121 converted to 136 doesnt want to plane off why?

[rab]

I coverted my 121 polaris dragon 07 to 136 similar to the 08 switchbacks and it doesnt seem to wanna plane off

I tried my buddies 136 and it planed better than mine and his suspension was stiffer and his is a 144 do you think that the suspension stiffness would affect the ability to plane off

If I was to some how try to move my front shock to help I think that I would have to lower the upper mounting point what do you think

Are there any books out there on this kind of stuff

 

[teeroy]

getting up on top of the snow requires a shallow attack or approach angle of the track, usually achieved by shortening the limiter strap. soften the front spring as well and give it a shot. might be all you need if you haven't tried it yet, it will give the front of the sled a "heavy" feel in the steering on packed snow too. (more ski pressure)

 

[LRD]

Just like teeroy said, you need a shallow attack angle on the front of the track for the sled to plane out and not trench. The short trackers may have steeper angle than the mtn sleds so Just Extending the rails won't really cut it for deep powder. Good attack angle will be in the 17 to 19 degree range, awesome would be even flatter. Short track may be 20 to 22 degrees or more. The longer the suspension travel the steeper it will get. If you move the front arm back in the tunnel which moves front of rails back it gets flatter but then your carying more weight on the skis and less on the track. Gets real interesting to get it to work right.

Good Luck

 

[polarpower]

The type of track plays a HUGE role in this as well. My Switchback, equipped with the stock 144" long 1.25" lug Camoplast Predator never planed out in the powder. It just trenched, trenched, and trenched. No suspension adjustments I made got rid of this. There was absolutely a day and night difference after switching to a 144" Camoplast/Polaris 2" lug Series 4 track. That particular track provides tremendous lift in the deep stuff, and allowed the sled to plane out very quickly.

If you're running any of the "Crossover" type tracks, or even a hard durometer paddle track, I expect you would see trenching issues with a 136" length.

 

[rab]

Thanks
first off the track is a 1.5 intense x 136

I will shorten up the front limiter and try to get the 18ish degrees and
I will then loosen the front coil spring nut till it just touches the spring and then mabey a 1/2 turn to ensure positive contact

Do think that I should try to remove the rear scissor stop to maximize weight transfer

how about the front scissor stop; the one that couples the front torque arm to the rear torque arm should I leave him there or remove him

The rear suspension main spring sag ;should I make it softer to get more tranfer

and set all clickers in the rear to softest and if she planes off I will set clickers harder untill the plane falls off or suspension becomes to hard and go back a couple clicks (just like jetting lean till burn down then go up one lol)

Make sense ?

 

[Scott]

Couple things....

Thanks
first off the track is a 1.5 intense x 136

I will shorten (Lengthen?) up the front limiter and try to get the 18ish degrees and
I will then loosen the front coil spring nut till it just touches the spring and then mabey a 1/2 turn to ensure positive contact

Do think that I should try to remove the rear scissor stop to maximize weight transfer? YES

how about the front scissor stop; the one that couples the front torque arm to the rear torque arm should I leave him there or remove him

The rear suspension main spring sag ;should I make it softer to get more tranfer

and set all clickers in the rear to softest and if she planes off I will set clickers harder untill the plane falls off or suspension becomes to hard and go back a couple clicks (just like jetting lean till burn down then go up one lol)

Make sense ?

 

[LRD]

Here is something else I discovered a few years ago which I wish I would have known close to twenty years ago when I started going to the mtns with Phazers. A high rate low rpm engagement primary spring. I tried a 130/290 in my revs a few years ago and the its reatest mod I have ever done for twenty bucks. A high rate spring is short with thick wire. The low preload lbs lets the sled just tractor off without trenching but anytime you blip the throttle snaps to full shift rpms. My buddy tried this style spring on his 07 doo 800r mtn sled that had that track everybody complained about for trenching and it fixed it. I went all the way down to a 100/260 with wifes sled with a 16-136-1.75 and she has never been stuck, makes for a lot more fun riding when you can set the wifes sled up like that. Takes a bit of experimenting to find optimum spring but its worth figuring out.

This style spring also makes it so easy to sidehill its amazing, when front starts to wash out downhill just blip throttle a little and track spins and washes downhill and front end either level or pointed back uphill, you control with your thumb!!!! This was the reason I originally tried this style spring. Friend who told me about it was for sidehilling reasons and he discovered it on a doo 600SDI, doesn't seem to matter what size engine. Mine was a extreme mod 395 lb 629 big bore rev fan and wifes was a stock 550 rev fan. Have also heard the 130/290 is working great on the new XP's with 146/154/and 163. Am now building a long track TNT and it will have this style spring in it.

Good Luck

 

[XC700116]

^^^ I'll second on the low enguagement spring. it makes it unbelievably easy to get un-stuck when you do get stuck and when in the real deep stuff on the flat it will get you moving without burrying yourself. especially since your not running a very big track on a pretty high HP sled.

 

[rab]

got the limiters shortened as per a holtz suspension install instruction that I came across

loosed the front track shock spring

Yes you are right I have toyed with Idea and know it from the wide

tracks/utility machines they are set up like that low engagement/higher rate

Have to re charge front shocks then out for the try

I am expecting positive results

I'll let you know

 

[shortstop20]

I agree on the low engagement. I run a 140/310 spring on my Pro-X 800. I have a steeper approach angle than my friend's because my sled started life as a short track. I am thinking about even trying a 130 lb. initial rate spring.

 

[rab]

Wow
I could not believe I was on the same sled what a huge improvement in deep snow driveability
I shortened the front limiter so the front torque arm travel is 5 to 6 inches
I put on 2 turns on the front track shock spring just enough to have a positive feel so it would not vibrate loose
put the rear suspension springs on the lowest setting
set all shock clickers to minimum

It goes through the the snow like there is no tomorow and planes off just like a boat
I can even accelerate in powder now

I think that my fuel consumption may also have gone down but I need to log more miles to verify that one

The only draw back to date is that I have lost a lot of bump absorption you can really feel them now all of them even that wash board stuff

But thats ok for the snow season when it all hardens up in the spring I will set it up like before for the better bump/suspension characteristics

So I would like to thank all for their input on this cause it has changed the sled night and day difference

The next thing is I am going to change the clutch spring as suggested ealier in this thread

Thanx again