AM Secondary Springs and where to order
- Thread starter Dock
- Start date
For what secondary?
EPI has springs.
EPI, Dalton...several others....curious why you have the need to go stiffer though?? Stock purple is almost too stiff, you must be working with a huge amount of primary weight or a very steep helix?? 
http://www.goodwinperformance.com/skidooclutches.asp
dk/blu/wht = 220/335
dk/blu/red 250/345
dk/blu/yel 235/335
What you'll find as you increase spring forces, this will cause the steady throttle rpms to be raised up.
Regarding Spring force determines rpms at steady throttle;
If you are cruising along from hill to hill at about 6200 with a purple 225/300 secondary spring
Then to change to a 235 start force, you'll see about 6400~6500 rpm
Then to change to the 250 start force, you'll see about 6700 rpms
...Bring note pad along and take notes on differences in "rpms" you see under full throttle.
dk/blu/wht = 220/335
dk/blu/red 250/345
dk/blu/yel 235/335
What you'll find as you increase spring forces, this will cause the steady throttle rpms to be raised up.
Regarding Spring force determines rpms at steady throttle;
If you are cruising along from hill to hill at about 6200 with a purple 225/300 secondary spring
Then to change to a 235 start force, you'll see about 6400~6500 rpm
Then to change to the 250 start force, you'll see about 6700 rpms
...Bring note pad along and take notes on differences in "rpms" you see under full throttle.
D
Dock
Member
i really started getting into clutching last year, it is something that i really want to learn but have found it is a slow process. right now like i said i have a yellow Sec spring and i'm running stock TRA with "No" wieght it in on about clicker 3 which gives me 8200-8300 RPM. Seemed to me last year that the lower Clicker angle cooled the clutches down casuse I get way to much belt heat, plus i think the TRA doesn't fully shift out on higher clickers. I went back and forth with my Shockwave helix from low to high angles, i found that the RPMs don't hold nearly as good with the higher angle, don't know if that is what they are supposed to be like but that is what i found. Plus 19-49 gears.
My goal for this year is to save belts, F*ck i go though a belt a ride right now, i'm pulling the motor and modifying my motor mounts so that i can align the clutches perfect, no offset (like my buddies 2006) plus i'm gonna toss on a new track. I get good track speeds i just need to solve this belt blowing problem.
Anyway i'm rambling, thanks for the charts....
My goal for this year is to save belts, F*ck i go though a belt a ride right now, i'm pulling the motor and modifying my motor mounts so that i can align the clutches perfect, no offset (like my buddies 2006) plus i'm gonna toss on a new track. I get good track speeds i just need to solve this belt blowing problem.
Anyway i'm rambling, thanks for the charts....
Stiff secondary spring and light pin weight = not loading the engine and blown belts. Throw some pin weight in there and shallow up the Shockwave for the hills.....you'll have more belt squeeze on both ends and more consistant RPM under a load. I think you'll find everything is a compromise with the Shockwave...it works "good" but doesn't have the angle spread to work as good as possible in the hills. We need a good clutching thread to make the summer go faster 
OT will answer all of your questions
D
Dock
Member
Stiff secondary spring and light pin weight = not loading the engine and blown belts. Throw some pin weight in there and shallow up the Shockwave for the hills.....you'll have more belt squeeze on both ends and more consistant RPM under a load. I think you'll find everything is a compromise with the Shockwave...it works "good" but doesn't have the angle spread to work as good as possible in the hills. We need a good clutching thread to make the summer go faster
Is it not that your RPMs would determine your Clutch squeeze, ie to much clutch squeeze lower RPMs and visa versa... so... what is the better setup to run, high helix angle and a higher clicker OR lower helix angle and lower clicker... the lower helix and lower clicker would be tighter belt squeeze all round would it not...??? SO......
one step further what is the down side to "lots" of belt squeeze? i guess the down side to not enough belt squeeze would be the primary slipping over the belt creating heat.
Clutches will run cooler when you can prevent rpm fluctuation or reduce it to least amplitude as possible.
Lowest temperatures will be revealed no matter if the temps are cool or incinerating, no matter what temperature you record, the lowest you will see (regardless of what the temps are), [can you see I am trying to drive this point home] the lowest temps will be seen when you run the engine at rated rpms under full throttle.
