TPI 911 Response Clutch Cover

Snowmow · Jan 29, 2018

Weight will matter no matter what! Doesn’t matter if it’s on the crank or the drive train. You guys that think weight attached to the crank is nothing.... hmmmm. Try attaching a 50lbs weight to the primary and see what that feels like on the pull start handle! Every bit counts!! Look at the flywheel affect of a old school oil well pump Jack! 900lbs of fly wheel running off a little 50hp Ajax engine firing about every 20 rev.

Max RPMS might eventually be reached. But Ain’t nobody got time for dat! And then to get that pig to rev down would require a separate brake on the primary.

sumtinwong · Jan 29, 2018

i would just like to add that all of this is just to the best of my knowledge! I am not collage educated and am not an engineer just a framer but i have ben playing with clutching for 20 years on all my sleds and all of by buddy's also. 90% of what i learned is from trial and error and reading! i have never hade the chance to run any of my philosophes by an engineer but i think its physics that mass = harder to spin = less spinning = less rpm i am sure some one on hear is laughing their a$$ off at my laminas explanation of what i THINK i understand

but like i said this is all just to the best of my understanding! and i just put nails in wood for a living.

Snowmow · Jan 29, 2018

sumtinwong said:
i would just like to add that all of this is just to the best of my knowledge! I am not collage educated and am not an engineer just a framer but i have ben playing with clutching for 20 years on all my sleds and all of by buddy's also. 90% of what i learned is from trial and error and reading! i have never hade the chance to run any of my philosophes by an engineer but i think its physics that mass = harder to spin = less spinning = less rpm i am sure some one on hear is laughing their a$$ off at my laminas explanation of what i THINK i understand but like i said this is all just to the best of my understanding! and i just put nails in wood for a living.

For Christ sake don’t be sorry. This is a good conversation... obviously no engineers have chimed in yet. And when they do. Say goodby to this tread making any actual real world sense at all. People with degrees gave us the 2012 proclimb clutching, and the doo rev and new doo 850 clutching.

Play darts blindfolded much?

That might help.

icr · Jan 29, 2018

http://patrickcustomcarbon.com/index.php?dispatch=products.view&product_id=29778

These guys claim no affect to max rpm with their lightweight cover

sumtinwong · Jan 29, 2018

I cant say different but i can tell you this ... every torbo company clams the best bang for the buck... every clutch maker clams the smoothest shifting and strongest pull...every pipe maker clams to be the best over all performance ... every powder track clams to trench less and push better... none claim to be over priced/harsh shifting/power draining/trenching monsters! but some times you just look at the advertising and its just that. i am not saying that it does increase the top rpms any "noticeable amount" by loosing 290 grams but im telling you it will only do just that by removing weight from that section and the fact that they tested and mentioned that {if you believe what they say} should be proof enough for you that it will do just that! it was a concern of theirs! like i stated above i don't know how much it takes to get a noticeable increase and it also depends on how far off the center of the clutch the majority of the weight was removed as to how much it effects it all but that's no reflection on the fact that it does and that link just backs the theory. are you starting to see it?

icr · Jan 29, 2018

No, I still think you’re wrong.

Snowmow · Jan 29, 2018

icr said:
No, I still think you’re wrong.

https://m.youtube.com/watch?v=DJUIs3yTHkU

sumtinwong · Jan 29, 2018

its ok all i have is my theory and small minded understanding of the more simple things.... im also sure that AK just experienced a out of this world fluke when those two buddies swapped caps and one tacked higher and the other tacked lower....and i am absolutely positive that when Patrick Custom Carbon Clutch covers were making that they hade piles and piles of money that they didn't know what to do with so they said lets do some pointless testing on something that absolutely wont and cant happen and make sure that we don't cause a over tack situation when we lighten the movable portion of the clutch and when they found that it didn't they figured they would bring this worthless info. to your attention to put your mind at ease about something that is imposable to happen and against all known laws of physics. rofl at the least i think i learned something to day!
and snowmow i laughed so hard i think a drop of pee came out!!!!

