FM1 Clutch Slipping
#1
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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?
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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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.
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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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?
DNM
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?
DNM
#5
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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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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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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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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?
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?
![wink](https://www.miataturbo.net/images/smilies/wink.gif)
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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.
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.
#18
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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?![wink](https://www.miataturbo.net/images/smilies/wink.gif)
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?
![wink](https://www.miataturbo.net/images/smilies/wink.gif)
#19
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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.
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.