How can I make my bike quieter?

[gtsnowcrack]

I have a 2004 EC200 with a Gnarly pipe and stock silencer (FMF Turbine Core something or other) It has the LTR PV cover and LTR jetting kit. I race and noise is a problem for me. Even with a repacked silencer I blow 96+ dB. Listening to the bike it seems like most of the noise is coming from the front of the bike but the pipe is seated well on the cylinder. Anyone have any experience/suggestions?

 

[jeffd]

A couple of things...

1. A skid plate reflects noise and increases db reading.

2. A carbon fiber pipe guard dampens noise from pipe and reduces db reading.

3. Silent sport packing helps a tad. This looks like stringy cotton versus the fiberglass matting that comes in the silencer stock. What did you use when you re-packed it last?

4. The db snorkel looks interesting. Have you checked it out? www.thedbsnorkel.com

5. The oem silencer that comes on euro models is noticably quieter - it meets ISDE spec of 94 dB. Unfortunately it lacks a spark arrestor. Erik Kangas recently took delivery of his '06 and had to add a spark arrestor - it was a Cobra Sparky spark arrestor made to fit an FMF silencer for a CR250. The part number is 9157. A few bikes have been recently delivered into the U.S. with this silencer - it probably wouldn't be hard to find a "take off".

-----

I might have a euro silencer in my garage - are you interested in it? I'll take a look tonite.

- jeff

 

[gtsnowcrack]

1. Skid plate, I was thinking about some some foam and weatherstripping to damp the noise.

2. Might have to go pick up a CF pipe guard. Also I think I was told that the pipes on the european GG's were double walled? And were quieter?

3. I'm pretty sure the packing was the sheet not the stringy stuff.

4. Seen the dB Snorkel, there's a couple guys around here that have one... Actually dropped one guys CR500 a good 8 db to pass sound for a race. I'm just not sure if it will help because most of the sound is coming from the front of the bike not the back. I'll see if I can borrow one and test the sound difference.

5. Definitely be interested in trying a Euro silencer, but again, I'm not sure if that's where the problem was.

It's just so irritating! I know so many people with KTM's and their bikes are in the 80's sound wise and I feel like a complete jerk with my loud bike.

 

[MattR]

Just curious... I've seen the header wrap tape used on 4T bikes to get a better internal chamber temperature (and less accidental burns to yourself). Could this be used on the 2T bikes to provide some sound absorption?

It would also serve to maintain pipe temperatures which in-turn influence internal pressure. Of course, the 2T pipe shape does not lend itself to easily wrap it with tape. I've been curious about the idea for a while. The cost of the tape is holding me back from trying it (about $50).

Here is some from Helix to give you an idea (50in x 1in). There is also a 2in width.

 

[Brian VT]

I know so many people with KTM's and their bikes are in the 80's sound wise and I feel like a complete jerk with my loud bike.

+2. The KTMs are quiet. I'd love to get my EC down in that db range. I won't give up my Gasser though. I love it more every time I ride it and it has squeaked by the sound checks so far.

 

[gtsnowcrack]

I actually have a pack of exhaust wrap from DEI that I was going to use at the last race for just incase I didn't pass. It's a 2"X50" roll. I haven't put it on yet because my pipe needed some dents removed.

I'll give a report once I put it on and see if I can borrow a sound meter.

Just curious... I've seen the header wrap tape used on 4T bikes to get a better internal chamber temperature (and less accidental burns to yourself). Could this be used on the 2T bikes to provide some sound absorption?

It would also serve to maintain pipe temperatures which in-turn influence internal pressure. Of course, the 2T pipe shape does not lend itself to easily wrap it with tape. I've been curious about the idea for a while. The cost of the tape is holding me back from trying it (about $50).

Here is some from Helix to give you an idea (50in x 1in). There is also a 2in width.

