & your going to have to fabricate a spark arrester screen of some type.  I'd measure the diameter of the end cap orifice & try to find a current manufacturer that has a spark arrester screen assembly with as close in dimension.  I bought a used Yoshimura RS4 exhaust system on CL that came with a spark arrester screen that's removable at the end cap.   Just a thought hope it helps.   

[howdydooty]

Yes that does help thank u I will look into the size of the Yoshimura one had a buddy tell me the fmf one may not work.