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FM1 Clutch Slipping

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Old 05-20-2019, 08:52 AM
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If it wasn't properly adjusted exactly like the instructions state when you installed it and you have driven it 30,000 boosted miles you have more than likely worn the disk beyond it's service limit.

It's a PITA but it's necessary to make that clutch setup live.
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Old 05-20-2019, 09:06 AM
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OK. Looking for advice then. @emilio700 when I put SM clutch in, should I leave the extra travel, AKA FM adjustment, or
return to stock adjustment? Or base decision on making sure I have free pedal and plunger(s) at top, and full disengagement at bottom.
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Old 05-20-2019, 09:17 AM
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Originally Posted by TNTUBA
If it wasn't properly adjusted exactly like the instructions state when you installed it and you have driven it 30,000 boosted miles you have more than likely worn the disk beyond it's service limit.

It's a PITA but it's necessary to make that clutch setup live.
TBH, this does not make sense to me. for instance, this does make sense It seems to me, that as long as I am getting full dis-engagement, as ID'd by easy shifting into First or Reverse when stationary, engine running; and both rods (master and slave) are free when pedal is at top stop; that the clutch is being treated correctly. What am I missing?

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Old 05-20-2019, 09:27 AM
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You're not. That's correct adjustment.
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Old 05-20-2019, 11:27 AM
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Originally Posted by TNTUBA
If it wasn't properly adjusted exactly like the instructions state when you installed it and you have driven it 30,000 boosted miles you have more than likely worn the disk beyond it's service limit.

It's a PITA but it's necessary to make that clutch setup live.
As long as the clutch is adjusted to where the TOB is not constantly engaged then no clutch should wear prematurely. The FM clutch is no different than any other, make sure the TOB isnt engaged and adjust for a little freeplay and youre good.
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Old 05-20-2019, 11:36 AM
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Yep. The only difference being that it somewhat often seems to require adjustment that falls outside what the factory allows, hence directions to remove the stopper if necessary. Which is... something i've never seen on another clutch, ever.
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Old 05-20-2019, 11:37 AM
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If you are starting with pedals that have OEM adjustment, you should not have to make any adjustments for any OEM style replacement clutch.
As others pointed out here, as long as there is some free play in the pushrod when the pedal is released your clutch should work perfectly. If it is slipping it is because the disk is either worn or contaminated. The other possibility is the diaphragm springs are worn out. This condition is quite a bit more rare but it can happen with diaphragm springs that are not heat treated.

We have only had a handful of reports of customers slipping their supermiata sport clutch within it's torque rating. In each case it was a leaking rear main seal.

With an oem style pressure plate we recommend sticking with the OEM pedal adjustments. With our race twin-clutch both of those adjustments can be fiddled with to radically shorten the total pedal stroke which makes shifting faster. Don't try to replicate the short pedal stroke with an oem style clutch though.
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Old 05-20-2019, 05:51 PM
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I'm on FM1 for more than 30000km and i'm now nearing torque limit and still didn't manage to slipp it. Only time i slipped it, was on track doing north 18 psi and after i had adjusted the pedal to have the clutch to grab in the upper zone. Got out, adjusted it to previous position and never happened again.

Originally Posted by emilio700
With our race twin-clutch both of those adjustments can be fiddled with to radically shorten the total pedal stroke which makes shifting faster. Don't try to replicate the short pedal stroke with an oem style clutch though.
Could you share data on shifting times? I'm usualy in the 0,25s zone, FM1 clutch and stock shifter.
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Old 05-20-2019, 05:55 PM
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Originally Posted by kamel6k
Could you share data on shifting times? I'm usualy in the 0,25s zone, FM1 clutch and stock shifter.
Limited by syncros. Fastest we ever saw in data, ~80ms during protoyype testing on the first race Twin back in 2008. But that isn't something we ever spend any time monitoring.
Pushing shifts that fast will eventually destroy your syncros even with a 5.5" Tilton. That's what dog boxes are for.
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Old 05-20-2019, 06:19 PM
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You made me check my track logs. Although i always had the impression my shift times were better on track, i had never measured it before. I guess spending some hour's driving, improve my shift times alot:



Even better if i ignore TPS.

Thanks for the data.
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Old 07-16-2019, 06:51 AM
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SuperMiata Sport clutch in.

Old FM1 was not to rivets, but it was worn. Hot spots on flywheel and PP. I was leaking oil from the head port, but it was all over the case, not on the clutch plate.

SM is nice. Engages quickly. Also put in ACT 13 lb "Street Light" flywheel. Am breaking it in this week (s) to be ready for MBTG and MATG.

Re-adjusted clutch to normal travel, which is much to be preferred, but now I am having to re-learn. And, man, is that a tough little job. So tight, even after un-bolting the ECU. Even attaching the switch harness is hard.

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