gabbett1
Member
That seems really low for the full shift force. I found a chart that shows exactly what you've listed here. Says preload is 35 kg and total force is 101 kg. Interestingly, (although probably not what you should do) if you add 101 and 35 to get 136 kg and convert that to lbs, it comes to 299 lbs. Which would be about the same as what I was running.
gabbett1
Member
What does the spring rate mean and how does it play into the overall rating of the spring?
The spring rate is kind of strange. It depends on the wire dia. number of coils. overall length. The spring rate can be all over the place going up the scale on a spring chart.
The best tuning info is the lbs of force at given height. Heights are generally spec with spring cover installed 2.5" and 1.25" with polaris springs. At engagement and at full shift out in inches and lbs force.
The best tuning info is the lbs of force at given height. Heights are generally spec with spring cover installed 2.5" and 1.25" with polaris springs. At engagement and at full shift out in inches and lbs force.
gabbett1
Member
It's been a hot minute since I've post on here. I think I'm close, but can't seem to get the last bit of it figured out. RPM's are holding nicely now. There's no dropoff and it hits RPM target almost immediately. I'm not able to make any speed though. Pulls really hard till about 60mph and then slowly climbs to ~85+mph. It's still climbing, but slowly. My Skidoo 850 gets to 100 mph in about 2/3 of the distance. My friends stock SRX is faster than my 850 so I can't imaging there's that much difference between a stock SRX and my piped and modded SX.
I did change my secondary spring from a yellow (35-85 lbs of force) to a red (60-116). It helped for sure, but the increase was minimal. This red spring is the same one that was in the snowmobile when it was fully modded years ago so I can't imagine I need to go even heavier.. I'm just at such a loss.
I'm still running a 49 degree helix. As I said before, it was the same helix angle as my friends SRX. I suppose I could try different helix angles, but they are not easy to change.
I really don't think that bearcat secondary is doing you any favors. It is built for utility low speed work and the extra large diameter is throwing off the shift ratio all the way up. It is so large that your primary will likely not close up totally. It you could find an old eltigre secondary to try...I think you might have better luck.
gabbett1
Member
I guess it's possible, but I have read all over the internet of people doing this conversion (on other Arctic Cat's) and getting great results. The primary was paired with this secondary for this sled. I know it used to work. I used to race it with this setup. It would blow Thundercats out of the water. BUT, that was years ago and the sled has been messed with by others since then. I'm trying to reverse engineer what they did.
gabbett1
Member
UPDATE: So I've made some progress and in doing so, I feel pretty silly. I found out that I had the wrong belt all along. It was about a quarter inch too long and it wasn't allowing the secondary to fully open (I had to get shims to open the secondary a tad to fit the smaller belt). Once I made that change, I picked up about 5 mph in the run distance I have. Then I decided to try a different helix. I swapped out the 49 for a 51. Picked up another 5 mph. Still think it's about 5-10 mph slow for the run I do, but it's a big improvement!
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gabbett1
Member
Made another minor adjustment after doing a good ride yesterday. Loosened the secondary spring one notch and it was suddenly a completely different sled! It really wants to run now.
My favorite spring for the cat clutch is the blue secondary spring. Blue is a softer spring than the yellow.
gabbett1
Member
If I changed springs, wouldn't that potentially cause slippage? I'm not sure how much leeway there is when it comes to the secondary spring.
Not necessarily. If you pickup performance by less spring tension with the yellow spring?
Then I would try the blue spring... in one hole tighter setting.
I run my blue springs in centre hole or one hole tighter depending on application. Trail ride or drag race set up.
Then I would try the blue spring... in one hole tighter setting.
I run my blue springs in centre hole or one hole tighter depending on application. Trail ride or drag race set up.
gabbett1
Member
Hmm, okay. I do have the ability to move the yellow spring one more hole. I guess I need to look up the spring rates of the yellow and blue springs.
Yellow part number 0148-227. Rated at 92 lbs.
Blue part number 0648-012. Rated at 79 lbs.
White part number 0648-010. Rated at 58 lbs.
Red/Black part number 0648-702. Rated at 42 lbs.
Blue part number 0648-012. Rated at 79 lbs.
White part number 0648-010. Rated at 58 lbs.
Red/Black part number 0648-702. Rated at 42 lbs.
gabbett1
Member
If I'm not mistaken, each spring has a range of pressure, yes? If so, then the notches in the clutch is setting where in that range the spring is set? If that's the case, then having the yellow and blue spring each set at the same/similar force, how would each spring rate change as the clutch opens?
Yes. The four springs have the spring tabs in the same location so the degree of twist is going to be the same on all four spring.
What changes the spring rate is the wire Dia. And number of coils. If you twist the yellow in you hands and then twist the blue in your hands...you can feel a slight difference in the rate.
The Red/Black i would stay away from. It is more a long compression spring vs the short torsional yellow and blue.
I have never found the need to run anything softer than the blue. Good luck.
What changes the spring rate is the wire Dia. And number of coils. If you twist the yellow in you hands and then twist the blue in your hands...you can feel a slight difference in the rate.
The Red/Black i would stay away from. It is more a long compression spring vs the short torsional yellow and blue.
I have never found the need to run anything softer than the blue. Good luck.
gabbett1
Member
Sorry for all the questions. What would be the possible up side to running the blue vs the yellow? Possible down side? Is there a HP rating in which each spring is recommended? Or perhaps the better question would be, what HP are you running with the blue spring?
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Harder upshift more acceleration more top speed. Down side if it doesn't work for the application...poor backshift off/on throttle lazy feel and over shifting on top end and falling or search rpm.
General rule of thumb for this clutch is...if one or two hole less preload is better? Run a blue spring set on centre hole location.
General rule of thumb for this clutch is...if one or two hole less preload is better? Run a blue spring set on centre hole location.
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gabbett1
Member
Hmm, okay. One thing I did fail to mention earlier was that when I did my runs, I wasn't making peak RPM. I forgot to bring my primary tools and parts with me to make that adjustment. I was only getting about 8,600 and I want to tarket 9,000. So do you think I should stick with my spring setting for now and see how it performs?
If you feel the upshift and off/on throttle bach shifting is good for your application? I would leave it alone and search for a flatter finish angle on your helix.
I don't remember what you are running but an example is. If running a 55-53 and not holding peak rpm? Try a 55-51 or 55-49.
I don't remember what you are running but an example is. If running a 55-53 and not holding peak rpm? Try a 55-51 or 55-49.
gabbett1
Member
I'm running a straight 51 helix. I was running a 49 before but changed it when I wasn't getting the acceleration I wanted. That was before the spring change though.