Secondary wrap?

[Doc Harley]

For pure acceleration & top speed what is the best way to test?
It is my impression that you want the minimum amount of wrap without belt slippage. Is that correct?
Dalton B/O V2 @ 80° using XS825 for reference.
Reading old posts can be confusing as you don't exactly know posters test methods. Week later, differing conditions, etc.?!?!

Ty....... Joe

 

[Doc Harley]

Also, how does this belt look? 350 miles with lots of testing. Looks glazed to me?!?! Idk...

 

[jonlafon1]

Lots of variables on the secondary SPRING used and twist. Helix angle, track height, studs, HP/tune. Biggest ones imo are helix angle, HP, traction/track hight/studs. Best way to get it right is spend the time testing for clutch temps and clutch faces/ belt slipping marks. No one is going to give the magic spring and twist that’s works on every sled as to many variables from one sled to another. Most don’t want to put the time in and get it perfect.

 

[Doc Harley]

Lots of variables on the secondary SPRING used and twist. Helix angle, track height, studs, HP/tune. Biggest ones imo are helix angle, HP, traction/track hight/studs. Best way to get it right is spend the time testing for clutch temps and clutch faces/ belt slipping marks. No one is going to give the magic spring and twist that’s works on every sled as to many variables from one sled to another. Most don’t want to put the time in and get it perfect.

Right on. Well...I'm up to 192 studs. So I'm hopeful of taking that out of the equation with the ability to move forward, yet this year.
Thoughts on the pic of belt?

Thanks Jon.

 

[Simplespeed]

For pure acceleration & top speed what is the best way to test?
It is my impression that you want the minimum amount of wrap without belt slippage. Is that correct?
Dalton B/O V2 @ 80° using XS825 for reference.
Reading old posts can be confusing as you don't exactly know posters test methods. Week later, differing conditions, etc.?!?!

Ty....... Joe

Best way to test is to first have a consistent reliable method of measurement. Timing lights, radar gun, dragy, data logging, gps or another sled .. Your goal is to get to your optimal power band at all throttle positions.. In other words if your power is made at lets say 9000 rpms then from a standing start and you stab the throttle to the handle bars your clutching should shift at 9000 or in simple terms your tach should go right to 9000 and stick there… Now your Primary clutch spring and weights control when and how fast the front clutch will shift and at what RPM it will finish, along with how high the belt will climb up the face… Some tunes and or motors like to be loaded ( a little slower shift ) and some like to be free wheeled ( a little faster shift ) To answer your second question, Less side pressure, less wraps, and less helix angles usually will result in less friction and alot less back shift and can result in belt slip .. If you can get a balance between both clutches and your just racing straight line you can get this set up to work but you risk sucking the belt in too fast or taking off in second gear or in other words it can be inconsistent and changing conditions can effect performance. Jon is right as so many factors effect results and each sled is not the same..Start your testing using straight helix and changing one thing at a time, document that change, then try the next change… No one wants to give you their best set up if they spent time finding that real good clutch set up…

 

[Doc Harley]

Simplespeed, right on. I understand your reply. I probably didn't ask the question correctly. What I was looking for, is what to look for?
Sec. Spring. Just as a starting point. Do I lessen the wrap until I get slippage? Or do you crank it up as tight as you can? Just the basic principles, not looking for part#'s.
Then once that's established, move on to the next thing.
These are those basic questions that I need to understand, even if I had a draggy or like.
Most guys say get traction done first. This will take the guesswork out of the clutching. So that's kinda what I've done.
So, if I have good traction, how do identify clutch wrap, as perfect? I assumed rubber smeared all over the Sheaves And or 200 °Secondary temps, would tell me something is not right.

 

[Simplespeed]

Yes traction first but that can be adjusted for conditions.. you can find your ideal clutch settings when you arrive at the following… The shift is strong (motor pulling hard ) the shift is fast hence needle goes right to desire top rpm, clutch shift creates no more than luke warm temps, and your belt travels to 1 to 1 where its most effective and efficient. You will know your on the right track as the sled starts to give that arm ripping pull your after… How do you get there ? Balance through your entire system…Do not over look the balance of both clutches.. Its spinning at such a high rate that just a couple of grams in wrong spot can have great effects… Spinning balance matters and your springs work together… Almost right is still wrong if your after a good set up,,, Once you ride a perfectly clutched snowmobile you will never forget it and there is difference…

 

[Doc Harley]

Yes traction first but that can be adjusted for conditions.. you can find your ideal clutch settings when you arrive at the following… The shift is strong (motor pulling hard ) the shift is fast hence needle goes right to desire top rpm, clutch shift creates no more than luke warm temps, and your belt travels to 1 to 1 where its most effective and efficient. You will know your on the right track as the sled starts to give that arm ripping pull your after… How do you get there ? Balance through your entire system…Do not over look the balance of both clutches.. Its spinning at such a high rate that just a couple of grams in wrong spot can have great effects… Spinning balance matters and your springs work together… Almost right is still wrong if your after a good set up,,, Once you ride a perfectly clutched snowmobile you will never forget it and there is difference…

Awesome.....that you for responding.

 

[Simplespeed]

Hey no problem, your tuning big power, might take a little testing and some parts but its well worth the time spent… And it makes even more special when you get it done yourself…

 

[Doc Harley]

Hey no problem, your tuning big power, might take a little testing and some parts but its well worth the time spent… And it makes even more special when you get it done yourself…

Well ....I'll never say I got there all by myself. Lol.
But understand & appreciate the work involved.
It's just my opinion, but I think many crank these things up and are completely satisfied. I'm not that guy.
Looking for an advantage over those guys. No disrespect meant....

 

[Simplespeed]

In other words you do not want to leave any stones unturned ??? Lol. I hear you.. if your really serious about getting your power to the ground, testing, testing, testing is your path to success.. your results will steer you.. The best in the business spend many hours testing… What are they testing? Clutching, Gearing, suspension, traction. As conditions change, so do their set ups..

 

[Doc Harley]

As conditions change, so do their set ups..

Well...I kinda like the set it and forget it approach or kiss (Keep it simple stupid)
Head hunting starts in the 5°f degree range and ends at 15° hard pack only....lol

Ill spend the other days just waiting.

 

[STAIN]

To test is to know. Don't be afraid to try something you don't think will work.
nothing comes easy. it all takes time, time. time. usually, the fastest guys are the ones who spent the most time testing.
Take notes!!!!!!!!

 

[jonlafon1]

To test is to know. Don't be afraid to try something you don't think will work.
nothing comes easy. it all takes time, time. time. usually, the fastest guys are the ones who spent the most time testing.
Take notes!!!!!!!!

Well said!

 

[Doc Harley]

To test is to know. Don't be afraid to try something you don't think will work.
nothing comes easy. it all takes time, time. time. usually, the fastest guys are the ones who spent the most time testing.
Take notes!!!!!!!!

Yes, I'm like you in a sense that I'd like to make the best educated decision the first time. Then spend the time making it work.
On another note, I'm really liking the MS16sm tune for all it's glory. Pretty much does everything except throw the deto lights on.
I'll work around that for now.