Stock/ish 10-11 M8 clutching setups

[GlennRMK]

Curious what people are doing.

I have 11 M8 Sno Pro 153. Stock except for a Cutler can. Stock yellow/white primary w/68s and stock orange secondary with 36 deg helix.

I was riding around 8500-9000 ft today and the RPM seemed spot on at 8000-8100 RPM and holding there. Had a foot of fresh on a real good base and track speed seemed to hover around 43-44 MPH.

Gotta be more track speed to be had???

What are people doing?

I was thinking of trying 70s and blue/pink SLP spring. Or trying 40/36 or 42/36 helix?

Any other weights provide better track speed? SLP MTX, Cutler, etc?

I'm looking for track speed comparisons and holding RPM. Don't care about drag racing.

 

[dfinn]

If that was in an uphill climb with a foot of fresh I'd say you're doing pretty good. Is there really more track speed to be expected? I'm getting about the same as you, CPC 65 - 75G weights almost empty, just a small amount of weight in the tip and SLP Black/Pink primary spring.

 

[JHG]

More RPM, that sled needs to be between 8100-8300.

 

[skidooboy]

if you need a few more rpms dont drop weight in the arms, add a high finish rate on your primary spring.

tune the rpms with the primary. tune the upshift and backshift with the secondary. trying to change rpms with secondary, is only robbing peter to pay paul. ski

 

[winch_warrior]

I have 11 M8 Sno Pro 153. RKT secondary kit with Kelsey's 36/34 helix and his custom secondary spring. Stock yellow/white primary w/67.3's at
10,000 ft and 8150-8200 RPM. Quite a bit of difference with track speed, really noticeable on long steep pull.

 

[Rprecision]

Pulling stock 62's, cutler gold spring, and the same RKT set up as above

8250-8275 on a climb w. 45-47 Mph. It pulls hard and never seems to hit a wall

 

[GlennRMK]

Yes, snow was a solid foot or better of powder on a good pull @ 8500-9000 ft.

Winch Warrior, what kind of track speeds?

Everyone says run them 8100-8300 but dynos say otherwise. Dynotech dyno'd the 10 Crossfire and #s are as follows

7700 153.5 hp and 104.7 ft lbs
7800 156.8 hp and 105.6 ft lbs
7900 158.9 hp and 105.6 ft lbs
8000 159.7 hp and 104.8 ft lbs
8100 159.1 hp and 103.1 ft lbs
8200 156.7 hp and 100.4 ft lbs
8300 150.9 hp and 95.5 ft lbs

Seems to me your better off running 7800 RPM then 8200 RPM. I'm at 8050 or so consistently. Seems to be the sweet spot reading via dyno.

Not sure what effect 9000 ft elevation plays though. Be interesting to see a dyno at that elevation.

I may try the SLP Blue/Pink next ride and try to compare track speeds and RPMs.

I just started at a local Cat dealer and we have a a Cutler torsion setup with a 38 helix and green spring sitting on the shelf but $300 is some coin to drop which I could put into something else.

We also have (3) 2011 800s between myself and a couple guys I work with and we are all trying different things to find the best clutching setup.

I had a torsion setup in my 09. I never really saw much increase in trackspeed just a backshift improvement.

The motor in my 2011 is so much snappier I don't know that I need more backshift. I really want it to pull harder and almost seems I could load the motor harder and could maybe use more upshift.

 

[06m7]

do polaris springs fit good in cat primary

 

[AKSNOWRIDER]

Yes, snow was a solid foot or better of powder on a good pull @ 8500-9000 ft.

Winch Warrior, what kind of track speeds?

Everyone says run them 8100-8300 but dynos say otherwise. Dynotech dyno'd the 10 Crossfire and #s are as follows

7700 153.5 hp and 104.7 ft lbs
7800 156.8 hp and 105.6 ft lbs
7900 158.9 hp and 105.6 ft lbs
8000 159.7 hp and 104.8 ft lbs
8100 159.1 hp and 103.1 ft lbs
8200 156.7 hp and 100.4 ft lbs
8300 150.9 hp and 95.5 ft lbs

Seems to me your better off running 7800 RPM then 8200 RPM. I'm at 8050 or so consistently. Seems to be the sweet spot reading via dyno.

Not sure what effect 9000 ft elevation plays though. Be interesting to see a dyno at that elevation.

I may try the SLP Blue/Pink next ride and try to compare track speeds and RPMs.

I just started at a local Cat dealer and we have a a Cutler torsion setup with a 38 helix and green spring sitting on the shelf but $300 is some coin to drop which I could put into something else.

We also have (3) 2011 800s between myself and a couple guys I work with and we are all trying different things to find the best clutching setup.

I had a torsion setup in my 09. I never really saw much increase in trackspeed just a backshift improvement.

The motor in my 2011 is so much snappier I don't know that I need more backshift. I really want it to pull harder and almost seems I could load the motor harder and could maybe use more upshift.

one thing that a dyno sheet doesnt show..the hill and the effect it has on pipe temps....regardless of what the dyno says..you need to check max rpm performance on the hill from at least the max rpm power showed on the dyno, all the way up to revlimiter or you feel the power taper off...then you will know exactly what rpm your setup performs best at...you would be surprised what 200 more rpm might produce on the hill vrs what the dyno sheet shows......just what I have found over the years....

