FYI
A turned down elbow welded on the exhaust doesn’t work........
Completely murders response.
A turned down elbow welded on the exhaust doesn’t work........
Completely murders response.
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Quiet 4 stroke exh?
- Thread starter Comp 670
- Start date
Rev like a crf50
Outlet is 1.5” and the elbow is 1.75”.
No notable difference from stock.
(Tried a bunch of cut sizes in between)
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sound of silence
when I was fooling with my WR450 snow bike, I tried 5 different pipe combinations looking for power and quiet comfort. When I found a FMF Q series, that was a big relief for me and my riding partners, knocking the sound down. Seemed as quiet as stock with a little hp improvement. My Ktm 500 xcw is stock. I have ridden with scores of KTM snow bikes with lots of aftermarket pipes, a loud fest in almost all cases. Loud is bad for the sport.......oh and your body if you care.
when I was fooling with my WR450 snow bike, I tried 5 different pipe combinations looking for power and quiet comfort. When I found a FMF Q series, that was a big relief for me and my riding partners, knocking the sound down. Seemed as quiet as stock with a little hp improvement. My Ktm 500 xcw is stock. I have ridden with scores of KTM snow bikes with lots of aftermarket pipes, a loud fest in almost all cases. Loud is bad for the sport.......oh and your body if you care.
I don't have a KTM but on my xr650r the FMF Q is nice and quiet, runs good. On my snowbike I run a CR500 with a Q on it. The 500 is an interesting beast. It sounds the absolute loudest when you start it and its idling in the parking lot, but it gets quiet when you start riding and even when you are wide open it doesn't reverb like a 4 stroke. Those 4 strokes with the wrong exhaust are really loud. While it doesn't really bother me personally it does bother other people who are out enjoying the forest for different reasons and for that reason loud pipes do bother me and think we should be responsible motorized enthusiast and do everything we can to not effect others out in nature including the wildlife. I feel it is irresponsible to run a really loud bike and people who don't do everything possible to keep their bike quiet are the reason we keep losing riding areas.
I putt around on a Harley as well, my bike is about 10 rides to town away from spinning 100,000 miles. I ride it all the time at all hours of the day and night. My neighbors still wave at me and talk to me because with this bike as well I am a responsible quiet exhaust owner. I don't think loud pipes save lives, unless the thinking is loud pipes close so many areas that eventually we will have no place to ride so we will be forced to stay home and play snowbike virtual reality games and we therefore wont be able to get hurt.
The turn down tip I would be curios to see what that does at distance. I think the issue for all of us is how far the noise carries. Like I said my 500 sounds kind of obnoxious in the parking lot but the noise doesn't carry over ridges or tons of distance, for whatever reason the noise is fairly localized. The 4 strokes the noise seems to carry for miles. I wonder if with the turn down tip the noise is just as obnoxious to the rider but for the people out on snowshoes or skis the noise wouldn't carry the same to them...and that is who we need to worry about.
The argument of hearing the guy coming the other way is silly...on my bike I have never heard another bike coming the other way, I think having a headlight of some sort makes a bigger difference singletracking through the forest than a super loud bike ever would.
I putt around on a Harley as well, my bike is about 10 rides to town away from spinning 100,000 miles. I ride it all the time at all hours of the day and night. My neighbors still wave at me and talk to me because with this bike as well I am a responsible quiet exhaust owner. I don't think loud pipes save lives, unless the thinking is loud pipes close so many areas that eventually we will have no place to ride so we will be forced to stay home and play snowbike virtual reality games and we therefore wont be able to get hurt.
The turn down tip I would be curios to see what that does at distance. I think the issue for all of us is how far the noise carries. Like I said my 500 sounds kind of obnoxious in the parking lot but the noise doesn't carry over ridges or tons of distance, for whatever reason the noise is fairly localized. The 4 strokes the noise seems to carry for miles. I wonder if with the turn down tip the noise is just as obnoxious to the rider but for the people out on snowshoes or skis the noise wouldn't carry the same to them...and that is who we need to worry about.
