What to do to minimize/eliminate track howl?

[4strokeluvr111]

Jim,

I saw a post recently that got me thinking... It was questioned (not proven mind you) if the resonance, howling, drone... might be worse within certain helmets. This sounded interesting and I wonder if there might be something here to look into?

Have you been using the same helmet throughout your attempts to eliminate the annoyance?

It has droned with me wearing two different helmets. Couple of weeks back on a daytrip me and a friend (800 Doo eTech) switched sleds. No track drone to speak of and the first thing he said about mine was the "noisy track". My son noticed the drone on my 05 right away and confirmed it was a bit worse on my 14.

 

[MikeWalters]

3-4 different types of foam. Plastic, wood and aluminum strips. Glued or bolted on. When you say "plastics off" do you mean the front covers?

Changing the resonant frequency is a little different than what you have tried. Example: Plastic, wood and aluminum are too light to be effective (essentially dead weight changes resonant frequency more dramatically), and foam is an acoustic absorber, not a dampener. It is possible that at a certain speed and engine rpm that the tunnel is at its resonant frequency (the frequency at which something vibrates very easily). The Yamaha "performance" dampers would not help this at all IMO, they are not designed for this type problem.

There is something you can try but if It does not help, it will be difficult to remove. I have successfully used this in automotive applications countless times (including the cab of an enclosed side by side UTV that was VERY loud after closing in the cab). Similar to Dynamat, it is a viscoelastic damping layer and works AMAZING. http://b-quiet.com/products-3/b-quiet-ultimate/ These types of products very effectively dampen vibration and change resonant frequencies.

This type of material kills vibration, and vibration can cause resonance. The only way you could tell if this would benefit is to have your hand on the tunnel somehow and see if it vibrates when you hear the "howling". You would need to line the top of the tunnel with it. Does this make sense? Just throwing in my $0.02. Soundproofing is part of my day job.

Good luck, I know how much of a headache it can cause, literally (rode an apex with this drone before).

 

[icebreaker]

I switch to a back country track from a ripsaw and was surprised how much quieter it was. Not silent but better.

 

[4strokeluvr111]

Changing the resonant frequency is a little different than what you have tried. Example: Plastic, wood and aluminum are too light to be effective (essentially dead weight changes resonant frequency more dramatically), and foam is an acoustic absorber, not a dampener. It is possible that at a certain speed and engine rpm that the tunnel is at its resonant frequency (the frequency at which something vibrates very easily). The Yamaha "performance" dampers would not help this at all IMO, they are not designed for this type problem.

There is something you can try but if It does not help, it will be difficult to remove. I have successfully used this in automotive applications countless times (including the cab of an enclosed side by side UTV that was VERY loud after closing in the cab). Similar to Dynamat, it is a viscoelastic damping layer and works AMAZING. http://b-quiet.com/products-3/b-quiet-ultimate/ These types of products very effectively dampen vibration and change resonant frequencies.

This type of material kills vibration, and vibration can cause resonance. The only way you could tell if this would benefit is to have your hand on the tunnel somehow and see if it vibrates when you hear the "howling". You would need to line the top of the tunnel with it. Does this make sense? Just throwing in my $0.02. Soundproofing is part of my day job.

Good luck, I know how much of a headache it can cause, literally (rode an apex with this drone before).

Makes perfect sense Mike. In my past attempts, however lame they were, were the best I could think of. Do you think the B-Quiet stuff will stand up to the harsh environment of the tunnel? Why not do the sides as well? The stuff is only 1.6mm thick so it's not taking up any room. For $60 I'd give it a try.

EDIT - do you mean the outside top of the tunnel?

 

[ShootToThrill]

Think limbsaver on archery gear. I use rtv to dampen noises on eqpt at work. All pile of rtv half the size of a golf ball does the trick.

 

[4strokeluvr111]

Think limbsaver on archery gear. I use rtv to dampen noises on eqpt at work. All pile of rtv half the size of a golf ball does the trick.

Seems to be a good idea too. But will the RTV stay attached and where could one put 1/2 golfball sized pile of it on/in the tunnel?

 

[Redbeard]

I switch to a back country track from a ripsaw and was surprised how much quieter it was. Not silent but better.

I agree! I rode Agman57's Nytro with a 144" Backcountry track and it was leaps and bounds quieter than the 136" Ripsaw II on my Apex.

Makes me wonder if different track lengths and rubber durometer have an impact on noise.

 

[4strokeluvr111]

I agree! I rode Agman57's Nytro with a 144" Backcountry track and it was leaps and bounds quieter than the 136" Ripsaw II on my Apex.

Makes me wonder if different track lengths and rubber durometer have an impact on noise.

The Backcountry track has a 2" paddle. Too much for the all groomed trail riding that I do.

 

[tomanytoyz]

You can have your drive cogs machined close to perfect.ski-doo has some new drivers on there touring models to reduce NVH .

 

[MikeWalters]

Makes perfect sense Mike. In my past attempts, however lame they were, were the best I could think of. Do you think the B-Quiet stuff will stand up to the harsh environment of the tunnel? Why not do the sides as well? The stuff is only 1.6mm thick so it's not taking up any room. For $60 I'd give it a try.

EDIT - do you mean the outside top of the tunnel?

I was thinking outside top of tunnel, so exhaust right above it (which shouldn't be an issue). Not sure about the sides, I guess you could try a small patch and see how it holds up first?

 

[maim]

my brother was into stereo competition and he found an article by some kids where they used asphalt undercoating to get over 3/4 the effectivenss as dynamat. tested it on my truck when we did it and it did make a difference. maybe put that inside of the tunnel?

 

[Redbeard]

The Backcountry track has a 2" paddle. Too much for the all groomed trail riding that I do.

There is a 2" and a 1.75" paddle Backcountry. I should have mentioned that I rode a 1.75". It was much quieter than the 136" x 1.25" Ripsaw II in my Apex.

 

[4strokeluvr111]

There is a 2" and a 1.75" paddle Backcountry. I should have mentioned that I rode a 1.75". It was much quieter than the 136" x 1.25" Ripsaw II in my Apex.

I looked at Camoplast's website and only saw a 2". Must have not done something right to see only a 2" If memory serves it is a single ply track though.

 

[4strokeluvr111]

my brother was into stereo competition and he found an article by some kids where they used asphalt undercoating to get over 3/4 the effectivenss as dynamat. tested it on my truck when we did it and it did make a difference. maybe put that inside of the tunnel?

I was talking to a friend last night about spraying bedliner in the tunnel. Auto undercoating would be essentially the same I think?

 

[Redbeard]

I looked at Camoplast's website and only saw a 2". Must have not done something right to see only a 2" If memory serves it is a single ply track though.

http://www.tracksusa.com/Back-Count...9&browse=-47153&shopBy=-13144&catalogId=-3693

http://www.snowgoer.com/snowmobile-news/yamaha-announces-2013-fx-nytro-xtx-1-75/0209/