AKFULLTHROTTLE · Jan 30, 2018

Well I appreciate all thoughts but with that I dont need for someone to tell me what is happening is not happening. I have not tested any of this on a NA sled so maybe because of the lighter weight clutch cover paired with the hit of the boost it is allowed to spin at a faster rate and the clutching can not keep up until it is too late and the sled it hitting DET/over rev. I can also say with the slightly heavier IS cover I am able to run a bit less weight.

I have a customer in the states trying to run the same setup as me but with a clutch done by Patrick with carbon fiber cover and lightened up. We can not get him to run with the same weight as I, he is even slightly higher elevation.

I take back the NA statement as the one guy was able to pull the needed rpm the day he swapped but I was no there to see this.

Norway · Jan 30, 2018

Acceleration will be affected by clutch/crank/flywheel mass, not power output through CVT system, UNLESS as mentioned by LoudHandle your clutching is off somewhere causing loss of efficiency.

Spool time will of course be affected, as it takes more energy to spin heavy vs. light things. But once things gets up to speed, only frictional losses will slow it down.

If you remove mass from balancing, you should see a change depending on amount. Imbalance will vibrate/shake, consuming energy to shake your engine/chassis/bars etc. This energy is stolen from the force pushing on your pistons.
Power that shakes will not propel a vehicle =loss that can be remedied.

Anyone tried to start a sled without a clutch?

mt.sledder · Feb 1, 2018

I have been using the same 911 clutch cover that I bought from Duane back in 1999 on every one of my sleds since then. My last 7 sleds have been Silber Turbo rmk’s. The cover has been on 11 sleds and has to have at least 20,000 miles on it. The bushing is still in excellent shape. This season I added the adjustment ring to it in order to adjust the belt to sheave clearance without reshimming the spider. This makes it crazy easy to fine tune the clearance for butter smooth engagement. I found that I needed to blue loctite the adjustment ring. With the exception of cleaning my clutch after every trip the only other maintenance I’ve had to keep up with is changing weight bushings every 600 or so miles. The larger oilite cover bearing gives the clutch so much more stability and is near impossible to damage when assembling the clutch. I personally think it’s a great product and will easily buy another one if it ever fails.

sumtinwong · Feb 1, 2018

have you noticed any side effects from the sheave adjuster... higher engagements or changes in the bottom end pull?

mt.sledder · Feb 1, 2018

No adverse effects. Only moves the sheave in about 20 thou

sumtinwong · Feb 1, 2018

have you ever or do you need to rebalance the clutch after swapping the cover?

mt.sledder · Feb 2, 2018

I haven't ever had my clutch rebalanced after installing the cover. Not saying it wouldn't be a bad idea though, just a hassle to get a clutch balanced around here without having to send it down to a guy like Indy Dan which is international shipping. I'm sure if Dan did his balance job it would be no doubt be better. I just felt that if I was going to continue to use the cover on multiple sleds that having it balanced multiple times on new clutches it would be full of holes. I ran it on an 800 xcr full mod triple that ran between 9,500 to 10,000 rpm for 3 seasons without any issues.

sumtinwong · Feb 2, 2018

I think their is threaded holes under the cap for weighting and balancing the clutch.

BILTIT · Feb 2, 2018

There is and it comes with weights. I spoke to them and they say they arent really needed but some people like to use them.

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mt.sledder · Feb 2, 2018

My cover was one of the original ones anodized in red. It doesn't have the threaded holes for balancing like the new ones have.

sumtinwong · Feb 3, 2018

I jested wondered because my stock cover has drilled holes and I don't know if that's to balance the clutch or the cap but I am guessing its the clutch because I cant see Polaris balancing each individual part in the clutch.

icr · Feb 3, 2018

sumtinwong said:
I jested wondered because my stock cover has drilled holes and I don't know if that's to balance the clutch or the cap but I am guessing its the clutch because I cant see Polaris balancing each individual part in the clutch.

Your fixed sheave most likely has balancing holes as well

TPI 911 Response Clutch Cover

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