##2021 Season Low snow mod update-video##Another (better?) no weld solution for tunnel shortening.

[Murph]

Still hoping for a before and after weight.

MTNTK 5’ cooler 7.4 lbs (3.4 kg)
Cut off tunnel 1.6 lbs (.7 kg)

net weight GAIN 5.8 lbs. (2.7 kg)

 

[DITCHBANGER]

Thanks murph. So that would be plus one more gallon of coolant? Mtntk says stock 1 gallon and 5ft is 2 gallon.

 

[Murph]

Thanks murph. So that would be plus one more gallon of coolant? Mtntk says stock 1 gallon and 5ft is 2 gallon.

Correct. That was empty cooler weight vs empty tunnel cut/ coolant crossover weight.

I'm planning on doing the same thing to my 2021 165-- I was happy with the result.

 

[Jaynelson]

At a glance from your measurement pic, it looks like you could start with a 155" sled, use this 5' cooler and still be able to cut off 5-6" or better eh?

 

[Murph]

At a glance from your measurement pic, it looks like you could start with a 155" sled, use this 5' cooler and still be able to cut off 5-6" or better eh?

Yes.

 

[klarkkentster]

@Murph curious if you felt much of a difference in sleds ability... change/improvement in sidehilling? Deep snow?

 

[Murph]

@Murph curious if you felt much of a difference in sleds ability... change/improvement in sidehilling? Deep snow?

Somehow I missed this.

Deep snow— sled keeps churning and digging while driving forward.

Sidehilling— on steep sidehills, you have to actively control the sled a little more because you don’t have the tunnel acting as a rudder in the snow.

 

[Murph]

###Update 20-21 Pre-season prep###

Bottom of cooler after 1500 miles— no rubbing.

Members asked to see the hose arrangement

 

[Sheetmetalfab]

Somehow I missed this.

Deep snow— sled keeps churning and digging while driving forward.

Sidehilling— on steep sidehills, you have to actively control the sled a little more because you don’t have the tunnel acting as a rudder in the snow.

^^^^^ I’ve noticed the same.

Also re entries are much easier.

No flap, no tunnel to hangup.

Fun and wild ride.

 

[Murph]

⬇⬇⬇⬇⬇⬇⬇2020-21 Season update/ modification for low snow conditions ⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇

 

[nibrandon]

⬇⬇⬇⬇⬇⬇⬇2020-21 Season update/ modification for low snow conditions ⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇

Are the holes intended to allow for better cooling through snow on top of the tunnel? Did you find it necessary to get more cooling than the 5' cooler offered by itself?

 

[Murph]

Are the holes intended to allow for better cooling through snow on top of the tunnel? Did you find it necessary to get more cooling than the 5' cooler offered by itself?

In every situation other than hardpack spring conditions, I found the 5' MTNTK cooler running lower temps than stock 850 163s with stock cooling systems. I use my sled for Search and Rescue and late season riding/ recues can see me out in less than ideal conditions (1/2- 1mile stretches of bare asphault or dirt) where even stock sleds struggle. The normal method of packing snow on the tunnel doesn't help because the snow is not sitting on the cooler itself. These holes will allow me to pile snow up on the cooler directly. Someone else raised the question of "structural integrity" I'll post a video of a stock tunnel versus my tunnel with the MTNTK cooler-- the MTNTK cooler equipped sled is significantly stiffer.

stock tunnel


MTNTK cooler equipped tunnel


It’s hard to distinguish through video but in person the MTNTK equipped tunnel is WAAAY stiffer— ribbed extrusion vs flat aluminum sheet.

 

[MKULTRA]

if polaris ribbed the stock cooler I'm curious how much more cooling the stock system could do. I mean they could triple the surface easily.

 

[pepperhouse]

Exactly ribs cost nothing.
We have noticed a difference in cooling even between painted vs non painted tunnels

 

[Murph]

We have noticed a difference in cooling even between painted vs non painted tunnels

Yep. I’ve always wondered how much heat a wrap holds in.

 

[couch]

Luv it!!! Chopped 10" off the tunnel - will see if xtra cooler is warranted - if so the hole saw will come out too!!

Sent from my LG-H873 using Tapatalk

 

[klarkkentster]

In every situation other than hardpack spring conditions, I found the 5' MTNTK cooler running lower temps than stock 850 163s with stock cooling systems. I use my sled for Search and Rescue and late season riding/ recues can see me out in less than ideal conditions (1/2- 1mile stretches of bare asphalt or dirt) where even stock sleds struggle. The normal method of packing snow on the tunnel doesn't help because the snow is not sitting on the cooler itself. These holes will allow me to pile snow up on the cooler directly. Someone else raised the question of "structural integrity" I'll post a video of a stock tunnel versus my tunnel with the MTNTK cooler-- the MTNTK cooler equipped sled is significantly stiffer.

stock tunnel


MTNTK cooler equipped tunnel


It’s hard to distinguish through video but in person the MTNTK equipped tunnel is WAAAY stiffer— ribbed extrusion vs flat aluminum sheet.

I'm not able to view the videos. Are they available on YouTube as well?

 

[ullose272]

How much tunnel can you cut off on a 155?

Sent from my SM-G973U using Tapatalk

 

[Murph]

I'm not able to view the videos. Are they available on YouTube as well?

Missing Digit Motors —Murph—

Snowmobile performance shop working exclusively on 2016 and newer Polaris ProRMK snowmobiles. Turbo installs, Khaos conversions, tunnel shortening. Dealer fo...

www.youtube.com

 

[Murph]

How much tunnel can you cut off on a 155?

Sent from my SM-G973U using Tapatalk

With a 5’ cooler, probably 6-8”... I’ve got a couple of 155s in the shop. I’ll try to remember to measure them for you.