• Don't miss out on all the fun! Register on our forums to post and have added features! Membership levels include a FREE membership tier.

RMK 800 PRO Mods?

K
Dec 2, 2007
177
2
18
52
Drumheller, Alberta
I snow checked a new 800 RMK 163 pro. Sold my turbo four stroke. Want to pull a reliable extra 15-20 hp out of the 800 plus add a small hit of nitrous. What have other owners been doing for mods that work.

Thanks in advance!
Casey
 

F-Bomb

SnoWest Paid Sponsor
Premium Member
Nov 26, 2007
2,598
821
113
South West Idaho
www.f-bombracing.com
Power Addiction Head 13.1 if you are riding 3000-5500 or 13.6 if you spend your time at 5500-up

Clutch Kit from Carl's Cycle Sales in Boise Idaho

Trim your stock 5.1 Polaris track to 2.1"

Do these three simple things and make your PRO outstanding! Stock shocks are seriously wanting as well in all aspects of performance. I did a Fox Evol R front and Evol R with Zero Pro/ Ti spring rear system that is second to nothing that I rode all last season.


attachment.php
 

Attachments

  • PRO LIC photo shoot 1.jpg
    PRO LIC photo shoot 1.jpg
    185.4 KB · Views: 6,439

AndrettiDog

Well-known member
Lifetime Membership
Dec 23, 2007
6,329
2,478
113
Colorado
I know the CFI4 had excellent gains with a high compression head and I'm hoping that the CFI2 does the same without deto issues and without the need of race fuel. That could be wishful thinking, but that lightweight chassis would rip with a few more HP.

This is the best sled I've ever had out of the box. Shocks are a little soft though.
 

gmustangt

Well-known member
Lifetime Membership
Aug 10, 2009
1,443
495
83
You could look into slp' s stage 3 kit for the pro, bolt on and gives you an extra 15hp.
 
T

traveler

Active member
Apr 30, 2008
200
30
28
Evergreen
Dynotech research

Join Dynotech reasearch look at the graphs they have done on stock and mod 2011 polaris 800's.
167 hp 106 ft/lbs w/ cyl shim, timming key and pipe.

http://www.dynotechresearch.com/index.htm

Hey KC, I remember you, you were going to sell me a SC for my Nytro, welcome to the club.
 
Last edited:
K
Dec 2, 2007
177
2
18
52
Drumheller, Alberta
Join Dynotech reasearch look at the graphs they have done on stock and mod 2011 polaris 800's.
167 hp 106 ft/lbs w/ cyl shim, timming key and pipe.

http://www.dynotechresearch.com/index.htm

Hey KC, I remember you, you were going to sell me a SC for my Nytro, welcome to the club.

I do remember now. Ya the SC was an adventure that went really wrong really fast, so I took the SC off and put the turbo on. The turbo ripped (340hp) but you just cant have fun boondocking. Time to focus on light weight and agility again. Hope to get to 410-420 lbs dry with my 163 pro and 165-170 hp.
 

F-Bomb

SnoWest Paid Sponsor
Premium Member
Nov 26, 2007
2,598
821
113
South West Idaho
www.f-bombracing.com
There is no handicap in any type of snow tested heads up versus a bone stock 5.1 irregardless of depth or water content. You do get exponentially higher performance with higher water content or more packed the snow conditions.

The reason for this on this particular vehicle is because the drag from resistance of windage and evacuation space cannot be overcome by the 800's limited HP. IE A balance of pattern, throw, evacuation and windage in use with the amount of power/force available is what propels the vehicle. On this vehicle you get better performance with less drag resistance. To compete in net performance you have to add significant HP to overcome the resistance.

Camoplast (the contracted manufacturer for Polaris) knows this and it's been clearly proven over and over on this application. The problem is the consumer is ignorant and marketing demand drives design. Guys would stuff 3" paddles plus in there if they would rotate at all! Add more HP and more evacuation space to lessen resistance and you'd would have a performance increase but as things stand right now on this application 2.1" is the perfect setup and that is why I coach people to do this. It gives you free performance over your buddies' stock application all day every day.
 

mountainhorse

Well-known member
Lifetime Membership
Premium Member
Dec 12, 2005
18,606
11,814
113
West Coast
www.laketahoeconcours.com
Since the timing seems to play such a vital role in the DTR runs... I'm wondering what the results would be with stock exhaust, stock head, no shim BUT adding the timing key and the PC-5?? (no speculation.... just a real world test)
 
K
Dec 2, 2007
177
2
18
52
Drumheller, Alberta
Would there be an advantage to cut a V down the paddles in the center of each row to allow for air evacuation. We used to do that with the old plastic paddles. (WOW that was dating myself)lol. Keep the opinions coming, myself and others are needing opinions. Thanks
 

F-Bomb

SnoWest Paid Sponsor
Premium Member
Nov 26, 2007
2,598
821
113
South West Idaho
www.f-bombracing.com
Well if you ask Polaris or Camoplast they will tell you the 5.1 is the same and I've always installed stiffening screws on the 5.1. BUT...when the PRO showed up last year studying it directly next to my 09 the track appears stiffer. So I simply trimmed it first but no screws to compare. It throws and feels identical to my old 5.1 with inset screws. Now the two sleds are totally different so you couldn't conclude anything against one another but they stood out similarly in their comparison to other like sleds in testing.

Windage and resistance are huge performance factors. It doesn't take much drag to have a significant effect on performance.

I trimmed a camo extreme on one of my sleds and it was outstanding as well. Once again same chassis situation on both the IQ RAW and the PRO..just not enough room and snort to efficiently spin that mass...as least not as good as the exact same track trimmed to 5.1 and what ever durometer or flex/throw you end up with on the old 5.1 with 1" inset screws or just trimmed on my PRO. Never did a direct comparison on a 5.1 155 versus a camo extreme trimmed (only non trimmed and the cut 5.1 was better). There is a snowest member from the midwest that bought a camo extreme 155 for an IQ and trimmed it...he liked the results or so he said.

I had such a good result from my trimmed stocker 5.1 on the PRO this past season that I consider it a done deal. I"m sure waiting for someone to come along and show me a significantly faster or better performing PRO with any kind of a track or track mod. It's gonna have to be something new because what was offered last year didn't do it.
 

AndrettiDog

Well-known member
Lifetime Membership
Dec 23, 2007
6,329
2,478
113
Colorado
Rob -> Did you have to make changes to the Pro stock skid? I ask because the limiter strap is not adjustable (w/o modifications) and the adjustment is mostly in the front shock. I've thought about making your mod to my Pro but the Pro isn't as bad with the 5.1 as the Dragon was. I'm sure some of your variables have something to do with that including weight and the transfer of the rear skid. I'd like to hook up quicker when climbing out of a hole or coming down hills. I might just try it. If it doesn't work, there are a ton of guys selling their 5.1's. If you see my signature, you can see I'm trying to find an old beater 5.1 to experiment with.
 

AndrettiDog

Well-known member
Lifetime Membership
Dec 23, 2007
6,329
2,478
113
Colorado
Since the timing seems to play such a vital role in the DTR runs... I'm wondering what the results would be with stock exhaust, stock head, no shim BUT adding the timing key and the PC-5?? (no speculation.... just a real world test)

Isn't the timing key relative to the shim?
 
Premium Features