Sound Testing on Piped Viper

xsivhp

xsivhp

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Eau Claire, WI
Well, I did it - used the new astm standard for snowmobiles and test my hauck triple piped 02 viper (same style as the cpr units I believe) - on the concrete slab along side the house and out in the middle of my yard on grass.

The standard I read stated the probe be placed 4 meters away from the centerline of the vehicle and 4 feet off the ground (not sure why they mixed units there, but I've seen dumber things) with the sled running between 3750 - 4000 rpm for no less than 4 seconds.

I warmed the sled up and ran it at 4050-4100 (closest I could get to 4000) the result were interesting:

on the slab alongside the house: 89 db

in the yard: 85 db

They sound great, I'm really tempted to throw them on the 04 except for 3 things: afraid of the dcs light problems, afraid of mid range burn down and afraid of killing myself. lol :)

It did feel great ripping across the back yard though! :D
 
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Just be careful because the DNR says you cant modify your exhaust to make it louder than stock.
Not sure what the stock DB on a Viper is, but with how much the DNR is cracking down on snowmobilers you can bet they will try to bust you for every little thing they can.
Id love to put a can on my sled so that it has more of the 2-stroke "braaap" to it, but where I ride you can bet it wouldnt be long before I got busted.
 
I've actually read that the current financial state of our state of WI means that there won't be a lot of enforcement of snowmobile regs this year - Ive also read that the night time snowmobile law is dead, as it hasn't been renewed. In other conversation I've read that they cannot ticket you strictly on the basis of having a modified exhaust or because it "sounds loud". If they ticket you for having a modified exhaust, they should be writing ticket to 98% of Harley Davidson owners. They can't selectively prosecute just one group for it. And for noise levels they now need scientific evidence of the level of noise your sled is making. Has anyone else heard any of this?
 
the law in NY is 90 DB. We got pulled over last yr and the Madison county sheriff had no idea what the legal DB limit was and still gave my buddy a ticket for a trail can. he got it thrown out of court. I might not have the right attitude but until they start ticketing Harley's I'm running a can on my sled. :2strokes:
 
xsivhp said:
I've actually read that the current financial state of our state of WI means that there won't be a lot of enforcement of snowmobile regs this year - Ive also read that the night time snowmobile law is dead, as it hasn't been renewed.
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My brother is a member of a snowmobile club here in southern WI and at the meeting last weekend the topic of the speed limit came up. From what they told him, the 55 mph speed limit will be a law by next year and will be in effect for the next 3 years.
sxivhp said:
In other conversation I've read that they cannot ticket you strictly on the basis of having a modified exhaust or because it "sounds loud". If they ticket you for having a modified exhaust, they should be writing ticket to 98% of Harley Davidson owners. They can't selectively prosecute just one group for it. And for noise levels they now need scientific evidence of the level of noise your sled is making. Has anyone else heard any of this?
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Sounds like BS to me. Every year in Eagle River when the Derby is going on the DNR is out in force checking exhaust. They just sit on the side of the trail with DB meter and if it reads that you are too loud, you get a ticket. Everyone knows what a sled with pipes or a can on it sounds like, so it doesnt take a rocket scientist to know who had modded exhaust.
I agree with you about the Harley owners and I think that is total BS too. Ive talked to a few cops about this and the answer I was given was that there are so many Harelys out there with loud pipes that if the cops busted them all that they would be so busy writing tickets they wouldnt have time to deal with the "real" crimes. I then made the comment, "then I guess I can just run straight pipes with no mufflers and no cats on my truck then". He kinda chuckled and was like, "you can, but you will get a ticket if you get caught". I agree with you that its a BIG double-standard. Things are changing though. Harleys arent that loud when they come from the factory, people make them loud because they think its cool and there is this thinking that a Harley is supposed to be loud. You know, the old Harley adage that if it doesnt vibrate like crazy and isnt loud that its not cool. However, even a lot of the aftermarket pipes arent anywhere near as loud as they used to be. Even still, theres nothing stopping someone from knocking out the baffles or removing the sound deadening material inside the muffler and making it loud.
One thing though is that Harley riders can get away with it because you arent going to get the roads shut down because of noise, but many trails can and do get shut down because of things like noise. Not sure if you are aware of it or not, but riding on the public trail system is a privledge, not a right. Any landowner can say at any time that he or she does not want the snowmobile trail to cross their property for any reason.
 
Octane said:
.....Not sure if you are aware of it or not, but riding on the public trail system is a privledge, not a right. Any landowner can say at any time that he or she does not want the snowmobile trail to cross their property for any reason.
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Totally aware of this - if I put the pipes on I guarentee you I wouldn't be flying down the trail WOT at 2 am in areas where there are houses.

Just seems like such bs - I bet the pipes on that Viper are no louder than a Firecat. They really aren't that loud IMO.

I do appreciate open trails though, too.
 
;)! - that is interesting - I was going to do the same thing with my sled as I have a Hauck silencer on it - I wouldn't think it would be louder than your pipes - I would also think the db on snow would be a little less than being on grass or at least the same
 
depends if it is hard pack or fluff. the snow on the ground would definitely absorb some sound that's for sure!
 
I hope you didnt get the impression that I was trying to preach, I wasnt. I would just hate to see someone spend all that money for pipes, then take the time to tune their sled to run with them only to find that they cant trail ride their sled with that setup.
Do what you gotta do, just be aware that if you get caught the DNR or local po-po will most likely give you a ticket.
 
how did you get the revs to 4000. if you had the track up i dont think you have an accurate reading because you sled will make more noise under a load.
 
I had the track up on a stand, warm it up good and when I did the test I held the brake per the test parameters. The readings were consistent per my certified sound tech - my wife! ;)! lol

Not worried about you being preachy - pipes were on the sled when I bought it - just that they sound so nice it kinda sucks to have to take them off - bu I already bought the stuff to do it.

Bottom line is that it's a free world, and not really up to myself or anyone else to say we can or can't do something. That's what laws are made for.

I would think the piped viper makes more power at a lower rpm than mine does WFO though. I may keep them on for the first ride just to take it for a spin that way. We usually ride up around arbor vitae / woodruff , Boulder junction area .... time will tell though I guess.

I just thought someone might be interested ... and maybe someone would know what the actual rules are ...
 
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