RPM

dktraw · Feb 10, 2019

Where are you RMK guys finding the sweet spot for rpm? I have been playing with clutching and finding different results than a lot of aftermarket company's are claiming. They claim 8100 is best power, but my sled so far seems to run considerably better at 83-8400. Sled feels slow and tractorish when clutched for 8100. At 8400 track speed is significantly higher, and sled is getting on top of the snow and just feels much faster. Im currently using the SLP magnum force weights but not sure yet if I like them. Im planning to do a some more testing this week so I thought Id see where you guys are aiming.
My sled
19 850 155 2.6 just under 600mi
I weight 260 with gear, and always have 3 gal of fuel on tunnel (until end of day anyways:face-icon-small-hap)

Edit:
little more clarification on rpm. this is for rpm while track is fully buried in snow and motor loaded hard for long pulls. this is not track outa snow wheelie tach blipping to 8300 once in awhile. when I say im clutched for 83-8400 I will see 85-8550 at various times, but full pull she settles in and holds 83-8400. and vise versa, when im clutched for 8-8100 I will see 8300 on the tach, then settle and pull 8100.

dktraw · Feb 11, 2019

Sooooo, nobody else has been moving the rpm around to find the best power??

m1kflyingtiger · Feb 11, 2019

My clutch kit says to shoot for 8300-8400 on it. Seems good thee but haven’t walked it down to 8100 yet.

dktraw · Feb 11, 2019

Who's clutch kit are you running?

m1kflyingtiger · Feb 11, 2019

A2Dsledworks our of anchorage, ak.

tdbaugha · Feb 12, 2019

On the dyno, cold pipe peak power is at 8100, hot pipe is 8300.

snobyrd · Feb 12, 2019

dktraw said:
Where are you RMK guys finding the sweet spot for rpm? I have been playing with clutching and finding different results than a lot of aftermarket company's are claiming. They claim 8100 is best power, but my sled so far seems to run considerably better at 83-8400. Sled feels slow and tractorish when clutched for 8100. At 8400 track speed is significantly higher, and sled is getting on top of the snow and just feels much faster. Im currently using the SLP magnum force weights but not sure yet if I like them. Im planning to do a some more testing this week so I thought Id see where you guys are aiming.
My sled
19 850 155 2.6 just under 600mi
I weight 260 with gear, and always have 3 gal of fuel on tunnel (until end of day anyways:face-icon-small-hap)

Edit:
little more clarification on rpm. this is for rpm while track is fully buried in snow and motor loaded hard for long pulls. this is not track outa snow wheelie tach blipping to 8300 once in awhile. when I say im clutched for 83-8400 I will see 85-8550 at various times, but full pull she settles in and holds 83-8400. and vise versa, when im clutched for 8-8100 I will see 8300 on the tach, then settle and pull 8100.

Im also using slp weights but the mtx 74s (73.2) with 1 grm added in both tip and mid. im seeing 48/49 mph when im chopping the throttle ,goin up through trees at 6000 feet, im pulling 82/8350 rpm.
What is your track speed? Do you find your bottom end stronger and more responsive?

dktraw · Feb 13, 2019

Im not seeing that track speed. Depending on snow conditions, In the tree's im 38-40 on deep days. I can maybe see 43-45 at times. This is 7-8k ft elevation. I am not happy with the SLP magnum force weights. They dont have enough belt squeeze. Had belt marks all over my sheeves. Swapped on the mountain yesterday back to 10-68s and clutches cleaned up immediately. Rpm was better also. Yesterday was arm pit deep and i was only getting 81-8200 consistently. Gonna change secondary setup for today, really feel like the secondary was not backshifting worth beans yesterday....was still going better than my bros 850 Doo though!!

snobyrd · Feb 13, 2019

dktraw said:
Im not seeing that track speed. Depending on snow conditions, In the tree's im 38-40 on deep days. I can maybe see 43-45 at times. This is 7-8k ft elevation. I am not happy with the SLP magnum force weights. They dont have enough belt squeeze. Had belt marks all over my sheeves. Swapped on the mountain yesterday back to 10-68s and clutches cleaned up immediately. Rpm was better also. Yesterday was arm pit deep and i was only getting 81-8200 consistently. Gonna change secondary setup for today, really feel like the secondary was not backshifting worth beans yesterday....was still going better than my bros 850 Doo though!!

How many grms are you running with the slp? With my setup, all off the weight is in the heal thus giving good belt squeeze in the bottom end. My bottom end is pretty solid.

dktraw · Feb 13, 2019

I tried everything from no set screws 60.7grams to full set screws 68.5grams. At full weight i was only 79-8000rpm and very sluggish. At 66.7 grams was best performance but still not as good as stock 10 series weights. These are 61grams empty and think they are to light to start with. I think the heavier ones might work better in the 850. There 65grams empty and might grip the belt better. But dropping another 200 bucks on a maybe is hard to swallow. Im putting the SLP weights in my 17 800today to see how they work in that

snobyrd · Feb 13, 2019

dktraw said:
I tried everything from no set screws 60.7grams to full set screws 68.5grams. At full weight i was only 79-8000rpm and very sluggish. At 66.7 grams was best performance but still not as good as stock 10 series weights. These are 61grams empty and think they are to light to start with. I think the heavier ones might work better in the 850. There 65grams empty and might grip the belt better. But dropping another 200 bucks on a maybe is hard to swallow. Im putting the SLP weights in my 17 800today to see how they work in that

Did you follow slps recomendations?
Iv always run mtx since 2013 on my pro and 16 axys, i Buy them as heavy as i can without adding to much weight. i ran the 72s empty in my axys 800.

dktraw · Feb 13, 2019

Yes, followed there recommendations. I even asked about the weights being to light and they said no way, the 65s would be to heavy.

dktraw · Feb 14, 2019

The slp magnum force weights seemed to work really well in the 800 yesterday. Had the blue/pink spring per slp specs, and had loaded with 1 set screw and 1 lock screw, think it came out to 63.1g total weight. Had plenty of belt squeeze and was getting 8300rpm. So im thinking maybe the 61g base weight might be to light for the extra torque of the 850?? Any other thoughts? Like the weight if i can get it to grip the belt

TRS · Feb 15, 2019

The new .......16 belt is hard to get ahold of in the primary. 3g more than a Gates belt.

dktraw · Feb 15, 2019

Wow! Thats good to know, thanks!

ak · Feb 15, 2019

If you do need more tip weight, tungsten slugs fit right in the tip on the magnum force weights.

dktraw · Feb 15, 2019

Where are you buying the slugs?

dktraw · Feb 16, 2019

Well i need to back track and eat a little crow....i wasnt super happy with performance of sled last 2 days compared to how it had been running earlier. Started cleaning clutches and found a roller in primary clutch starting to go bad. Dealer yesterday replaced complete primary and gave me a new belt! I had also been experiencing hard starts after working sled hard so they did the new updated mapping also.
So the bad review and poor performance of the slp magnum force weights might not have been completely the weights fault. Im going to give them another go and see how they do. Riding Sunday and Monday so ill report back after that.

Teth-Air · Feb 16, 2019

I did the fuel map update and then gained 150-200 rpm and then had to add more clutch weight. So if you are clutching you may want to do the fuel map first.

dktraw · Feb 16, 2019

Thats the plan. Sunday i will ride with all stock clutching to get a new baseline with the new fuel map. Then Monday i will try the SLP setup

RPM

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