Ahhh OK. There is your problem you need a dual angle.
gabbett1
Member
Really? Why is that? I do know that the old setup (when it was an 800) was a straight helix. I guess I just don't know much about the helix and how to determine when you need a dual angle.
Also, just for clarity, when I said I wasn't reaching peak RPM it wasn't that there was bog or anything. The engine sounded great and it hit the RPM and held it. I just thought my weights were off. I haven't adjusted the primary since I discovered I had the wrong belt.
Straight angles are great for big high torque twin cylinders with a super wide flat power curve to clutch.
A piped high rpm triple has a narrow hard to clutch power band. So to keep it on the pipe at 9000 rpm you have to slow the upshift down (not so aggressive up top). The dual angle does just that. 51-49 will give you same characteristics down low but help hold the 9000 rpm up on top end.
A piped high rpm triple has a narrow hard to clutch power band. So to keep it on the pipe at 9000 rpm you have to slow the upshift down (not so aggressive up top). The dual angle does just that. 51-49 will give you same characteristics down low but help hold the 9000 rpm up on top end.
gabbett1
Member
Welcome to another year of sledding. So we have some early snow this year and I've been out doing some testing. I didn't change anything from last winter and wanted to get a baseline. I have a nice field I test in. We have about 4-6 inches of snow. I noticed that the sled will pull strong all the way up to about 80 and then stops accelerating. I decided to switch the yellow secondary spring to the blue one that you suggested last time. Went to test again, and same result. Climbs to 80 and stops going any faster. We have some nice snow/ice covered roads so I decided to take a couple passes on it. Roars up to 90 and is still climbing hard. So, for some reason my setup doesn't like any kind of snow at all. Seems to me that it still has to be something minor in the clutching but I'm not sure what it could be. Possibly if the helix is to aggressive? What are your thoughts?
If the helix is to aggressive...it will search for rpm on acceleration or pull the engine down to low and not accelerate properly.
To aggressive helix will have a lazy backshift as well when off/ on throttle.
Maybe you are running out of gear ratio? To low
To aggressive helix will have a lazy backshift as well when off/ on throttle.
Maybe you are running out of gear ratio? To low
gabbett1
Member
I don't think it's gear ratio. It's stock gears and stock you can get to 105mph. 78 mph is a far cry from 105. Plus remember that I'm hitting 90 and still accelerating hard on hard pack roads.
gabbett1
Member
Changed my 51 degree helix to a 52/48 (that's the only multi angle one I have). Picked up a few mph (in the field) and it seemed like it wanted to go a little more, but I ran out of room. Also noticed that the snow is pretty heavy/wet right now so that is probably holding me back as well. I would think this should have more than enough power to overcome, but maybe not.
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gabbett1
Member
Question. Does it hurt to have the engage RPM too low? Typically I hear of people setting them up for a 4000 to 4500 engage RPM. Mine is around 3200 ish. That doesn't effect other area's of the performance does it?
Not at all in my opinion. Myself being a deep snow rider, the lower engagement reduces trenching and gives the sled the ability to climb up on top of the snow. I intentionally set my sleds up to engage under 4k
Snowdad4 is right. Lower engagement won't change shift speed or peak rpm.
It's just a tuning tool to suit rider and riding conditions.
Drag racing with good hook up you want higher engagement. Deep snow mountain riding...the lower the engagement the better.
It's just a tuning tool to suit rider and riding conditions.
Drag racing with good hook up you want higher engagement. Deep snow mountain riding...the lower the engagement the better.
gabbett1
Member
Well I'm still not 100% where I need to be with my clutching. I thought I was close. I just haven't been able to hit peak RPM and now I'm finding that I'm lowing weight on my cam arms and not gaining peak RPM. So I went back to the drawing board. Looked up what is recommended for my sled (if stock) with this clutch. Man, it's very different than what I'm running. Stock, it wants to use a silver/black spring and 52.3 gram weights. I'm running a blue spring currently with 46.2 weights and I'm still 400-500 RPM off of peak RPM. So this is telling me that a stock sled uses a heavier spring and much heavier weights? Where did I go wrong? I'm seriously questioning everything at this point.
I highly doubt I'd use the same spring and weights as stock, but I also wouldn't think I'd be going down in weight on each to achieve peak performance.
I highly doubt I'd use the same spring and weights as stock, but I also wouldn't think I'd be going down in weight on each to achieve peak performance.
I still think that large Bearcat secondary isn't doing you performance and good. It's a low ratio secondary made for low speed high load work.
Getting away from clutching. There could be other issues going on. Exhaust flanges worn out and pipes not building proper pressure? Silencer burnt out and nor utilizing the stinger size correctly? Hard to say what direction to go...with out seeing and going through the sled. Just my thoughts.
Getting away from clutching. There could be other issues going on. Exhaust flanges worn out and pipes not building proper pressure? Silencer burnt out and nor utilizing the stinger size correctly? Hard to say what direction to go...with out seeing and going through the sled. Just my thoughts.
gabbett1
Member
I don't think it's the secondary as much as it's the overall clutch tuning. When I originally made adjustments to the secondary spring and got the proper belt, I was hitting 103 mph and still climbing before running out of room on hard pack. That's without hitting peak RPM too. Just can't get it to hit peak rpm and it really won't get much speed in any kind of deeper/wet snow. It's the deeper snow where it will hit about 80 and stops climbing (all while holding RPM, just about 400-500 too low). Not sure if that's because my peak RPM isn't being met? Would 400-500 RPM be that large of a power drop?
Also, the question still remains. Why would a stock SX run a heavier spring and weight combo than a piped/higher horsepower one?
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With those pipes...being 400-500 rpm off peak will make a difference. They have a really narrow powerband and hard to keep on the pipe day to day.
The stocker with heavy weights is do to a lower and wider rpm band to clutch to. Kind of like a big twin that runs 8000 rpm. Sooo easy to clutch.
The stocker with heavy weights is do to a lower and wider rpm band to clutch to. Kind of like a big twin that runs 8000 rpm. Sooo easy to clutch.
gabbett1
Member
I was just reading an interesting thread where people were discussing two ways in which to tune a primary clutch (all else being equal). A heavy weight, heavy spring setup and a light weight, light spring setup. Sounds like you can do it either way effectively based on what you're looking for. I'm probably riding the lighter weight/spring version for my sled right now.
Calling Clutch Gurus... Primary Spring/wieght
I hate to admit it but I'm a bit confused about primary clutch spring pressure and the weights. What is the difference between these two scenarios... given the same design to the weights 9not heelclickers or other wieghts that you can change position on0 All other items are the same...
www.snowest.com
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