2011 p85 800 clutch weight?

[LoudHandle]

Updated for the verified TI Weight pin savings

From the hard parts alone you are correct. Below is how I arrived at my numbers.

I'm a slow typer, I was drafting my reply when all the additional TI bolt info was thrown in. My 1 1/4# was just the difference in his Weight verses my stock weight.

. 4294 Grams for stock clutch with spring and 66 Gram weights
- 6 Grams for the difference between his 64 Gram weights and my 66's
- 3732 Grams his clutch weight after PCC balancing / servicing and hard part install
= 556 Grams of weight saved with PCC CF cover, TI cover bolts, TI weight pins, and balancing / truing sheaves. 556 Grams = 1.23 #'s

. 280 Grams PCC claimed savings with their CF cover and TI bolts
+ 19 Grams Verified savings with their TI weight pins
+ 101 Grams PCC claimed savings with their TI Clutch bolt
for a total of 400Grams (which = 0.882 #'s) Saved with PCC hard parts

But only the CF cover, cover bolts, and TI pins were included in his clutch weight. So

I'm left to assume the other 299 Grams (0.658 #'s) is the aluminum removed from the clutch itself to true the sheaves and balance the clutch. Or about a Cubic Cetimeter of aluminum, (a cube just over 10.2 mm (0.4") per side).

. 556 Grams saved After PCC's hard parts and servicing
+ 101 Grams saved with the TI clutch bolt
= 657 Grams Saved = 1.45 #'s saved

If one adds the new lite weight crank to that it becomes 3.95#'s of less rotating mass.

I once built a Polaris triple with TI connecting rods and was able to remove 3#'s from the crank to rebalance it. Believe me it make a huge difference in the acceleration and throttle response of the engine!

While the 19 Gram difference did not change the volume of aluminum removed substantially, I updated my post just the same.

 

[Kcjepperson]

Looks like there are some funky avatar things happening, or it is just me?

 

[BILTIT]

I don't see any avatars.

I am on my phone though.

 

[ZRP Engineering]

280 Grams PCC claimed savings with their CF cover and TI bolts
+ 19 Grams Verified savings with their TI weight pins
+ 101 Grams PCC claimed savings with their TI Clutch bolt
for a total of 400Grams (which = 0.882 #'s) Saved with PCC hard parts

But only the CF cover, cover bolts, and TI pins were included in his clutch weight. So

I'm left to assume the other 299 Grams (0.658 #'s) is the aluminum removed from the clutch itself to true the sheaves and balance the clutch. Or about a Cubic Cetimeter of aluminum, (a cube just over 10.2 mm (0.4") per side).

I think it should 380g from the cover since he has an 800, so that would be 199g unaccounted for.

I think 199g is just too much material to come from balancing and machining

 

[BILTIT]

I don't have any pics but if you saw it you would understand how much material is removed.

The back side outer edge of the stationary sheave is cut ~1/3? Into the previous balancing holes.

Supposedly it is much easier to balance with this weight removed since so much is taken off the other end.

 

[BILTIT]

I will try and take a pic next time I am out there.

 

[BILTIT]

Kcjepperson - do you think the cause of blowing through the secondary spring was more from the lighter primary or the extra punch of the 910?

 

[LPIdaho]

I don't have any pics but if you saw it you would understand how much material is removed.

The back side outer edge of the stationary sheave is cut ~1/3? Into the previous balancing holes.

Supposedly it is much easier to balance with this weight removed since so much is taken off the other end.

If there's really that much weight taken out from balancing then I'd definitely send my clutch out to him.

 

[ak]

I don't have any pics but if you saw it you would understand how much material is removed.

The back side outer edge of the stationary sheave is cut ~1/3? Into the previous balancing holes.

Supposedly it is much easier to balance with this weight removed since so much is taken off the other end.

Maybe I missed it but who balanced your clutch? PCC?

 

[BILTIT]

Yes PCC.

 

[Kcjepperson]

I am sure it's a little of both. I am running a 180-260 spring. I wish I could get the final rate a little lower. More like a 180-240/250 ish. I tried the gold/black spring I think it's a 170-240 and was still just a little to quick on the upshift

 

[BILTIT]

Interesting, I will have to keep this in mind for my 2004 pro-xr which is getting a 910 right now.

Currently I run the red/black spring, with my only run on it and the first run of the year (can be very decieving) it did seem to lack some midrange punch. I also geared down a little with drivers so things feel different for many reasons.

 

[BILTIT]

Here is a few pics of the material removed on the backside.

 

[LoudHandle]

Ouch!

