Ultimate Sidewinder Muffler Decibel Test

[Beerman]

UPDATED Oct 20, 2017 - This is the revised-revised follow up to my first test attempt and NOS-Pro's original test of the Evo Magnum where he was able to get a DNR officer out to verify his results.

This "Ultimate" test includes a pretty full range of mufflers - Hurricane's Hindle thanks to Dave Marshall's generous offer to ship one out for the test, The TD Stock Modified thanks to Ben's generosity in sending me one and Blue Dave for letting me borrow his brand-new TD TurboForce. With 5 excellent mufflers (and the stocker), I tested idle and 2500 rpm (as per DNR test criteria) - but also 5000 rpm and WOT per several requests. I know that without the engine being under real load the 5000 rpm and WOT results are not that meaningful - but they're better than nothing.

Some quick research turned up 2 different DNR noise tests that many of us in the U.S. may encounter -

• Wisconsin and Michigan both test @2500 rpm, 13.1' from the center of the sled, 48" from the ground, 88 dB maximum
• Minnesota and Maine* both test @2500 rpm, 50' from the center of the sled, 48" from the ground, 78 dB maximum.
  • *As of March 9, 2017 Maine also requires any muffler to have the official S.S.C.C. stamp for visual inspection w/o the need of a dB meter/test. See http://cs.amsnow.com/sno/b/news/arc...d-public-hearing-on-two-snowmobile-bills.aspx for more info.

I'm sure there are others, but these are the 2 sets I settled on.

This time around I bought a real dB meter, and it's a good thing I did. The BAFX3370 is inexpensive ($18) but had good reviews on both Amazon and other places - "while it's inexpensive, it's fairly accurate". After comparing it to the app on my iPhone that I used in the last test, the meter is obviously way better. It's far more sensitive and also more consistent.



Here are the results:

*See additional/new note above on Maine.

The net of the test is that all mufflers "should" pass both DNR tests based on the results I found - but it's not an official dB meter and I'm no DNR officer. Results on a different day, or done on a cement parking lot could be much different. They could also be lower with several inches of the beautiful white stuff covering the ground and making us all happy. The Hurricane, SanDale and TurboForce are borderline in the 13.1' test - BUT - I'm convinced I picked up some amount of track noise too, I should have put the track on the ground for the 2500 test, there are a few times where the track starts to spin and make some noise as I fluctuate between 2500-2800 rpm.

The 5000 rpm and WOT results are what they are - I know the tone and volume would be a lot different under load and who knows how much noise the track is contributing to these readings.

The sound quality isn't great because of the wind noise, but I have a pretty good camera, so take it for what it's worth.

Whew.

 

[ROCKERDAN]

Wow great work here. That video is alot of work editing all that together I know. Nice job.

A cool thing would be to take all that footage, and clip together each muffler doing each RPM into a direct play. So you would hear idle, going from quieted to loudest in succession, and then engagement, and then 5000, and the WOT....but with each muffler clipped directly together into a video with no stopping in between you would instantly hear each sound change.

You have all the great footage already, and all from same distances....it sure is a nice controlled atmosphere you used and would be amazing to hear them all back to back to back all else being equal.

Only thing i truly wish is that you has a STOCK MODDED into this mix for this type of back to back video all clipped together.

Fantastic work here, and thank you VERY MUCH for taking the time to do this, I know these type of tests and posts and video editing can take MANY hours of time, so I for one appreciate your great effort here.

Dan

 

[NYTurbo]

Good job.

 

[Beerman]

Thanks for the compliments - and Dan, that's a FANTASTIC idea and iMovie makes it easy enough. Replacing the video file on YT now.

 

[silverram323]

Beerman, thanks for taking the time to do this study. I would like a tune and exhaust and I don't want any tickets. Like you I also live in Minnesota, I'm up in North Branch.

Do you think the sound read out would be different on the snow as it would reflect sound vs grass absorbing it?

The track for sure adds DB, it was very noticeable in the video. I'm wondering if taking the belt off for 2500 / 5000 rpm would change it much?

 

[Beerman]

The video is now updated with the order that Dan suggested - much better.

 

[Beerman]

Beerman, thanks for taking the time to do this study. I would like a tune and exhaust and I don't want any tickets. Like you I also live in Minnesota, I'm up in North Branch.

Do you think the sound read out would be different on the snow as it would reflect sound vs grass absorbing it?

The track for sure adds DB, it was very noticeable in the video. I'm wondering if taking the belt off for 2500 / 5000 rpm would change it much?

I "think" it'd be the same on snow as on my wet lawn, but snow has a nice way of quieting everything down. My guess is that you won't get ticketed for noise with any of the 3. And I did think about removing the belt, but w/o some load on the engine it won't move nearly as much air and thus a lot less sound.

 

[silverram323]

I like the updated video.

 

[HURRICANE]

This thread started by beer man is an awesome example of why I like ty4stroke. Two thumbs up and a great big thank you.

 

[Beerman]

Dave, having guys you like you, Ben, Dale, NOS-Pro, Shagman, RockerDan and a host of others sharing valuable info on here makes it the best forum I've ever seen.

 

[blueironranger]

Does that meter have a "A-Weighted" setting and "Slow" response setting? That's the setting used for actual testing trail side. It makes quite a difference, Normal setting on my calibrated digital Radioshack meter gave higher readings than when using A-weighted and Slow response, sometimes 4-5DB higher. My Phazer with a Skinz Ultra-Q was in the low 90's on the normal setting and 87-88 on the A-weighted Slow settings and I got check in MI and it just barely passed.

 

[Beerman]

Does that meter have a "A-Weighted" setting and "Slow" response setting? That's the setting used for actual testing trail side. It makes quite a difference, Normal setting on my calibrated digital Radioshack meter gave higher readings than when using A-weighted and Slow response, sometimes 4-5DB higher. My Phazer with a Skinz Ultra-Q was in the low 90's on the normal setting and 87-88 on the A-weighted Slow settings and I got check in MI and it just barely passed.

Interesting - It measures in dBA only if that's what you mean by "A-weighted". It doesn't have a fast or slow sampling setting, it does it 2x/second. Is that fast or slow?

https://www.amazon.com/exec/obidos/ASIN/B00ECCZWWI/ezvid02-20

 

[Turbo Dynamics]

Beerman, your last video at 50 feet distance is my favorite. That was very well executed.
Overall, superb job !

I again want to point out the obvious, the Super Quiet wasnt new. I expect 2 db quieter if it didn't have a season in it.
And on your first short distance test, you had it perfect on every run except the super quiet. You held the throttle longer on that run with more track speed which will create a larger spike in DB
But on your long distance video, you got the timing perfect on every run and the numbers made sense.

You want a job at TD ? LOL !!!

 

[blueironranger]

Interesting - It measures in dBA only if that's what you mean by "A-weighted". It doesn't have a fast or slow sampling setting, it does it 2x/second. Is that fast or slow?

https://www.amazon.com/exec/obidos/ASIN/B00ECCZWWI/ezvid02-20

DB-A is A-wieghted, with 2x a second it is between Fast and Slow repsonse. Fast is 1/8 a second sample average and Slow is a 1 second Average. The Slow setting usually gives slightly lower numbers as it "averages" a longer length of time eliminating spikes. If anything with the faster response time your readings may be a 1-2db high but being on the high side gives you a bit of fudge factor.

 

[**sj**]

thank you beerman for your diligence and efforts...is it correct the only aftermarket exhaust that is used as of this test is the TD super quiet????