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FM1 Clutch Slipping

 
Old 01-22-2019, 08:00 AM
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Default FM1 Clutch Slipping

This morning, at 30F,, 5th gear, clutch started slipping. I've had this clutch in for about 4 years, 30K miles. I never did the push rod adjustment, as did not seem needed. I did change cylinders (master and slave) a few months ago.

Cold weather changing friction? Cold air yielding more torque? '99 Stock Rod engine, so I would think well within the limits of this clutch.

Experiences and suggestions?
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Old 01-22-2019, 08:54 AM
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Are you turbo charged? Cold weather makes many more boosts
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Old 01-22-2019, 09:42 AM
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Yes I am. Per my pulse width, I am likely about 5% more torque than typical, so about 220 - 230 ft-lbs. So, yes, up a little, but still should be within spec of this clutch, easily.
EBC is holding boost level pretty well (maybe 4 kPa over normal), so the 5% would be more air density related.

EDIT: Just remembered that last month, I replaced the bump stop on the pedal. Perhaps I should adjust position. Perhaps, go underneath the car and make sure the slave plunger is loose.

Last edited by DNMakinson; 01-22-2019 at 10:08 AM.
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Old 01-22-2019, 06:51 PM
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Update.

This afternoon I checked pedal play and there was some. It was 45*F, but still slipped, not just at 16 psi, but at about 10. So I took it back to waste gate of 7.5.
Looks like I'll have to pull the clutch and take a look.

Will be a couple of months, as I have surgery coming.

So, could it be possible that clutch is finished this quickly?

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Old 01-22-2019, 07:12 PM
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DNM I had a similar issue where at my same usual power level the FM1 clutch started slipping. I was at 14psi on a GT2560 so no way I was overpowering it. I adjusted the clutch several times to no avail. Ended up pulling it and posting a thread here to see if anyone saw issues with the disc and no one saw anything, check my thread history for details. I ended up swapping in a supermiata sport clutch puck and haven't looked back. I didn't bother trying to have FM look at the clutch or make it right because I was over it. I wonder if there is a manufacturing issues with these?
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Old 01-22-2019, 07:54 PM
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I never slipped my FM1 clutch at 16 PSI or those power levels. Not sure what would cause yours to slip... I did however slip a SPEC level 2 clutch at like 12psi. With a 2560.
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Old 01-23-2019, 12:18 AM
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How's your rear main seal?

Clutch may be fine, but if the seal starts leaking it wont be able to grab the now greased up friction plate etc.
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Old 01-23-2019, 06:45 AM
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My FM2 has suffered a Similar fate.
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Old 01-23-2019, 07:36 AM
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Originally Posted by hks_kansei View Post
How's your rear main seal?

Clutch may be fine, but if the seal starts leaking it wont be able to grab the now greased up friction plate etc.
New at time of change-out. No oil noticed at rear of engine (XMSN weep port) at oil change last week.
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Old 02-02-2019, 08:08 AM
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Ordered SuperMiata Organic Sport today, to have on hand when I pull the old one.
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Old 04-21-2019, 10:07 AM
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Strangely, after the car sitting for 2 weeks; I loaded 1.5.1, and inadvertently turned EBC back on. Much Boost, No Slipping.

I’ll take that for now.
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Old 04-21-2019, 07:44 PM
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Kinda sounds like the friction material was just glazed. I have seen 500 hp mustangs slip clutches and be fine after a few days of normal driving. My clutch has been through the ringer and back a few times and still holds solid, even with just loctite blue on flywheel bolts never been contaminated, but I haven't left it for years either.
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Old 04-21-2019, 08:38 PM
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My FM1 has been holding 230kpa from a 2560. I would highly recommend taking a couple minutes to adjust it exactly the way flyin miata instructs.
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Old 04-21-2019, 09:29 PM
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Fair Enough.
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Old 04-22-2019, 12:00 AM
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I run a Supermiata 4 Puck and couldnt be happier with it. Once you get used to the engagement of a puck clutch you will never look back. The FM1/2 clutches while decent are not as good as the Supermiata stuff IMO.
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Old 04-23-2019, 05:54 PM
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It's valuable to actually know how much torque your car makes under ideal conditions, i.e very cold and dry. Pretty normal for a car that makes say 230lbs SAE corrected on a 75 day to make only a little more on a cold day, corrected. Switch the correction off on the dyno plot and you might see some surprising numbers. Our BP organic is happy just below 300 lbs. If your car intermittently makes say 275lbs, you will be right at the rated limit (290lbs) of the system. That's too close in our opinion. If you call us, we would always recommend something with more headroom, the puck disc.

Once you are underway, there is virtually no difference between the organic and puck. The difference is simply a narrower and more abrupt initial engagement. That can easily be adjusted to then you have plenty of headroom to turn the boost up or do repeated hard auto-x launches, burnouts,. etc.
As it is, you will have to be careful on those magic, cold, high boost days. Where is the fun in that?
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Old 04-23-2019, 07:09 PM
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I understand the increased, uncorrected torque on cold days. And that may be the issue. That is why I mentioned it in the 1st post.

However, would the torque be more than what can be judged by the pulse width addition at the colder temperature? If that is the "little more" you refer to, then I don't think that is the sole issue. I have played with the SAE correction off and on in Virtual Dyno. If their math is correct, I don't think that would be enough to put me beyond the FM1 specs.

I guess we'll know more this winter. Meanwhile, I is happy. I have the Orange Organic in the basement for when it is needed.

I also appreciate the added fun on the magic days. Unfortunately, my winter tires then become the limiting factor at legal speeds.
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Old 04-23-2019, 09:18 PM
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Originally Posted by emilio700 View Post
It's valuable to actually know how much torque your car makes under ideal conditions, i.e very cold and dry. Pretty normal for a car that makes say 230lbs SAE corrected on a 75 day to make only a little more on a cold day, corrected. Switch the correction off on the dyno plot and you might see some surprising numbers. Our BP organic is happy just below 300 lbs. If your car intermittently makes say 275lbs, you will be right at the rated limit (290lbs) of the system. That's too close in our opinion. If you call us, we would always recommend something with more headroom, the puck disc.

Once you are underway, there is virtually no difference between the organic and puck. The difference is simply a narrower and more abrupt initial engagement. That can easily be adjusted to then you have plenty of headroom to turn the boost up or do repeated hard auto-x launches, burnouts,. etc.
As it is, you will have to be careful on those magic, cold, high boost days. Where is the fun in that?
I love the 4 puck, its been perfect for me. Im making 301ftlb at the wheels and the clutch has never even given a hint of slip. This might sound odd but I actually like the slight chatter you get when you take off from first gear, lets you know the clutch means biznass.
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Old 05-19-2019, 08:20 PM
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Update. I went through the hell of adjusting the clutch. Only change is now it starts engaging too high up for my liking.

Slippage still comes and goes. Will hope to open it next week. Orange PP, Organic Disk, ACT 13# Steel Flywheel going in. Will post pics of what comes out.

Is it possible my slave or master (nearly new) is somehow bad? Whenever I reach under the car, I can push the rod in at the slave, so the parts and adjustment seem good to me.

Also, no pedal feel different from when it wants to slip and when not.
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Old 05-19-2019, 08:32 PM
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I doubt the slipping issue is the hydraulic components, I replaced my slave and master with oem when my clutch was slipping and readjusted to spec with no difference.
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