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850 E_TEC

Ski-doo#1

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He is right. Watch the video closely you can see it change the position of the ramp where the ramp pivots.

It won't change the weight but will change the distance the weight of the ramp is away from the clutch. This will change the centripetal forces within the clutch. Therefore, changing engagement. Also it changes the ramp angle so yes, it will change top engine RPM as well.

My question is if 300 engagement equals 300 top engine RPM?
 

Ski-doo#1

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GreatWhiteNorth
He is right. Watch the video closely you can see it change the position of the ramp where the ramp pivots.

It won't change the weight but will change the distance the weight of the ramp is away from the clutch. This will change the centripetal forces within the clutch. Therefore, changing engagement. Also it changes the ramp angle so yes, it will change top engine RPM as well.

My question is if 300 engagement equals 300 top engine RPM?

I don't think I'm correct on what I said.

I no longer believe engagement is affected by clicker change. The pDrive's clickers only change top engine RPM
 
D
Nov 27, 2013
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i asked the rotax guys about the new pdrive clutch. I thought you could only Change the engage rpm of the clutch by changing the Primary spring?! The said yes, but on the new clutch, as you can see it in the Video, you Change the whole Position of the ramps out and in and additionally the inclination.
So the wole rpm range moves up and down. If you cange the top rpm up or down, you also Change the engange rpm the same up and down......
Thats what the rotax guys told me......

here is the Video. look at time 3:18 and you can see the movement of the clicker.

https://www.youtube.com/watch?v=c1LoVKaC8Ds

The clickers on all skidoo's have always changed ramp position on every TRA clutch ever built .... There are 2 ways to change engagement either by changing primary spring or ramp profile or both .... Clicker position does not effect engagement.

DPG
 
D
Feb 12, 2016
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Weight of E-Start on 850

Don't mean to get off the subject, but does anybody know the added weight of E-Start on the 850's? Also is the only difference between a Summit X 850 and a Summit 850 SP the shocks & paint? It appears the running boards are the same? Thanks:face-icon-small-con
 
L
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Don't know the weight of the e-start, but the running boards are different between the X model and the SP model.
 

800Gader

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Clutch weight and oil use

Starter drives internally, so they saved weight not having a ring gear.
Also wondering how oil consumption can be less than before, when there is now gas back in the crankcase washing away oil. Or is the piston pin bearing lubed internally.
 

Dynamo^Joe

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it's not my thinking about the function. i asked the rotax engineers about the function of the new clutch, because i was really impressed of the new design.
But one of them told me, he is also a former snowcross racer here in Austria, that he is not satisfied with the new clickers because of the Change of the whole rpm range especially the Change of the Engagement......

this is only Information directly out of the rotax facility.......

Were you talking to Martin Krenn?

Anyhoo...looking forward to making cam arms for this bad boy as this will be "old hat" for me. Im excited fer shurr....
 
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mountainhorse

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Joe,

Coming from your vibration background... I'm sure the new 6-piece 'porkchop' crank is interesting for you.

With the 80mm stroke and no counter balance shaft, and going as light as possible.. wonder if the engine is 'buzzy' at all.

Wondering what the actual weight of the rotating assembly is (crank, flywheel, rods, pistons and clutch)... and how that weight compares to the 800E-TEC?





.
 

Dynamo^Joe

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Joe,

Coming from your vibration background... I'm sure the new 6-piece 'porkchop' crank is interesting for you.

With the 80mm stroke and no counter balance shaft, and going as light as possible.. wonder if the engine is 'buzzy' at all.
I suspect as the balancing is done by making the tolerance little to no room for variation - making everything weighing the same.
Pistons weigh the same
Con rods
..etc

Then have the crankshaft throws and theoretical 1/2 of the connecting rod weigh correctly in relation to the inertia of reciprocating weight at 7900 and its resonant frequencies - they'll have something that's smooooth as a sewing machine.

really, I just know enough to blow up. :face-icon-small-ton
 

rulonjj

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In relation to the rotational inertia, we see this engine will be making power around 7800 rpm vs the axys engine spinning around 8400 (depending on mods done to it). That's around 7% difference in rpm. Would the lower rpm make that much difference in the inertia? Or does weight make a bigger difference?
 
N

nuttyn01

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seriously!

Why don't you take your cloud of "doom and gloom" and go hang in the Cat section....they need some activity. I seriously can't get over the amount of negative commentary that comes from your keyboard.:spider:

Im curious to see how out of balance the new primary and 850 crank will be ... We will see in the fall if history holds true.

DPG
 

rulonjj

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Why don't you take your cloud of "doom and gloom" and go hang in the Cat section....they need some activity. I seriously can't get over the amount of negative commentary that comes from your keyboard.:spider:

Some people just hate to see others succeed and do good, wether it be a business or a person. This engine looks like it will be the engine to beat from here on out in the 2 stroke world.


With that being said I've got 2750 miles on my aerocharged Xm and the motor has never had an issue yet. I really doubt crank issues are all that common on the etec.
 

mountainhorse

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In relation to the rotational inertia, we see this engine will be making power around 7800 rpm vs the axys engine spinning around 8400 (depending on mods done to it). That's around 7% difference in rpm. Would the lower rpm make that much difference in the inertia? Or does weight make a bigger difference?

Both are significant.

The 70mm stroke 800 CFi has a feather weight crank in it... and 10mm less swing from the center than the 850-Rotax. That is also a very significant factor... mass and it's distance from the center.

There are indeed only 2 forged pieces on the new doo crank... but there are at least 4 other non-forged pieces of it... the bob-weights that are bolted onto the crank.

Until the consumer gets on the new G4 850 sled... not the pros/sponsored/factory riders... we won't know what plays out.

I'm interested in seeing what the rotating mass of the 850 Weighs all together... clutch with weights, crank, 2pc rods, pistons, bearings and flywheel/rotor. There has been weight trimmed off the engine in many areas of this new engine... much of it in the injectors and other areas..but is the rotating assembly itself actually lighter than the 800 E-TEC.

I've yet to hear if this engine and clutch is lighter or heavier than the previous 800 E-Tech. I see lighter components.... but no reference to actual weights of the engines themselves... point me in the right direction if you see it.

One other thing.... don't confuse responsiveness with inertia. A big stroke motor will have more grunt and "response off the line"... love the grunt of a big stroke engine... as a small rider... I don't like the "gyroscopic effects" that has on a given chassis in the past.

If the overall weight of the rotating assembly is, in fact, lighter... then that will be a HUGE leap ahead for Ski Doo with this 850 stroker! A torque monster without the negative aspects of a long-stroke motor. HUGE. If this is the case... there will be no compromise in nimbleness (ease of throwing the sled around on the mountain) of the chassis with the bigger stroke.

A 230lb rider will notice this less than a 180lb rider.

I'm confident that Doo and Rotax both did their homework on this engine... Looking fwd to throwing a leg over one to see first hand. :face-icon-small-ton


.
 
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D
Nov 27, 2013
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Why don't you take your cloud of "doom and gloom" and go hang in the Cat section....they need some activity. I seriously can't get over the amount of negative commentary that comes from your keyboard.:spider:

Why don't you go to Dootalk if you struggle with truth. On Dootalk they cuddle skidoo like a new born breast feeding.

DPG
 
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