Ski-Doo pDrive clutch how ramps work Part 1 iBackshift

How pdrive ramps work with a detailed, hopefully simplified explanation(s) that won't make you fall asleep. I'll show what I learned of the difference in ramp positions defining "more aggressive" or "less aggressive", how a different ramp shape will get the primary engine clutch to push differently on the drive belt.
The Ski-Doo pDrive primary clutch is without a doubt, one of the greatest and most enjoyable “to tune” snowmobile CVT inventions. But how does the "ramp" or "cam arm" whichever you want to call it, work? Different ramp geometry controls how the ramp will push. Once you learn how these ramps work, then you can apply that knowledge, optimizing a ramp, achieving your objective for any category of sledding you do.
This video is the start, more pDrive tuning videos will follow.
You have a tuning question; ask in the comments.
Thanks for watching
www.ibackshift.com/

[@mikecarney6141]

Love the simulated wood paneling you put up!!

[@curtisbuhs306]

Good to see the differences explained.

[@fxnytroxtxFPP]

Thanks for explaining 👍

[@AdventureStreamingGuys]

Great info Joe...thanks

[@robschafer2723]

Nice job!

[@nonipaulette4520]

right on!

[@kwmiked]

So what do u think about the BMP double adj ramp? They use magnets like in they're Polaris weights and they changed the clicker also. Think its necessary? Skidoo has a bunch of ramps along with other companies, I really don't see the need for magnets to add thru the heel to tip since the clicker tec makes it steeper 🤷‍♂️🤔

[@iBackshift]

they are "tuner" weights. IF you want to tune, THEN buy a set of tuner weights. In the end just like most use of tuner weights - you'll end up fiddling with them a handful of times, THEN, you'll get tired of it and leave it alone and just drive. Your friends too, will get tired of YOU tuning your setup every time you take a break.

[@troyroquette261]

👍

[@rolly79]

grate show like it ,,,,skidoo 2016 600 rs dragrace 500 feet ideal ramps ? and rmp

[@iBackshift]

The stock ramps are great. Where you are going to get off the line the hardest is to have the engagement speed as close to 6000 as possible, then choose your helix start angle, somewhere in the 70 degree start for .31.

[@rolly79]

@@iBackshift just afraid it would spin out im running 46-44 now and bearly staing put in the starting matt. My engagment rmp is 5800 .would a 70 launch harder ? In theory when in starting from a startmat the prlmary wont pull all that helx angle at 5800 r Mp actually does it soften up the launch?

[@kwmiked]

Think slp had a magnet setup also, im gonna have to look again. This sucks having a skidoo and a Polaris when im use to the Poo set ups

[@iBackshift]

What is the most simple ramp (cam arm) you can use? Then get that simple use cam arm, OR just tune the stock ramp with the pivot bolt (pdrive) and tune with springs.

[@minnesotasnowmobiler.racer5513]

the backcountry has the 990 ramp and a mxz has the 968. if your at sea level riding how would the mxz clutching work in the backcountry? would that be an improvement in drag racing than the backcountry clutching? cant imagine with the low gearing of the backcountry that any clutching would not back shift fast enough.

[@minnesotasnowmobiler.racer5513]

would be fun to run install mxz clutching into the back country and see how it goes. right now the back country is very revvy and backshifts so fast it is almost like an atv engine braking.

[@iBackshift]

@@minnesotasnowmobiler.racer5513 The 968 and the 990 are the EXACT same profile. Just the weight(mass) is different.

[@mastershefu147]

Can I get higher rpm engagement then 4000?

[@iBackshift]

Look at the primary clutch spring forces. What is the start force? Increase the start force. So if like have a 120/350 then go 150/350, raise the start force, raises the engagement speed.