FMF Stealth silencer update!!

[AZRickD]

I was in the shop (monkeybuttparts.com) when the FMF arrived for F_G's bike.

It looked like a 4T can, only smaller. Maybe mid way between.

A 6 dB drop in sound pressure is significant. A 3dB drop is half. Another 3dB is half again (is that how that works? ).

The only think I'll hear when F_G rolls up is chain noise.

 

[PEB]

I am pretty sure that the sound level would drop by 6dbm. DB is used several different ways. As a measurement (dbm)like on the FMF pipe or in other cases where as you mentioned a 3db reduction is half. It would be quite a feat if FMF made a pipe that muffled the sound by 75%

 

[SideshowBob]

My buddy has an '05 DE250, I can certainly check and see if it will fit or see what might need to be done to make it fit.

That would be great, but no rush.

 

[iancp5]

The only think I'll hear when F_G rolls up is chain noise.

Don't worry no matter how good the can is there'll be plenty of noise coming out of the front pipe walls. Still a welcome drop as it should be very quiet at a distance. It's just that close up you get a lot of noise through metal. It always surprised me how quiet my 300 was from just 20 yards while sat on it was a different story.

 

[F_G]

Actual sound and perceived noise are definitely two different animals. I rode the bike down the street and my son said when I was 3 houses away he could no longer hear the exhaust just the chain slap. So it cuts db in the J1287 test (not a real good representation in my opinion, but at the moment it's the only repeatable test standard we have) plus it minimizes perceived noise which is much more important to me. In my opinion well worth the money.

 

[Skidad]

At some point I'll coat the back of my carbon fiber pipe guard (or actually right on the pipe itself where the guard rests which would stop corrosion/rust) with a high temp rubber coating. I believe this would quiet down some of the pipe bang noise. Need to do a little research first into coatings but that shouldn't be to difficult.

I've also got some ideas about the really irritating chain slap noise as well to work on. That really bugs me. We will see.......

 

[F_G]

At some point I'll coat the back of my carbon fiber pipe guard (or actually right on the pipe itself where the guard rests which would stop corrosion/rust) with a high temp rubber coating. I believe this would quiet down some of the pipe bang noise. Need to do a little research first into coatings but that shouldn't be to difficult.

I thought about trying the poly urethane they use for truck beds, just not to sure how heat resistant it is.

I've also got some ideas about the really irritating chain slap noise as well to work on. That really bugs me. We will see.......

I put a strip of neoprene under the chain guide on top of the swingarm on my KTM and it quieted it down considerably.

 

[rpduc]

Wow 85+ dB. That's what I like to hear. Or not hear...

The last time my MC was checked it was about 92dB so I guess I could expect a similar reduction. Thanks for the report F_G.

Now how about fitment on that "old" DE 250?

I have grinders and welder to make it fit my '05 MC but it would be great if it fit right up.

 

[F_G]

As soon as I can get my 300 in close proximity to his 250 I'll let you know.

 

[F_G]

Q Stealth ride report.

-Very quiet

-Had to actually rev it a few times on some rocky descents to see if it was still running

-Didn't notice any power loss using my very sensitive butt-dynometer

-Had many people comment on how quiet it was

-I like it

 

[forgiven]

I have an 01 300 and does anyone know if this can be modified to fit or will it fit straight up? I REALLY want one so any information would be great.

 

[slocalspode]

I think there are a few of us waiting for that report.
I have no excuse except for being lazy. Heck I only
live 8 miles from FMF. I just need to take some time
off work, load my bike in the truck and drive over there
for a test fit. That is. Once the piggie bank swells with
enough cash to actually buy one if it does fit.
If I go, I'll take both a 99 EC250 and an 02 EC300.
The 99 has a Mesico pipe and the 02 has an FMF Gnarly
on it.
I'll report back if it fits either, neither or both bikes.
Jeff So. Cal.

 

[F_G]

Sorry guys, my EC300 and his DE250 have not been in close proximity yet. Next weekend at the race our club hosts we'll take a few minutes and see what it looks like.

 

[forgiven]

It would sure be great to find out that it did or did not fit an older 300.

 

[rpduc]

I just talked to Mark at GF and he said the mounting tabs on the can are different so it sounds like a bit of cutting and welding would be required to fit these things to pre-'07 bikes.

Mark also said he would try to get some pics posted of how the silencer doesn't fit the older bikes. Hopefully we'll be able to see how much is involved in modifying it.

 

[forgiven]

It would be real cool if FMF stepped up.

 

[F_G]

Had my '08 and my buddies '05 in close proximity this past weekend and it will take a bit of modifying to get the Stealth mounted to pre-'07 bikes. The mounts on the earlier bikes are offset on the subframe and '07 and newer are in a straight line. Stopped there and didn't check if the stinger on the pipe and the silencer were even close. Sorry guys.

 

[forgiven]

I guess the dbsnorkle is calling me then...it looks so stupid too...meh

 

[Brian VT]

I guess the dbsnorkle is calling me then...it looks so stupid too...meh

I can't see mine at all when I'm riding, well, except at the last race when I whacked a tree, that I thought would give, with my left handguard and woke up on top of my bike looking at the dbsnorkel. Yeah, it's ugly. LOL

 

[rpduc]

The mounts on the earlier bikes are offset on the subframe and '07 and newer are in a straight line.

If that's ALL it is then it would be pretty simple to cut and reweld or make new tabs. Actually not a big deal to bend or cut and reweld the inlet to accommodate a slightly different stinger angle either. I'd like to see some pics first, but I might just order one up to see for myself.

I've thought about the dB snorkle too. I don't care soooo much about the ugly part, but more crap hanging there is not so appealing.

Brian, what does your bike blow in sound checks with the snorkle?