Better backshift - What secondary spring would you suggest?

[Frostbite]

I have a 09 M8 153" Sno Pro. I have a SLP single pipe installed on the sled.

In the secondary I have the stock orange secondary spring installed with a shift assist washer and a Black Diamond 42/36 helix.

The primary is now a SLP Black/pink 120/340 with 73 gram Arctic Cat weights (for now). I ride from 4-7,000 feet and weight 170.

The backshift isn't bad but, it isn't stellar either. Is there a slightly stronger secondary spring anyone would recommend that may help a bit with the backshift?

I don't understand how to read the secondary spring specifications either. I am used to Yamaha secondary numbers. Do the Arctic Cat secondary spring numbers read like the primary springs since they aren't used in a torsional application?

Thanks for any help you can provide

Any help on the subject would be appreciated. A spring chart with numbers for comparison would be even better.

Thanks

 

[furthur]

You're gonna get a lot of different answers to this. Part of the problem is running those lighter weights, which you need for the pipe, with an aggressive helix. The other problem is, you can run a stiffer secondary spring, but most will only have more backshift at higher shift out, not lower, which is where you need the backshift, especially with that progressive helix. I haven't found a listed spring anywhere that will be stronger at beginning shift, and the same or lower force at the end, except for Team springs, which I'm not running right now. If you want more backshift down low, you're gonna need something that starts at about 190-200 lbs at 2.9". If you don't wanna hurt total shift out, you need to keep final force near 280 lbs at 1.6". This gives a very low spring rate of 62 lbs per inch (orange is 81 lbs per inch)...this is gonna be a long spring, small dia. wire. If you find one that's not a team spring, let me know...

John

 

[WyoBoy1000]

I wouldn't run anything stiffer in the sec. You should look into diff primary weights. A good starting point is to run exactly what slp recommends and go from there. I finally ran there exact recommendations and it may not be the best but it is better than anything else I tried this year and have 400 miles on my belt and still going( thats rare for me)

 

[blackcloud2k]

Here is a post I keep saved. Has almost all of the companies spring specifications and part numbers.

http://www.snowest.com/forum/showthread.php?t=45277

 

[WyoBoy1000]

Thanks for the thread.

 

[summ8rmk]

I went to a torsional secondary 38/36 sno-pro green. I'm not a clutch expert but i do know that my sled performs alot better all around.

 

[Frostbite]

What a great spring link!

I made SEVERAL copies for my records. I'm still not 100% on understanding the secondary spring rates. They appear to be the same as the primary springs and I guess they would be since, stock there isn't a torsional loading of the secondary spring.

The Goodwin springs look interesting.

The 140/360 Purple primary spring (my stock A/C Yellow/white 122/285)

and the

The 185/315 Blue/Orange secondary spring (my stock A/C orange is 175/280)

Helixes - on my M8 there was a 36 degree helix stock. I went to a 42/36 and I like it but, I read about guys liking the 44/40 and the 44/38 or a 44/36.

I understand the finish angle of the helix (the second number) is one of the two ways of loading the motor (the other is through the weights in the primary). In a nutshell, the higher this second number on the helix, the lower your shift speed (top RPM) will be while climbing. Also, the higher the finish angle of the helix the less stellar the backshift, right?

The first number on a progressive helix reflects how hard your motor is loaded (via the secondary) upon clutch engagement. How high is too high for an Arctic Cat mountain sled in the deep powder? I know higher is better for a drag race but, it comes with a potential cost of digging holes repeatedly in the fluff.

 

[WyoBoy1000]

My understanding is the higher the angle the faster the shift up and down. My sled bogs with a straight 36 because it wont shift fast enough. on the second angle it may be faster but not better if your sled can't hold the angle. If it can't pull the second angle it may shift slower or not as far. think of it like gears, lower number angle takes more twist to get to the same shift point as a higher angle. If you do any more riding this year your welcome to try my 44/36 just to see how it compares. Last weekend I was holding slow speeds down hills with this helix, slow enough it shifts all the way out and lets go in the primary.

 

[furthur]

My experience with my M7 matches Wyoboys's...steeper helixes backshift faster, but load the motor to much climbing, sometimes.