 

[Woody67]

one thing that a dyno sheet doesnt show..the hill and the effect it has on pipe temps....regardless of what the dyno says..you need to check max rpm performance on the hill from at least the max rpm power showed on the dyno, all the way up to revlimiter or you feel the power taper off...then you will know exactly what rpm your setup performs best at...you would be surprised what 200 more rpm might produce on the hill vrs what the dyno sheet shows......just what I have found over the years....

great point. One of my customers is going to test the new D&D mountain pipe for the 800 HO and I asked Dale about the dyno numbers and RPM. He said because of the difference in the pipe and pipe temps be sure to spin the M sled with this pipe at 8150-8250.

 

[AKDMAX1]

do polaris springs fit good in cat primary

I ran a polaris almond (140-330) but didnt like it, BUt it fit pretty well.

 

[Destroyer]

Curious what people are doing.

I have 11 M8 Sno Pro 153. Stock except for a Cutler can. Stock yellow/white primary w/68s and stock orange secondary with 36 deg helix.

I was riding around 8500-9000 ft today and the RPM seemed spot on at 8000-8100 RPM and holding there. Had a foot of fresh on a real good base and track speed seemed to hover around 43-44 MPH.

Gotta be more track speed to be had???

What are people doing?

I was thinking of trying 70s and blue/pink SLP spring. Or trying 40/36 or 42/36 helix?

Any other weights provide better track speed? SLP MTX, Cutler, etc?

I'm looking for track speed comparisons and holding RPM. Don't care about drag racing.

You won't pull 70's at that elevation. I'm 2500'
73 grams,
slp blue pink
straight 36 orange spring.
holding 8050 ish. And doesn't rev up fast enough. Might try the 71.5's.

I don't want to change helix's when I go west so I was thinking a 40/36 might serve me better.

 

[AKDMAX1]

I run 0-3000 and run the yellow/white with 71.5g and the orange with the 36* and it flat out rips and hold 8150 all day long.

 

[GlennRMK]

Destroyer and AKDMAX1, do you have 10s or 11s?

It seems like the 11s are pulling more weight. My 11 and a co worker of mine has an 11 and both are pulling 68s at around 8100 RPM at 8000-9000 ft (both 153s).

Last year he had a 10 153 and to drop weight to 66.5s to get the same RPM.

I feel pretty good about pulling 68s at 9000 ft with only 150 miles on my sled if your running 71.5 at 3000 ft.

 

[Destroyer]

Mines a 2010 That's what I thought. 68's with the slp blue pink ran good out west. 8100-8150 solid tach on a long climb. But for some reason it doesn't want to pull that bit more weight at 2500'. The 2010 crossfires ran 68's at 0-3000 with the 060 belt. So I tried that. Sled ran good wot rpm. but just to "revy" on the bottom.

With the 73's and slp B/P It pulls it good on wot rpm. A solid 8050-8100 is close. I just need it to upshift a little quicker on the bottom. Feels hesitant off the get go.

 

[dfinn]

Everyone is talking about rpms but no one mentions track speed. I've found that it's pretty easy to get your sled to pull more rpm while at the same time bringing track speed down, I've also been able to do the reverse of that too. I now pay more attention to track speed.

 

[fastlane]

Dyno numbers are just for reference ie. "changed pipe and now this pull we have 4 more horse than the last" We always dynoed our modified engines just for breakin/leaks.issues etc.. the dyno sheet would always say max torque would be like 5800 and max hp 7500 after that it would fall off the map on power, but on the track if you turned it 7500 it felt like you were tied to a pole, at 8200-8400 felt like it had two motors under the hood, reguardless what the dyno says the real world performance on the track or hill is what matters, same for a racecar or a snowmobile...

 

[winch_warrior]

Went up and did a little more testing this morning after lightening up primary weights last night to 67 grams-stock Cat weights- 2011 M8 Sno Pro 153. Running 10,000 ft. elevation and now pulling 8200-8250 for RPM. This RKT secondary kit rocks! I'm not testing across lakes....only long steep pulls to check backshifting and track speed- 6" fresh snow. All I can say is WOW! Track speed is a solid 4-5 mph faster than stock cat secondary. The backshift is really,really noticeable up steep pulls.
Stock sled except for this RKT secondary kit and HPS can.

 

[Dam Dave]

Went up and did a little more testing this morning after lightening up primary weights last night to 67 grams-stock Cat weights- 2011 M8 Sno Pro 153. Running 10,000 ft. elevation and now pulling 8200-8250 for RPM. This RKT secondary kit rocks! I'm not testing across lakes....only long steep pulls to check backshifting and track speed. All I can say is WOW! Track speed is a solid 4-5 mph faster than stock cat secondary. The backshift is really,really noticeable up steep pulls.
Stock sled except for this RKT secondary kit and HPS can.

what pri spring, what spring/helix in RKT sec kit

 

[winch_warrior]

Same as I posted last night earlier in this thread.......Stock yellow/white primary with Kelsey's 36/34 helix and his custom secondary spring.