The argument of hearing the guy coming the other way is silly...on my bike I have never heard another bike coming the other way, I think having a headlight of some sort makes a bigger difference singletracking through the forest than a super loud bike ever would.
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We got to have a couple of days with a bike kit so it was just one skis and it was a blast . I wear ear plugs because my ride has a jaws pipe and is louder than I care for .
That being said , the 4 stroke bike with a stock exhaust is another story . My riding partner and I have voice activated comm sets and when the bike was any where near her it would drown out her machine that I normally could hear when she talked to me . She is also running a Jaws on that little 503 fanner but it's much quieter than mine .
I was very surprised because it was so noticeable and that has never happened with any sleds that I can think of that we have ridden with and some of those aftermarket cans on the sleds are stupid loud .
The following week we were riding with sleds and at a stop I heard that distinct sound , I couldn't see him but I knew where he was at in a higher elevation thick with trees . As the crow flies he was a good mile away . He was also riding with a sled that has a complete aftermarket exhaust but you could not hear a peep from it .
He does run a pipe on it in the summer but opts the stock for winter riding . Idling or even mid throttle no one would of guessed how much volume comes out of those 4 strokes but once he cracks it the stock bark alone stifles a moderately modded machine .
Someone will have to come out with a pipe that's routed differently because that will be a hard sell for a machine that's new to the winter sport even with the sledding community backing them .
That being said , the 4 stroke bike with a stock exhaust is another story . My riding partner and I have voice activated comm sets and when the bike was any where near her it would drown out her machine that I normally could hear when she talked to me . She is also running a Jaws on that little 503 fanner but it's much quieter than mine .
I was very surprised because it was so noticeable and that has never happened with any sleds that I can think of that we have ridden with and some of those aftermarket cans on the sleds are stupid loud .
The following week we were riding with sleds and at a stop I heard that distinct sound , I couldn't see him but I knew where he was at in a higher elevation thick with trees . As the crow flies he was a good mile away . He was also riding with a sled that has a complete aftermarket exhaust but you could not hear a peep from it .
He does run a pipe on it in the summer but opts the stock for winter riding . Idling or even mid throttle no one would of guessed how much volume comes out of those 4 strokes but once he cracks it the stock bark alone stifles a moderately modded machine .
Someone will have to come out with a pipe that's routed differently because that will be a hard sell for a machine that's new to the winter sport even with the sledding community backing them .
Repack often.
Repack often.
I got my bike new last 02/22/2017 and have about 108 hours and 1,9xx miles and while I don't really want to drill the rivets out of my endcap and get the pre-made OEM packing to replace it, I'm curious as to what it looks like. Maybe sometime this winter I'll get it done as I do have a pop rivet gun.
Both our KTM 300s came with pretty quiet stock mufflers however racing enduros in Canada and US requires spark arrestors. They clog up often with soot, which lowers (kills) performance - it probably will be worse in winter and no spark arrestor is needed in winter anyway.
I'm going to dedicate our after market spark arrestors (Enduro Engineering and FMF Q) to summer use and repack the stock units just for snow bike use. Then they are ready in advance for a quick bolt-on conversion every winter and the repacked spark arrestor for back to summer. The stock mufflers are quiet and the rivets are easy to drill and tap out the first time and replace with M6 button head screws, making subsequent packing easier.
I'm going to dedicate our after market spark arrestors (Enduro Engineering and FMF Q) to summer use and repack the stock units just for snow bike use. Then they are ready in advance for a quick bolt-on conversion every winter and the repacked spark arrestor for back to summer. The stock mufflers are quiet and the rivets are easy to drill and tap out the first time and replace with M6 button head screws, making subsequent packing easier.
noise police
as the snow bike sport progresses the noise issue is going to come around a bite us all in the azz. a lot of the snow bikes out in the woods are only approved for close course competition. A lot of those closed course MX bikes are flat obnoxious out in the woods.
the four stroke sound just flat carries, so 4 strokes need even more work to be quieted down.
As mentioned in an earlier post , 4 stroke sound carries, not so with 2 strokes.