Frostbite, that BD helix is probably a progresive, no? I'll post the tracing I did of a couple of helixes, including a BD 46-36 progressive. Notice the progresive is still pretty steep, well after the 44-40 has transitioned. I found this helix too much for my stock M7 to pull while climbing (with the goodwin blue), but it was wicked fast on hardpack.

My experience, yours may vary.
John

 

[Frostbite]

Thanks for the picture but, I studied it but I don't quite get it?

I must have tested 50 helixes for Dalton when the RX-1 Mountain came out. I settled on a 54/42 as one heck of a good boondocking/trailriding helix. Tom Hartman made a lot of money off that setup. The problem came when hill climbing the sled would drop from 10,500 RPM to 9,500 RPM.

The last few years I have used a shockwave adjsutable helix on the sled.

http://www.shockwaveperformance.com/

It allows you to turn up the helix angle at lower elevations (because you have the power to pull the higher angle and thus engine load down low) and as you gain altitude and lose hp you can dial down the helix angle to enable you to still be able to hit your target RPM as your sled loses 3% of its horsepower every 1,000 feet of elevation (unless you have a turbo).

Before this adjustable helix I had to compromise. After it, I was always hitting 10,500 RPM climbing regardless of elevation because I was able to reduce the helix angle to a load the engine could pull.

How are things different with a diamond drive?

 

[Wood]

My experience with my M7 matches Wyoboys's...steeper helixes backshift faster, but load the motor to much climbing, sometimes.

Frostbite, that BD helix is probably a progresive, no? I'll post the tracing I did of a couple of helixes, including a BD 46-36 progressive. Notice the progresive is still pretty steep, well after the 44-40 has transitioned. I found this helix too much for my stock M7 to pull while climbing (with the goodwin blue), but it was wicked fast on hardpack.

My experience, yours may vary.
John

Steeper helix will upshift faster/backshift slower.

Frostbite, there are no adjustable helix options for the DDrive clutches.

 

[furthur]

On the drawing, I have marked where the 44-40 and 42-36 transition (squiggly lines with arrows, pointing above the line labeled "start shift"). You can kinda see the progressive curve arc out beyond the other three helix tracings. Where the other helixes tansition to shallower angles, you can see that the progressive (once you find it), is still fairly steep.

You can see where I've marked 1.62:1, just above the transitions points of the 44-40 and 42-36. This is the point I calculated to be about 45 mph trackspeed at 7700-7800 rpm. I know I don't wanna be steeper than 40 deg. here, and 38 is better, by my testing. The progressive is too steep here, for me. That's the point of the whole trace...to prove to me what my testing showed...that the 46-36 progressive was too much helix for my M7. The point of my posting it was to show that progressive helixes carry steep angles out quite aways past the normal transition points on conventional two-angle helixes (the 44-40 and 42-36 are stock AC helixes).

The goodwinn blue-orange may well work out just fine for that helix. My bet, though, is that you will gain backshift and rev's climbing, but loose speed and over rev on top-end, due to inability to shift out against that spring. I don't have any recomendations for you, but if i were trying to clutch that sled, I'd start with a spring that was 200 -280lbs at 2.9"& 1.6", or try a shallower inital angle. You could also swap to an adjustable endcap style, and add more preload, but it's the same as putting in a stiffer overall spring...you will limit total shift if you have too much secondary spring force.

That, BTW, is how to adjust DD sleds for altitude...the adjustable endcap can add secondary preload to help a setup that's optimized at a lower altitude.

John

 

[Frostbite]

Thank John. I think I understand a little better now.

Where does a guy get one of the adjustable end caps?

It would be nice to have the adjustability.

"The goodwinn blue-orange may well work out just fine for that helix. My bet, though, is that you will gain backshift and rev's climbing, but loose speed and over rev on top-end, due to inability to shift out against that spring".

How can I help shift out against the Goodwin stouter secondary spring? I would think that with the fairly low 36 degree finish angle of the helix that I should be able to achieve full shift out? Maybe?

 

[mike800]

Solve your problems by going torsional.

