Exhaust Drone Revisited RCA

Are you sure its the exhaust and not yor track? My RX1 has the same howl in the same speed range as my buddys apex and I believe it to be the ripsaw track. You might want to change to a predator or something

The drone (I experienced) is a coupled resonance between the exhaust and the track.

It only happens at certain speeds and it only happens with certain rpms from the engine and track. Take a note of your tack and speed. You'll likely see it only happens with specific combinations (give it a tiny bit of gas and before the track speed changes, the drone will often go away for example).

One solution is to install a clutch kit that shifts the engine rpms so the exhaust doesn't couple with track.

Another option is to replace the track with a quieter one.

Personally I've found very little drone (essentially none) with my 9837H144 track on my 07 RTX.

Another option that worked well on the 05 RX-1 sleds is to simply install 144 studs. The increased track weight changes the track resonance and this gets rid of most of the issue.

Another change that tends to help temporarily is to install new hyfax. Unfortunately this fix doesn't stay quiet for long.

The bad news is there seems to be little consistency on what works on one sled and doesn't work on another. My guess is tolerances on track weight, track thickness, clutching springs/weights/helix, rider weight, rolling resistance (snow conditions, setup), etc. all play a factor is making some sleds resonate and other ones quiet.

You might be onto something by using resonators to cancel certain frequencies from the exhaust. If you can reduce the particular frequency that is coupling with the track you should be in great shape (but tuning it so it is right on could be difficult). At the same time, I do know that it is often the sleds with quieter exhausts where you notice the extremely bad resonance at certain speeds and engine loads.

Good luck and let us know what works/doesn't work.

I woud start with the track. I put aftermarket pipes on my '06 Apex, and the drone is still there, and didn't change at all. I know that it's the track.
Kill two birds with one stone. Switch to a Cobra or Free Ride, or something. The Rip Saw's in my oppinion don't work well in a broad range of conditions. If you're not riding on a perfecty groomed, hard-packed trail, you're loosing traction.

So - rca1070, did you finish making the inserts like the Corvette idea and try them? How did they work? Can you post some pics if they worked?
I have a '07 Attak and cannot stand the drone. Earplugs inserted well into the brain still does not eliminate it.
I have made one insert, now I need to make another mirror image one, stuff them in and try it out.
Has anyone tried Dynamat products on the top of the tunnel under the Seat and Tank? Seems like that might help also.
I love everything about the sled except for this problem. Gotta solve it!

Your only 2 posts on this site have been complaining about your RTX. Is there anything you like about the sled?
Honey and Vinegar, which catchs more files?
I found the majority of people on this site very friendly and helpful if you approach your questions in a nicer manner. Just my 2 cents ,which you might not want to hear.

jlemieu1 said:

Your only 2 posts on this site have been complaining about your RTX. Is there anything you like about the sled?
Honey and Vinegar, which catchs more files?
I found the majority of people on this site very friendly and helpful if you approach your questions in a nicer manner. Just my 2 cents ,which you might not want to hear.

Click to expand...

Will post the picks of what I made after I ride this weekend and see if they actually did anything.
In reply to Jlemieul's comment of anything I like... Of course there is, but one should always be free to comment or question things that could be done better. How about the poor MPG and small tank. Would people not like to step that up. I see lots of posts on that as well. Don't add comments without solutions.

drone

Quiet ride ice ripper cured the drone on my 06 rtx, now has an addicting sound

quiet ride

what is quiet ride ice ripper? never heard of it.

IMO its not the track....its all about the exhaust.

I have a predator on my sled and still have the drone...i also run two sets of wheels,and changed out sliders ect ect...

another reason i dont think its the track is the fact that every other sled out there,DOES NOT have the drone...and there are plenty with ripsaws.

I rode a new nytro last weekend at demo days..NO DRONE....those are alot quieter sleds....

SO i come to the conclusion its either the exhaust or the motor that REVS much higher in combo with the exhaust....

when i did my DONUTS@ the Y pipes.....i saw that the Y pipes are BOLTED directly to the tunnel...and IMO this could be the culperit....I would bet the exhaust PULSES being pushed out of the system,at certain RPMS,makes the Y pipes vibrate enough to resonate thru the tunnel.

anyone who thinks its the track....i can guarantee its nothing to do with track....its all about the exhaust...and how its mounted to the TUNNEL IMO.

Id like to mount the Y pipes with some sort of urethane rubber mounts or something....to see what it did.

this is why i have been wearing my mp3 player for 3 seasons.

Dan

quiet ride

ice ripper with nobs built in where idlers ride, Cat was first to have this feature. Every window open, clipped every third, very smooth ride and really hooks. No need for external studs.

I agree, with rockerdan, was riding with a former Apex owner Sunday, we were coming to that same conclusion, resonance. Seems that due to certain engine speeds there is a resonance with the sled. It's really annoying sometimes.

Overall I would like this sled to be wayyy quieter, but I'm not aware of a "quiet exhaust" option. Aftermarket exhaust are just lightweight and louder, which shuts trails down.

Rockerdan,

Scary, I was thinking the same thing about the exhaust mounting. Coming from the automotive engineering field, the Powertrain and Exhaust both need to be isolated from the chassis to eliminate NVH (noise, vibration, harshness).
No wonder the oil tanks crack and guys are having issues with dash clusters, wiring, etc. and I'd bet a few beers Exhaust Donuts...
Vibration and harmonics are DESTRUCTIVE !!!
My hands go numb after riding at 20 mph around 5000 rpm.

Dan, if you need help with that isolation experiment, I'll be glad to offer a hand... I have free run of the Full Power Performance machine shop in Ellicottville.

Go for it, sounds like a business opportunity.

You guys are missing the flex mount that Yamaha is using in the y-pipe mount.

It is a flexible piece of curved metal or effectively a spring. The back end of the exhaust is also isolated, this time through rubber isolation mounts.

I do now agree with you guys that the newest resonance I'm experiencing with my Apex is definitely mostly the exhaust. I'm not sure if this is the same as what you're experiencing, but I'm wondering if a baffle in my muffler or something has come loose. At around 5000-5500 rpm there is a very sharp razzing sort of buzz coming from the exhaust. I think the left side is louder than the right also (just the buzz sound, not the overall tone).

It goes away at higher or lower rpms, but I also think my idle sound levels are up a fair bit too.

While sledding on the weekend I compared my RTX to an Attak and to an 06 Apex. Mine was the loudest. The Attak was incredibly quiet compared to mine.

Are all Attak's quiet compared to our short track sleds?