I have sat on the NOrth ridge in the West Fork of Gold creek watching a dozen sleds and on a popular play hill. Only sound a mile away is one bike.........once and awhile a faint whisper of the 800s with aftermarket cans.
Last weekend two 300ktm 2 strokes in our group. Its like riding with electric bikes, hardly a sound when they ride behind you.
Just gota figure out how to squeeze two 300 motors into a bike frame.
as the snow bike sport progresses the noise issue is going to come around a bite us all in the azz. a lot of the snow bikes out in the woods are only approved for close course competition. A lot of those closed course MX bikes are flat obnoxious out in the woods.
the four stroke sound just flat carries, so 4 strokes need even more work to be quieted down.
As mentioned in an earlier post , 4 stroke sound carries, not so with 2 strokes.
I have sat on the NOrth ridge in the West Fork of Gold creek watching a dozen sleds and on a popular play hill. Only sound a mile away is one bike.........once and awhile a faint whisper of the 800s with aftermarket cans.
Last weekend two 300ktm 2 strokes in our group. Its like riding with electric bikes, hardly a sound when they ride behind you.
Just gota figure out how to squeeze two 300 motors into a bike frame.
Dirt bike magazines run sound test articles periodically. Most of these can be found with a quick online search.
Keep in mind that every OHV requires and exhaust with spark arrestor stamped with a USFS approval. Also, USFS noise regulations for OHV in Washington are set at 99 dBa. This level is measured with the "20 inch test" as described in SAE J1287.
Keep in mind that every OHV requires and exhaust with spark arrestor stamped with a USFS approval. Also, USFS noise regulations for OHV in Washington are set at 99 dBa. This level is measured with the "20 inch test" as described in SAE J1287.
So when the 99 dBa was enacted ? was it not more so for the two strokes ?? The two strokes are not the ones making the noise .
It is not a solution , the spark arrestor is being used as a crutch . It does not solve the problem .
The 99 dBa was put in place for all OHV, not just 2 stroke or 4 stroke. And the spark arrestor is required on all USFS ground.
I personally use the FMF Q, but I ride a 2 stroke.
The issue with the flow through glass pack mufflers is that they work best only on the higher frequencies, which is great for 2 strokes, not so much for the lower tones of the 4 strokes. So in this stage of the game, a turn down or deflector on the end of the pipe is likely the best option.
Several years ago, there was a product called the DB Snorkel. It was specifically aimed at 2 strokes at the time. It was a rubber extension that connected to the end of the exhaust with some extra turns to quiet things. It also had a "valve" of sorts, to accommodate higher rpm. Not sure if the concept would work on a thumper can, but a guy would have to fab his own, as the manufacturer stopped making them.
We certainly need something better, or we will start losing areas because of noise.
I personally use the FMF Q, but I ride a 2 stroke.
The issue with the flow through glass pack mufflers is that they work best only on the higher frequencies, which is great for 2 strokes, not so much for the lower tones of the 4 strokes. So in this stage of the game, a turn down or deflector on the end of the pipe is likely the best option.
Several years ago, there was a product called the DB Snorkel. It was specifically aimed at 2 strokes at the time. It was a rubber extension that connected to the end of the exhaust with some extra turns to quiet things. It also had a "valve" of sorts, to accommodate higher rpm. Not sure if the concept would work on a thumper can, but a guy would have to fab his own, as the manufacturer stopped making them.
We certainly need something better, or we will start losing areas because of noise.
When I was a kid I had an obscenely loud RM80. I thought it sounded cool, but my neighbors hated it. I found a 20 ft. piece of rubber hose that fit tight in the silencer.I could ride around with this crazy hose dragging behind my bike in relative silence. Of course the hose killed the power, but it allowed me to ride up the lane past their houses, then when I got in the trails I pulled it out and away I went. So this is my recommendation for loud 4 strokes. 2 strokes are not the problem and will be exempt from this foolishness. You're welcome.
OMG...no snow bike I know of rides past lane ways on the way to a trail.
... The trail is where we want to avoid pissing off non-snow bikers with load noise. Just make your bikes a little quieter and put up with the barley noticeable loss in power or continue to put up with bad press that eventually leads to our sport (both in summer and winter) becoming extinct on public lands.
