Aftermarket clutch cover reviews

kanedog

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Let me know any questions you guys have. We designed this cover to be stronger as our top priority. The towers and spyder in this clutch are not as stiff as they should be so we are trying to help them the best we can.
The stock curved shape is the strongest vs a circle or straight line from tower to tower, we have the analysis to prove that. Also in our experience, these style of billet clutch covers need to be 7075. 6061 does not hold up. We scrapped and warrantied $40,000 in covers back in 2014 learning that lesson so unfortunately we know from experience.
Our second priority was reduced rotation inertia, i.e. takes less energy to spin, which we were able to do by 11% vs stock. This is what you feel in throttle response vs how much lighter it is in grams.

Our cover provides .050 more clearance to the spyder nut. We split the difference vs stock to try to limit this interaction occurring but did not go all the way as we did not want the primary to over shift vs the secondary.
Great explanation. It sucks to have to overcome factory shortcomings. The .010” left for clearance would allow a small bit of flexing but not a full .060” of flexing. Longer lasting. I think the 911 allows full shift out but if any cover could withstand the flexing and remain ridgid, the 911 would be the design to have. All covers have different benefits so it’s all good.

Aside from the difference in bushings, which do you think is stronger? Zrp or 911 cover?
 
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Vern

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Speaking of sprung weight reduction of the clutch have you got any experience with removing the big weight ring on the primary?
I ran an m7 for years without the steel ring on the primary. That was a few years ago, so I don't remember if there was any drastic gains, but that sled was always a front runner in our group with multiple m7s. Didn't cause any issues though.
 

ZRP Engineering

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Speaking of sprung weight reduction of the clutch have you got any experience with removing the big weight ring on the primary?
From our understanding the big Cat performance shops and racers have all been removing it. We will not be making a recommendation one way or the other.
 

Coldfinger

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Sounds like cat still has the steel weight ring on the primary. My 10 has it. Must be a reason they put that heavy thing on because with all the pressure to make sleds lighter you think that would be the first to go. I believe it is called a harmonic balancer.
 

ullose272

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Sounds like cat still has the steel weight ring on the primary. My 10 has it. Must be a reason they put that heavy thing on because with all the pressure to make sleds lighter you think that would be the first to go. I believe it is called a harmonic balancer.
Was kind wondering about that too. Also a weight like that would help keep rpms up when it starts to bog down. Or at least that is my experience with cars and lightened flywheels

Sent from my Pixel 3 using Tapatalk
 

summ8rmk

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Indy dan makes a heavy cover for polaris.
He says their clutch is too light

Sent it
 

boondocker97

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Had a dealer at sea level tell me my high compression 900 would pull over easier if I put that ring back on there and wouldn't feel the "chugs" from each cylinder as bad. He might be right, but still not putting one on.
 

ndfb35

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A few shops have been mentioned, but who does the best work for the most reasonable price and in a timely manner?
 

boondocker97

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Anyone put some time on these this season and have noticeable benefits? My stock cover is starting to look a little worse for wear and considering a replacement.
 

CO 2.0

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I have the ZRP on both my sleds. Clutches run cooler. Run same rpms as before. I didnt get my clutches balanced but plan to once the season is over.
 
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