(Under shifting)
The moment you start to over rev is the moment the clutches stop upshifting (stalled upshift) so to get the clutch to shift then must find "rated rpms" under full throttle. With over rev If you were to get higher mph on a flat surface, then the reason you get the xtra mph is by virtue of the increased rpms.
(Over shifting)
The moment you under rev, same thing, the clutches cease to upshift (stalled upshift)
Or
the clutches will start to open however the rpms will reduce and mph will cease to increase.
In the end the lowest temps will be seen when you can run the engine at rated rpms under full throttle. The challenge is to get the engine to recover to rated rpms when cycling the throttle in loaded conditions.
Lowest temperatures will be revealed no matter if the temps are cool or incinerating, no matter what temperature you record, the lowest you will see (regardless of what the temps are), [can you see I am trying to drive this point home] the lowest temps will be seen when you run the engine at rated rpms under full throttle.
(Under shifting)
The moment you start to over rev is the moment the clutches stop upshifting (stalled upshift) so to get the clutch to shift then must find "rated rpms" under full throttle. With over rev If you were to get higher mph on a flat surface, then the reason you get the xtra mph is by virtue of the increased rpms.
(Over shifting)
The moment you under rev, same thing, the clutches cease to upshift (stalled upshift)
Or
the clutches will start to open however the rpms will reduce and mph will cease to increase.
In the end the lowest temps will be seen when you can run the engine at rated rpms under full throttle. The challenge is to get the engine to recover to rated rpms when cycling the throttle in loaded conditions.
The key is finding a "balance" between the primary and secondary....anytime one is overpowering the other there will be excessive slip/heat and inefficiency. As in the first post using little pin weight and a stiff secondary spring, this is creating an imbalance between the 2 clutches.....less pin weight will always require either less secondary spring, less primary spring or more helix...or a combination of these to achieve that "balance".
D
Dock
Member
so much information… 2 things,
1) So what happens in you increase the primary and secondary force equally, more force all round? Less Slipping? what is the downside to having to much force?
2) DJ do you mean when the clutched stop up shifting they will not close anymore physically because they have reached there limit or because the engine has no more power to close them further? What I do and my theory is (again very new at this) I gear to as fast as I need to go, my sled tops out at about 90MPH on trail (because I will never attain 90MPH hill climb/powder) and I don't need to go 120MPH so why not transfer that high speed to torque. From there I have worked on the clutches to get as much weight in the primary running on the lowest clicker, with the lowest angle on the shockwave and a stiff sec spring. Again I like the lower clicker angles because it seems to give me more up shift at the higher trackspeeds.
I guess my goal of this whole thing is to get the stiffest Sec spring available, run the lowest angle helix I can and weight the primary to suit. I'm hoping to get a little belt heat as possible (eliminate the clutches slipping over the belt) from this set up and try to save belts.
1) So what happens in you increase the primary and secondary force equally, more force all round? Less Slipping? what is the downside to having to much force?
2) DJ do you mean when the clutched stop up shifting they will not close anymore physically because they have reached there limit or because the engine has no more power to close them further? What I do and my theory is (again very new at this) I gear to as fast as I need to go, my sled tops out at about 90MPH on trail (because I will never attain 90MPH hill climb/powder) and I don't need to go 120MPH so why not transfer that high speed to torque. From there I have worked on the clutches to get as much weight in the primary running on the lowest clicker, with the lowest angle on the shockwave and a stiff sec spring. Again I like the lower clicker angles because it seems to give me more up shift at the higher trackspeeds.
I guess my goal of this whole thing is to get the stiffest Sec spring available, run the lowest angle helix I can and weight the primary to suit. I'm hoping to get a little belt heat as possible (eliminate the clutches slipping over the belt) from this set up and try to save belts.
The helix has a much bigger impact on belt squeeze (except possibly at low speeds) then the secondary spring. Helix angles are a HUGE factor, especially in the hills.
More weight and less helix vs light weight and steeper helix....the heavy setup "tends" to be more RPM stable and hold track speed on a climb better than light weight....but light weight setups are a little more responsive at low speeds (generally).
We have had ZERO belt problems with our XP's with our setup....1000ish miles of mostly deep, heavy Wa snow and alot of those with a 174-2.5 track, not a single blown belt and great track speed, consistant RPM. It gets expensive trying to find the sweet spot. ....but playing with setup is the only way to learn.
More weight and less helix vs light weight and steeper helix....the heavy setup "tends" to be more RPM stable and hold track speed on a climb better than light weight....but light weight setups are a little more responsive at low speeds (generally).