I may get the CF covers from him at some point, But with workmanship like that, he will not be balancing my clutches, even if it is included in the price of the cover. That (IMO) is a very poor way to do it. Not at all what I thought you were describing, from your narrative. I hope it does not flex enough where he lightened the stationary sheave to frag on you. It looks pretty weak there now to me.

I pictured him thinning the webs and leaving the rim alone for hoop strength. Lightening holes in either the axial or rotational planes would retain much more strength and not blatantly sacrifice hoop strength.

For a guy that has spent most of his life around racing, he should know better.

Sorry I'm so opinionated, hope she holds together for you!

 

[ak]

My clutch is at Carl's cycle right now being balanced, I also run the carbon fiber cover so when it returns I will take a pictures of how it turns out.

 

[ak]

I recieved my clutch back and it looks like they balanced the fixed half just like the factory does, but for balancing the carbon cover they added washers to the bolts that hold the cover, to balance the clutch.

Also it weighs 8.53 lbs (that's without the primary bolt and spacer) running 66 gram weights (that's what I run for sea level).

 

[BILTIT]

Ouch!

I may get the CF covers from him at some point, But with workmanship like that, he will not be balancing my clutches, even if it is included in the price of the cover. That (IMO) is a very poor way to do it. Not at all what I thought you were describing, from your narrative. I hope it does not flex enough where he lightened the stationary sheave to frag on you. It looks pretty weak there now to me.

I pictured him thinning the webs and leaving the rim alone for hoop strength. Lightening holes in either the axial or rotational planes would retain much more strength and not blatantly sacrifice hoop strength.

For a guy that has spent most of his life around racing, he should know better.

Sorry I'm so opinionated, hope she hold together for you!

He will be the first to know if it doesnt hold up!!

 

[kanedog]

When I first looked at your clutch I almost crapped my bed!!!!
With those semi circles cut out of the edge it now weakens and takes away from the strength of outer edge of the clutch. It gives the metal a great place to start to crack and when it happens, it happens fast and then boom! 8200 rpm of clutches shooting out in any of 360 directions it dam well pleases. Drilling small holes is different as both edges are intact and still hold strength.
Picture your clutch spinning at 8200 rpm and the clutch fully shifted out, squeezing the belt like a mofo on the top outer edge of the sheave. That inch or two of hacked edge will start to crack and clutch will come apart. It's just crappy aluminum.
A risk of bodily injury is possible as well as damage to the machine. Belly pan, belt and secondary, clutch guard and some electronics could be damaged.
That right there is scary as heck.
Dude destroyed the structural integrity of that sheave. Its kinda like taking half of the width out of a flat roof truss in just one spot. Any engineer would crap his pants.
I would not run that clutch. Accident waiting to happen. IMO.
If someone tells you it's ok to run that the way it is, offer to trade them on the spot for their clutch if it's so great. Betcha there will be no trading of clutches.
I gotta look at that pic again......whoa

 

[carbontj]

When we lighten the primary clutch we take .250 off the fixed sheave outer balancing ring, thats what it is there for balancing. Once we do that the clutch balances out better on that sheave, do to the impurities in the casting, we true it up. Yes I have been around racing my whole life and maybe have seen things other people don't get a chance to see and I am bringing that to snowmobiles. If you have ever seen a sno cross clutch that has been lightened you would think what I do is VERY tame, they are paper thin (actually cutting the sheaves) in all areas and holes in webs, towers totally lightened. Ovals sleds are just then same and they turn 10,500 RPM for miles at a time (they don't need to lift for the corners very much) with no issues. I understand people don't like change and when someone changes there ideas it is hard for them to understand or comprehend. If Derek's clutch blows up I will replace it no questions. I am not afraid of changes, thats what makes what I do fun, stretching the envelope...

I actually can take over 300 grams off the secondary, I have about 5 out there this year for testing to make sure there are no issues, I do have people test my stuff before I offer it out to everyone.

Manufactures testing for all parts (clutches, drive line, to ski's) are very very stringent and to be honest over kill from a performance stand point.. I have been prievie to that information as they (Polaris) have tested my covers in numerous ways (inertia, endurance) and all tests have been better in all aspects. I could go into more detail if needed..

We spin balance our clutches not static balance. we spin at 1500 rpm. All done with infra red lasers, it is a crank balancing machine I converted with a arbor for snowmobile clutches.. I actually took the balancer to Atlanta to the manufacture and had him verify and set up...Then getting up to speed with all the new touch screen options. They are actually on line with me/machine if I have any issues or questions..How do you like your car or truck tires balanced static or spun?

TJ

 

[BILTIT]

Thank you for posting and giving us some insight, appreciated.