Clutch and flywheel question
Rochester, I'm iffy on the CMAK. I think the HD CSC would be adequate as long as you aren't seriously increasing clamping force to copper-puck racing levels.
Rethinking my question re: noise above. We used solid unsprung 4-puck copper friction disks, with uprated pressure plates, for the RX7 race cars. They chattered when cold - it was the friction disk stick/unsticking to to the flywheel and pressure plate - but once the car was warmed up they didn't. Clutch engagement was brutal though.
For milder race cars (IT, where the car is mostly stock) we used stock friction disks and an uprated pressure plate (from a B2500 pickup IIRC). They tolerated more shiftor error.
So unless anyone chimes in with it causes damage by doing X, I think this is like the weird blow-off sound you get with HFCs when decelerating - it's a thing, but not that important.
Rethinking my question re: noise above. We used solid unsprung 4-puck copper friction disks, with uprated pressure plates, for the RX7 race cars. They chattered when cold - it was the friction disk stick/unsticking to to the flywheel and pressure plate - but once the car was warmed up they didn't. Clutch engagement was brutal though.
For milder race cars (IT, where the car is mostly stock) we used stock friction disks and an uprated pressure plate (from a B2500 pickup IIRC). They tolerated more shiftor error.
So unless anyone chimes in with it causes damage by doing X, I think this is like the weird blow-off sound you get with HFCs when decelerating - it's a thing, but not that important.
Thread Starter
Joined: Feb 2017
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From: Charleston
I think the point is that the oem CSC is weak sauce. They make more robust CSCs - that is what the HD kit is. Then again, you'll have the trans out anyway so why not. If you're dropping $1500 on a clutch a few hundred more isn't that big a deal, right?
I am imagining this conversation with my wife and it doesn't go well. For some reason she doesn't trust me to repair the car without (to her) needless upgrades...
I am imagining this conversation with my wife and it doesn't go well. For some reason she doesn't trust me to repair the car without (to her) needless upgrades...
Thread Starter
Joined: Feb 2017
Posts: 2,952
Likes: 598
From: Charleston
Also - yeah, I'm super gentle on the clutch. I don't want to have it fail (I think I just hit 60k miles) and have the damn towtruck driver tear off my front lip to get it home. I've had fails before on standard clutch-fork setups where the slave cyl fails and it will ruin your day.
Registered Member
Joined: Dec 2019
Posts: 763
Likes: 362
From: Chicago, IL
Mike, have you ever had your CSC fail on you while driving? It's pretty unnerving. The kind of thing you never forget.
Granted, it's been 6 years later, and the RJM pedal claims to mitigate the underlying design flaw... but still, I think about it in some way every time I drive the car.
Granted, it's been 6 years later, and the RJM pedal claims to mitigate the underlying design flaw... but still, I think about it in some way every time I drive the car.
Thanks for reminding me to order the RJM clutch pedal, really looking forward to that upgrade.
Thread Starter
Joined: Feb 2017
Posts: 2,952
Likes: 598
From: Charleston
I think a lightweight flywheel is in my future. I might add some Shockproof to the transmission to cut noise, but you can't go full shockproof or the syncros won't work - they need *some* friction. I'd use a sprung hub street disc and mild pressure plate.
I'm still thinking a beefier all-metal CSC is the way to go. Throwout bearings on clutch fork designs can still go bad and ruin your day - that's what killed my RX8. Throwout seized on the trans shaft, it and the fork bent the crap out of each other, and then it jammed into the clutch fingers. Steady driving on the highway at about 60 to seized drivetrain and frags that cracked the bellhousing. Had to beat it apart with a wood-splitting wedge when we got engine and trans out of the car, and the trans input shaft was toast.
How soon? Anybody's guess. Hell I bought an RJM pedal last year (!) and haven't installed it yet.
I'm still thinking a beefier all-metal CSC is the way to go. Throwout bearings on clutch fork designs can still go bad and ruin your day - that's what killed my RX8. Throwout seized on the trans shaft, it and the fork bent the crap out of each other, and then it jammed into the clutch fingers. Steady driving on the highway at about 60 to seized drivetrain and frags that cracked the bellhousing. Had to beat it apart with a wood-splitting wedge when we got engine and trans out of the car, and the trans input shaft was toast.
How soon? Anybody's guess. Hell I bought an RJM pedal last year (!) and haven't installed it yet.
Yeah, me too. Still targeting a tune for 2021, so Clutch/FW would be a 2022 mod with parts purchased on Black Friday this time next year.
Low miles, long plans. Not quite as long as your pedal, however...
WTF, man? 
Slacker.
Low miles, long plans. Not quite as long as your pedal, however...
Slacker.
Thread Starter
Joined: Feb 2017
Posts: 2,952
Likes: 598
From: Charleston
I think since I bought the car May 2018 I've had a total of about 20 hours to work on it. Most of those were over Christmas 2019, installing the full exhaust and incurring the wrath of my wife. I just don't get a lot of free time, and when I do I'm already exhausted from other life stuff. I ain't 20 any more. Or 30. Or 40s for much longer.
The RJM pedal looks like install will take 30 minutes and getting adjusted will take the rest of a 3-day weekend. I just haven't had that amount of time to dedicate to having the car off the road.
The RJM pedal looks like install will take 30 minutes and getting adjusted will take the rest of a 3-day weekend. I just haven't had that amount of time to dedicate to having the car off the road.
I think since I bought the car May 2018 I've had a total of about 20 hours to work on it. Most of those were over Christmas 2019, installing the full exhaust and incurring the wrath of my wife. I just don't get a lot of free time, and when I do I'm already exhausted from other life stuff. I ain't 20 any more. Or 30. Or 40s for much longer.
The RJM pedal looks like install will take 30 minutes and getting adjusted will take the rest of a 3-day weekend. I just haven't had that amount of time to dedicate to having the car off the road.
The RJM pedal looks like install will take 30 minutes and getting adjusted will take the rest of a 3-day weekend. I just haven't had that amount of time to dedicate to having the car off the road.
Thread Starter
Joined: Feb 2017
Posts: 2,952
Likes: 598
From: Charleston
Thanks - I'll check it out. The RJM instructions are actually pretty decent - I've read through them a few times - and removing/replacing the stock clutch pedal assembly doesn't seem too difficult. I did a similar thing in my RX8 after the clutch pedal spot welds snapped (Black Halo Racing Pedal) but that didn't require any adjustment other than the pushrod.
Registered Member
Joined: Apr 2019
Posts: 6
Likes: 7
From: Austin, Texas
I have a JWT lightweight flywheel in my car with a stock style Z1 clutch kit and honestly it doesn't chatter much at all. Only noticeable sound is when you are stopped in neutral without the clutch pressed in(it kinda sounds like a diesel or a tractor then). I also have the stock pedal assembly and a Z1 CSC elimination kit. Drivability remains the same, but with the revs rising and falling much faster!
Registered Member
Joined: Dec 2019
Posts: 763
Likes: 362
From: Chicago, IL
Sorry just seeing this now. I didn't get it but I think about it every now and then. I'll eventually cave in and spend the $300 for it. I'm used to the clutch feel however I know it could be better.
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