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Discussion Starter #1
I've been having a problem with clutches exploding or failing on me. The friction material is fine, but it's everything else that fails.

I've had three clutches in the past year:
1. Competition Clutch Stage 4, (8037-1620) - Clutch spring retainer failed, spring lodged in clutch.
2. Competition Clutch Stage 4, (8037-1620) - Clutch spring retainer failed, spring shattered, but clutch was still usable.
3. Clutch Masters FX500 (8036-HRB6) - Clutch hub splines sheared off, clutch just spun on the input shaft.

Any suggestions that can handle the power? People keep saying twin-disc, but it's not the friction material or slippage, it's the components outside of that..
 

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Arouse the DAMPFHAMMER!
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Hello AngryScotsmann,

this is an interesting issue and looks primarly like a torsional vibration issue, less like an clutch system. To follow that first impression following questions I would like to be answered:
  1. What intake setup do you have?
  2. Do you have EGT's to validate the combustion of your engine cylinders individually?
  3. What kind of torsional damper do you use in this engine setup?
  4. Do you have an option to use a oscilloscope to check the engine speed signal?
  5. Did you mass balance the crank drive?
  6. Do you run any faster gear shift mechanism?
Markus
 

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Discussion Starter #3
this is an interesting issue and looks primarly like a torsional vibration issue, less like an clutch system.
Why do you think torsional vibration would cause clutch hub springs to fail? There are other Honda drivetrains more rigidly mounted than my setup.

To follow that first impression following questions I would like to be answered:
  1. What intake setup do you have?
  2. Do you have EGT's to validate the combustion of your engine cylinders individually?
  3. What kind of torsional damper do you use in this engine setup?
  4. Do you have an option to use a oscilloscope to check the engine speed signal?
  5. Did you mass balance the crank drive?
  6. Do you run any faster gear shift mechanism?
Not sure how any of this is related to the original question, but:
1. RBC
2. Don't know.
3. None.Just four rubber mounts holding the drivetrain in place
4. Do you mean to verify the RPMs? No and not sure what this would accomplish.
5. Do you mean balanced the crankshaft? Yes.
6. Yes. I have a sequential gearbox with flatshift. The clutches do not fail on shifts, but on throttle transitions.
 

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Arouse the DAMPFHAMMER!
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5,758 Posts
Why do you think torsional vibration would cause clutch hub springs to fail? There are other Honda drivetrains more rigidly mounted than my setup.
I talk about torsional vibration from the drivetrain-clutch-crank system. 1st, it's a design rule for clutches, that the maximum spec'd torque is a fraction of what the parts of the clutch can hold. And 2nd the torque which lead to slip the friction plate is much lower what all other parts can stand. Your engine can't produce a sheared shaft hub spline. You need dynamic forces or torque events, like a quick shift where peak torque is many times higher than what the engine is presenting, just because the hard torque step introduce an oscillation in the system, which can resonate and factorize the torque at the clutch-shaft-...system. The basis is Newton 1st, 2nd and 3rd law of motion...as an hint.

...The clutches do not fail on shifts, but on throttle transitions.
An assumption. What if the shift event shear the spring bracket by hard oscillation introduced by the torque and shaft speed step...like a Dirac step? To give you an measured and understood example. When a 6 ton generator is rotational accelerated by an 3600 hp engine from 0-1500 rpm, the torsional oscillation at the clutch leads to 2 times higher peak torque spikes as at WOT on zero load! I experienced multiple clutch brakes exactly because of that at customer plant sites.
 
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