 

[Cruiser]

Be careful with the pipe wrap! It works but it will kill the pipe. It keeps heat in and makes the thin pipes brittle and they are prone to blow out type failures. I've seen this on drag cars and have heard its worse with the thin 2stroke pipes. You could try getting it ceramic coated. Also I have a dbsnorkel and it works well, just looks goofy. Use the foam under the skid plate and modify a ktm stock silencer to fit your bike. It will be quieter. I have a PC ISDE silencer on my 97 and its a deeper sound. I had to modify it so it aint perty but its on.
Good luck,,
Steve C

 

[Magellan]

5. The oem silencer that comes on euro models is noticably quieter - it meets ISDE spec of 94 dB. Unfortunately it lacks a spark arrestor. Erik Kangas recently took delivery of his '06 and had to add a spark arrestor - it was a Cobra Sparky spark arrestor made to fit an FMF silencer for a CR250. The part number is 9157. A few bikes have been recently delivered into the U.S. with this silencer - it probably wouldn't be hard to find a "take off".

My 04 EC300 regular gets a 91 or 92 dB when I go racing. I have yet to repack it.

 

[WoodsRider]

Back in February, at the Snowrun Enduro, my '01 XC300 tested at 99 decibels, with the stock FMF pipe and stock FMF TC2 silencer. After that I repacked the silencer and installed a Motowest pipe with an E-line CF guard. In April my club did some sound tests to get read for our hare scramble (NETRA requires sound testing at all events) and my bike measured 93 and 94 decibels.

In May I installed a dbsnorkel. When I first cranked it up I wasn't very impressed with the sound reduction. Then I isolated the engine noise from the exhaust and could definitely tell a difference in tone with the dbsnorkel installed.

There's quite a bit of engine noise reflected off the skid plate and I don't like using foam. Tried insulating it with some garden hose, but was afraid this would allow the skid plate to move around so I removed the hose. At the last two enduros, Somers Fun Fun Fun and Little Rhody, it tested 87 and 88 decibels respectively.

 

[MattR]

At the last two enduros, Somers Fun Fun Fun and Little Rhody, it tested 87 and 88 decibels respectively.

Were these low numbers due to the dBSnorkel or the garden hose/foam isolation on the skid plate?

 

[WoodsRider]

Were these low numbers due to the dBSnorkel or the garden hose/foam isolation on the skid plate?

Matt - The reduction has all been due to the dbsnorkel. I didn't like the garden hose so I never ran my bike with it installed. I don't run skidplate foam anymore either. If there's any power loss from the dbsnorkel, I certainly don't notice it. In fact this year my results have improved and I'm coming home with more hardware.

NETRA has a 96db limit for all events. They also have a "fudge factor" to account for meter accuracy. There are a few bikes pushing this limit, particularly in hare scrambles. I'd really like to see the limit lowered even further.

 

[Mark Tracy]

Have you conserided a FMF "Q"?

 

[Nick]

On 05 and newer so i would imagine 04 also you can use an FMF Q from a 99 KX 250 by cutting a small amount from the stinger on the exhaust.

 

[gtsnowcrack]

UPDATE! We wrapped the pipe last night with header wrap and it made a HUGE difference. The tone is a lot lower and just quieter in general. Going riding this weekend, I'll let you know if the pipe blows up.

Note: Wraping the pipe was very time consuming and fustrating. Material used: Design Engineering Inc. 2"X50" wrap and 10 SS ties

As for the FMF Q, never thought about it because there wasn't one for the Gas Gas and I was mostly concerned with noise from the pipe. However I'll probably look into the dBsnorkel for some added noise reduction.

 

[MattR]

UPDATE! We rapped the pipe last night with header wrap and it made a HUGE difference. The tone is a lot lower and just quieter in general. Going riding this weekend, I'll let you know if the pipe blows up.

Note: Wraping the pipe was very time consuming and fustrating.

Can you post a pic of your setup? I'm interested in what it looks like. Curious how much of the pipe you wrapped up.

