2014 Pro rmk 163 clutching

[benltr]

Hi guys,

Mods on the sled :

hps can
mds clutch kit for sea elevation 0-3000
28$ mod
non eth mode
oil pump turned up

Here is a two quick video of my playback on a straight line, semi hardpack trail :

https://www.youtube.com/watch?v=h93CvRC5c9g
https://www.youtube.com/watch?v=gCJU62Tf22A

Both test were done on the same condition and trail.

The first one is with the Hex bolt + 2 washers on the tip and the black bolt (non drilled) on the second spot. That's about 72,8 grams

The second run is with the Hex bolt + 2 washers on the tip and an another hex bolt on the second spot. That's about 74,5 grams.

As you can see on the trail the rpm is not bad except between 0-80 km/h and start to get spot on at 100 km/h (60 mph).

I didnt test the first setup on deep snow or uphill with powder. But i tested the second setup (74,5 grams) on the deep snow going uphill and i think i hit max of 7800 rpm with some drop to 7600-7700 depending on what was under the snow (trees, rocks, etc...)

What do you think or what should i do? Clutch it for the spot on rpm on the trail or clutch it for the deep snow? If i clutch for deep snow i might hit like 8400-8450 on the trails... Any tips will be appreciated.

Also what you guys target for rpm? 8100-8200?

 

[2XM3]

what helix are you running ? and what secondary spring?

 

[benltr]

stock helix and 110/290 black polaris spring

 

[2XM3]

heres a great thread on clutching, id probably go black purple spring with a helix around 62 42 .46 also buy aaens book on clutching (ebay) good stuff


http://www.snowest.com/forum/showthread.php?t=128754

 

[sledneck_03]

Hi guys,

Mods on the sled :

hps can
mds clutch kit for sea elevation 0-3000
28$ mod
non eth mode
oil pump turned up

Here is a two quick video of my playback on a straight line, semi hardpack trail :

https://www.youtube.com/watch?v=h93CvRC5c9g
https://www.youtube.com/watch?v=gCJU62Tf22A

Both test were done on the same condition and trail.

The first one is with the Hex bolt + 2 washers on the tip and the black bolt (non drilled) on the second spot. That's about 72,8 grams

The second run is with the Hex bolt + 2 washers on the tip and an another hex bolt on the second spot. That's about 74,5 grams.

As you can see on the trail the rpm is not bad except between 0-80 km/h and start to get spot on at 100 km/h (60 mph).

I didnt test the first setup on deep snow or uphill with powder. But i tested the second setup (74,5 grams) on the deep snow going uphill and i think i hit max of 7800 rpm with some drop to 7600-7700 depending on what was under the snow (trees, rocks, etc...)

What do you think or what should i do? Clutch it for the spot on rpm on the trail or clutch it for the deep snow? If i clutch for deep snow i might hit like 8400-8450 on the trails... Any tips will be appreciated.

Also what you guys target for rpm? 8100-8200?

I have same sled, at 1500 ft

my mds weights are hex bolt and one washer in tip and drilled bolt in mid.

I have a 125/280 epi white in it. It runs 8300 on trail and 8100-8200 in powder.

reason i run the epi white it $26 and i can buy them from the local store 5 minutes away. Polaris 100/290 springs are $56 and have to order them.

the 125/280 epi white measured at 2.5/1.25 but if you calculate is at 2.5/1.19 like the polaris spring its a 125/287 so very close, just kicks in a little higher rpm.

 

[benltr]

Yes i had that setup at first (its what they suggest) but i was kinda over rev in the trail...

I use the 110/290 spring in the PAR kit.

I removed the hex bolt and put the black bolt non drilled on the second spot and i kept the hex bolt + 2 washer on the tip... i'll see what it does this weekend.