All the Cat helixs from BD are step-cut, I called BD during a week they were cutting and had a progressive made to my spec.

 

[Frostbite]

Oh no, not step cut!

That could cause problems for sure with the rollers just barely hanging up on a step when the sled really would like to shift for optimum performance.

Yes, progressive helixes are the only way to go. I tried that with the Dalton helixes I was testing. I hated the step cut but, loved the progressives.

I though I read that the torsional setups (I.E. RK TEK) weren't working on the 09 sleds. I remember reading where people (not me) were at least blaming these setups for belts flipping over and breaking on the 09s.

Was that really an issue?

Was it ever solved?

 

[Wood]

Oh no, not step cut!

That could cause problems for sure with the rollers just barely hanging up on a step when the sled really would like to shift for optimum performance.

Yes, progressive helixes are the only way to go. I tried that with the Dalton helixes I was testing. I hated the step cut but, loved the progressives.

I though I read that the torsional setups (I.E. RK TEK) weren't working on the 09 sleds. I remember reading where people (not me) were at least blaming these setups for belts flipping over and breaking on the 09s.

Was that really an issue?

Was it ever solved?

You will never hang up a roller on a 'step' cut DD cam. The double angle (typical) cams will only run the first angle for about 3/4" and then it's straight to the finish angle for the rest of the shift. The only time I have ever encountered this was with quad angle step cut cams and button clutches where the buttons were hanging up on the last transition.

Torsion setups causing belts to flip over???? Where are you getting your info?

 

[spanky]

spring chart

Thanks for the info. D drive is hard to clutch. also found crazy fast chit on the hard pack. Never have found the perfect set up.

 

[RKT]

Oh no, not step cut!

That could cause problems for sure with the rollers just barely hanging up on a step when the sled really would like to shift for optimum performance.

Yes, progressive helixes are the only way to go. I tried that with the Dalton helixes I was testing. I hated the step cut but, loved the progressives.

I though I read that the torsional setups (I.E. RK TEK) weren't working on the 09 sleds. I remember reading where people (not me) were at least blaming these setups for belts flipping over and breaking on the 09s.

Was that really an issue?

Was it ever solved?

Belts flipping over due to clutch kit?? Not possible.. The only way to have a belt flip over is to install the wrong length belt. There is NO WAY ANY clutch kit can cause this sort of problem..

As for my kit not working on the 09 models.. Another fine example of internet mis-information..

We have over 2600 HARD miles on our 2009 M8.. Kit works excellent..

In fact they "Suck" so bad, that we have had to make 2 special production runs lately just to keep the 09 customers happy..

Please do not believe everything you "hear" or "read" on ANY public forum.. If you believed everything you read on public forums.. you would hardly get any riding in due to all the "problems" with sleds..LOL

Kelsey

 

[WyoBoy1000]

So what works on the 09 m1000 I feel i'm missing about 30% of my power on the top end, due to to much backshift. Sled snaps right to it but once on a pull it slows and holds and wont wind back up until I pick up a lot more speed. also loosing to much rpm when it slows in my opinion. I think with a softer finish on the secondary I would gain but then I would have to go through the motions on the primary as well, kinda getting sick of it. Don't get me wrong the sled isn't getting beat so its doing quite well but I am very picky and can feel the full length of engagement and there is more on the table but I know I don't have the $$ to keep trying everything to find the perfect balance unless I get lucky. My 07 with stock clutching pulled hard and smooth and never let up( not sure how it worked so well) but the 09 is a complete different story. the sled also snaps right up to 85mph then slows my 07 would rip all the way to 95 then slow.

 

[Frostbite]

Kelsey, I'll try to find the picture I saw of a flipped over belt. There were several pictures of broken belts as well on the post I'm thinking of on the subject. I thought I saw it on this forum but after a short search, I can't seem to find it right now. I may have been on another forum, I'll do some searching.

I'm certainly not trying to hack on your products. In fact, I think they are great but, I did read there were plenty of issues initally in trying to get the torsional setup to work properly on the 2009 models.

If a torsional setup is the way to go, then deal me in. If not, I'm make the best of the stock setup using a shift assist kit, the most friendly helix and the most snappy secondary spring.