... The trail is where we want to avoid pissing off non-snow bikers with load noise. Just make your bikes a little quieter and put up with the barley noticeable loss in power or continue to put up with bad press that eventually leads to our sport (both in summer and winter) becoming extinct on public lands.I disagree. I have tested back to back on a mx track on ktm 250f and 350f. I compared the xcw muffler sx muffler and sx with a turn down was always the quietest and made as much power as stock sx muffler. The xcw muf is choked for sure. My testing focus was peak and over rev which is all that matters on a snow bike (and small bore mx). Results might vary on a 450 of coarse but keep in mind that off idle snap is worthless on a snow bike and be careful not to judge the sound as the power. It's a common mistake loud pipes just sound faster but are often not much different where it really matters.
Haha
That’s great that you disagree with my experience. Lol
You tested different bikes at different temperature and altitude.
By response I’m referring to the ability to rev a gear out and pull the next gear in deep snow.
There’s simply no way to test (on a mx track) the constant heavy loads and extremely quick drop in track speed that shifting causes on snow.
I think I’m going to stick with what works for me............
Thanks for your input on what you found in your own testing..........
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Yea, Uncorked mx silencer is the best for power. For sure! But, loud as $hit, and I hate wearing earplugs when i ride. Would be nice to have a quiet option. Hard to believe that a turn down would kill power that much, but these exhausts, and the whole bike really, are a finely tuned machine. I think tunnel dump is probably the best answer. Someone that knows how to build a tuned exhaust needs to take a stab at using the snow to dampen sound.
I tested in the snow but sadly not on the same day and same conditions. That's why i use the mx track for tuning. Any way it was a ktm 350 snowbike and i got a used sx muffler for 50 bucks and welded a cheap piece of muffler pipe on it. Results will vary but I feel It would be a cheap experiment to at least give a try if you want quiet power.
Idaho regulations state that the exhaust must not exceed 96dB, with sound measured twenty (20) inches and forty-five (45) degrees from the exhaust outlet.
The rule pertaining to this can be found at "https://legislature.idaho.gov/statutesrules/idstat/title67/t67ch71/sect67-7125/".
With all of the groups and pending lawsuits that want to eliminate all motorized use in the forest let's not shoot ourselves in the foot by making a bunch of noise for a couple of horsepower. I'm afraid it is going to be past our lifetime before they have an electric motorcycle that can spin the track like a 450 or 500 4-stroke.
Let's protect the sport so we can all ride and enjoy our winter back-country.
The rule pertaining to this can be found at "https://legislature.idaho.gov/statutesrules/idstat/title67/t67ch71/sect67-7125/".
With all of the groups and pending lawsuits that want to eliminate all motorized use in the forest let's not shoot ourselves in the foot by making a bunch of noise for a couple of horsepower. I'm afraid it is going to be past our lifetime before they have an electric motorcycle that can spin the track like a 450 or 500 4-stroke.
Let's protect the sport so we can all ride and enjoy our winter back-country.
I agree with most of what has been said here. This season I went back to the dark side and set up a YZ to accompany my CR500. Riding side by side the CR500 is WAY quieter. My buddy set up the same bike, a YZ. We are both running the stock 10-11 YZ silencer which is the shorter and larger inside diameter version as compared to 12 and on. In 2012 Yamaha changed the silencer to meet sound regs and made it 2" longer and a few mm smaller inside diameter which choked off the bike and opened the doors for the after market to make loud free flowing race exhausts. My bike is an 11 so its what it came with. All that said the stock silencers are much quieter than my buddies FMF pipe that is on his WR which is obnoxiously loud. Its brutal even after a fresh repack.
I'd be all over making my bike quieter if there was a good option for it that didn't kill it. There's no doubt this sport and its participants, meaning me and everyone else, need to get out in front of this noise issue because its an easy out for shutting things down.
M5
I'd be all over making my bike quieter if there was a good option for it that didn't kill it. There's no doubt this sport and its participants, meaning me and everyone else, need to get out in front of this noise issue because its an easy out for shutting things down.
M5