 

[mattmax]

quiet bike

Have you looked into the FMF "Q" silencer? I know everyone will tell you they don't make one, but they said that about my 06 KTM. I called FMF direct and they did. There is also a Q2 and "titanium Q something"
I bought a Q for my 06 300xcw because the KTM's don't come with sparkies. At least as quiet as the stock and I believe they rate it to be a min of 94db, and I read a guy claim he had his down to 88dB, but I'm not sure which "q" he was using and what the difference in the three are. One may be for 4 strokes. You'll have to call FMF like I did. No one had the 06 KTM 300except FMF, and if they make a Gas Gas, you know no one has it but them. $160, $12 shipping for the basic 2 stroke Q. Not sure about the other ones.

Problem is I don't know where i put the number and I couldn't find it doing a net search. I may have gotten it when i called Pro Moto Billet about their rivet on spark arrestor caps. Kind of vague, I know, but worth a try.

FORGET EVERYTHING I JUST SAID. TALK ABOUT COINCIDENCE. I was just handed an 06 FMF catalog that came in the mail today. They don't list a "Q" for the ec 300, but they have the "q" for the 450 4 strokes and for the quads, and list several different pipes and silencers for two stroke GG's. It would be worth giving them a call to see if they have one that would fit with minor mod or enough calls would get them motivated to manufacture more GG parts. Phone # 310 631 4363

 

[webmaster]

Just an FYI - Hyde Racing is now a sponsor of this site; They are importing copolymer skid plates & guards etc from Hyde Development (South Africa) The material is much "quieter" than aluminum - absorbs sound. And it bounces back when it takes a hit.

jeff

 

[(F5)]

I’ve wrapped pipes for roadrace bikes for heat retention, but man did they sweat & rust. On a dirtbike it would be worse, almost like you’d need a quick release cover & remove it before you load it on the truck.

Perhaps you could lay some fibreglass as an experiment around the exposed areas of the pipe (spray with silicon first) then cut to make in 2 halves. Then run a bungee around it. The pipe in the larger areas would be cool enough for it to survive I reckon.

The next step would be make out of carbon matting with high temp epoxy resin & make some better quick release clamps, or a decent bungee arrangement.

 

[gtsnowcrack]

I’ve wrapped pipes for roadrace bikes for heat retention, but man did they sweat & rust. On a dirtbike it would be worse, almost like you’d need a quick release cover & remove it before you load it on the truck.

Perhaps you could lay some fibreglass as an experiment around the exposed areas of the pipe (spray with silicon first) then cut to make in 2 halves. Then run a bungee around it. The pipe in the larger areas would be cool enough for it to survive I reckon.

The next step would be make out of carbon matting with high temp epoxy resin & make some better quick release clamps, or a decent bungee arrangement.

Great ideas but I probably will be leaving the wrap the way that it is. My pipe's plated and I live in Arizona, rust is a strange and amazing thing here in general.

I like the Hyde skid plates/pipe guards but they don't make the combo piece for the 200 which is what I'd really be interested in considering my tendency to make large dents and bends in my pipe.

I'll look into the Q but I really like that I can probably try out the dBsnorkel from a local at one of our races and test the actual sound difference.

There was a guy at one of our races on a KTM 250 xcf? (four stroke, they have too many letters) Anyway he got a Q to meet sound and he couldn't pass the 96 dB sound test. Yes, he had repacked it recently. He ended up sticking a pine cone in the end to pass tech (no joke) and he had a very nice piney odor everytime he went by. I think he ended up top 10 so apparently it didn't hurt him too much!

So with that in mind I'm really nervous about spending $170 to make my bike quieter with no guarentee's. If my bike isn't quieter are they going to take the silencer back? Probably not, and then I'll have two silencers that do the same thing...

 

[gtsnowcrack]

Oh! Our camera's on the frizt so I have to borrow the work one, I'll try to get pictures up today, especially before I add any performance enhancing dents...