We have had ZERO belt problems with our XP's with our setup....1000ish miles of mostly deep, heavy Wa snow and alot of those with a 174-2.5 track, not a single blown belt and great track speed, consistant RPM. It gets expensive trying to find the sweet spot.
....but playing with setup is the only way to learn.
DJ do you mean when the clutched stop up shifting they will not close anymore physically because they have reached there limit
--yes, the clutch can not "stroke" any more, it has stopped after the greatest amount of movement @ full shift over drive.
DJ do you mean when the clutched stop up shifting they will not close anymore physically?
--yes even prior to full "Stroke", prior to full shift out.
An example would be when you are climbing a hill and hit say 45 mph track speed and cannot gain any more track speed. If you are geared for 90 mph at full shift overdrive, then where about would the belt be on the sheave face at the primary or secondary?....about 1/2 way to full stroke.
or because the engine has no more power to close them further?
--yes, the load that the secondary clutch sees "senses" (sled weight/driver/snowload/chassis speed/track speed...etc = combined load) the load that the secondary senses overcomes "the push from the primary" and the upshift will stall.
Again I like the lower clicker angles because it seems to give me more up shift at the higher trackspeeds.
--If you have had a fluctuating rpm problem with this kind of calibration values, THEN you can raise the clicker and increase the backshift capacity, ability for engine rpm recovery - to achieve the same top end you can then take your primary spring final force and lower it. So for example if you had a primary spring force with a xxx/350 finish on a higher clicker number and had a lack of top end; Then take the final force and lower it 20~30 lbs like going to a xxx/320 finish force. That lower force will help the clutch push harder on top end mph where you want to go fast, while using a higher clicker number.
--yes, the clutch can not "stroke" any more, it has stopped after the greatest amount of movement @ full shift over drive.
DJ do you mean when the clutched stop up shifting they will not close anymore physically?
--yes even prior to full "Stroke", prior to full shift out.
An example would be when you are climbing a hill and hit say 45 mph track speed and cannot gain any more track speed. If you are geared for 90 mph at full shift overdrive, then where about would the belt be on the sheave face at the primary or secondary?....about 1/2 way to full stroke.
or because the engine has no more power to close them further?
--yes, the load that the secondary clutch sees "senses" (sled weight/driver/snowload/chassis speed/track speed...etc = combined load) the load that the secondary senses overcomes "the push from the primary" and the upshift will stall.
Again I like the lower clicker angles because it seems to give me more up shift at the higher trackspeeds.
--If you have had a fluctuating rpm problem with this kind of calibration values, THEN you can raise the clicker and increase the backshift capacity, ability for engine rpm recovery - to achieve the same top end you can then take your primary spring final force and lower it. So for example if you had a primary spring force with a xxx/350 finish on a higher clicker number and had a lack of top end; Then take the final force and lower it 20~30 lbs like going to a xxx/320 finish force. That lower force will help the clutch push harder on top end mph where you want to go fast, while using a higher clicker number.
D
Dock
Member
So what about heat? What temp should the clutches run at? I just bought a Laser temp guage and i'm gonna test the clutches this winter, i know that my clutches get so hot that if i put a drop of water on them it is instant Vaporization.
I have my Sled apart right now and i'm going to change the air intake, basically i'm not going to use the air box at all, so i'm thinking of cutting out the insides of the air box to alow air to flow though and i hope this will help cool everything. Any input?
Thanks
I have my Sled apart right now and i'm going to change the air intake, basically i'm not going to use the air box at all, so i'm thinking of cutting out the insides of the air box to alow air to flow though and i hope this will help cool everything. Any input?
Thanks
Not uncommon for severe duty (mountain throttle positions/time) to be in excess of 160 degrees.
You input the power of an 800 vs. a load you put the sled against and the clutch temperature will raise. Keep adding time and more time will cause the clutches to reveal more heat.
Clutch fitness also will have an influence on heat, especially the fact of sheaves being in parallel. Better the sheaves maintain parallel (Good bushing fitness) then the temps have the capacity to be less.
You input the power of an 800 vs. a load you put the sled against and the clutch temperature will raise. Keep adding time and more time will cause the clutches to reveal more heat.
Clutch fitness also will have an influence on heat, especially the fact of sheaves being in parallel. Better the sheaves maintain parallel (Good bushing fitness) then the temps have the capacity to be less.
