I have more than 10Kmi on mine and I bought it used, I do think it is nearing the end of its useable life though. And what the hell do you care about the 10kmi lifespan you dont drive your FD more than 500 miles a year. You got a good 20 years before you would need to change the discs. This clutch is not at all suited for drag racing though. LOL

^LOL. The cerametallic is nice for drag racing though.

I am using carbon-r twin more than two years. Everything was perfect till the time i increase boost pressure and i passed 450Whp. Clutch started sliping from 3rd all the time, even after warm of the clutch.In general this clutch is very easy to use everywere, track/street but when you pass 450whp the problem begins. I tried compe-r disk and the skipping dissapeared!!! So for 350 to 440whp twin carbon is perfect. For more whp should use either the triple carbon or twin cerametalic!!!1

Machine shop has the pedestals. Im getting 6 made with 4mm off the top then I'll throw this bad boy on the 7 for testing. :)

ETA - a few months, I need to finish a few more projects.

so far the material used is from mcmastercarr

part# 8924K92 High-Strength 1045 medium carbon steel rod 7/8 diameter, 3 foot length.

Ill report as I go.

any outcome? I have here a car with this clutch. bought used at it start to slip at anything over 15 psi as we speak. When installing all of the plates looked very low on wear but offcourse did not measure the thickness. Drive ability and pedal feel is as good as stock in my opinion. when the box is off I will post the thickness of the parts.

I have been busy finishing the gb vm kits so now i can build my car.

I have everything to try this idea out with the shorter pedestals.

Ill know in a few months when I get the new engine in.

I forgot which plate wears faster, i think the back one so put the thicker plate in the back.

They actually recommend swapping plates like rotating tires to get more life out of it.

Probably less than the ideal clutch for street use longevity.

Seems like a lot of trouble to make shorter drive bosses I must say. Surface grinding the flywheel, intermediate plates and the drive bosses is what we've done here to rectify geometry at the top ring and remove hard spots. Even though the driven plates can be well within wear limits, these half metal/carbon clutches have their limitations, the twin plate here started slipping around 300kw Dyno Dynamics.

Pulled engine out.

Engine side plate is average 3.3 mm and gearbox side 3.6mm center steel plate is 5.4. (From 5.5 stock).

Seems in total 4.1-4.2mm wear.

Quite a lot lol. Pressure plate only had about 1mm clamping left with bolts out.

Ill remove 4mm from these hubs. If there ever need to be new discsc one can offcourse just add 4 precision

EDIT: after looking here it seems also new discs have this step near the tooth at the hub. there they are 5.5mm, if you measure the small step next to it seems stock thickness could have been ony 4.3mm. this would mean just 2mm needs taking of the hubs..
https://cimg7.ibsrv.net/gimg/www.rx7...eb0839bee.jpeg
https://cimg0.ibsrv.net/gimg/www.rx7...53528ef15.jpeg
https://cimg1.ibsrv.net/gimg/www.rx7...1d1c56fd3.jpeg

Don't know where I got the figures from, possibly Jesse Streeter in Japan, driven plate minimum thickness is 3.3 mm (new 4.2). Don't follow your wear figure there however, much less wear here on the carbon plates, the amount that needed to be removed for us on the drive bosses was around 1/2 mm.

Plates all have that step at the hub. That flywheel looks like it would require some love too!

It's a pity bits for these amount to buying a conventional clutch each time, but addition of an intermediate plate IM12, driven plate DP01, spline hub SH31 and drive boss kit DB01 would give you a triple plate more capable of holding some of the power put out nowadays.

Do you perhaps know how much free height the pressure plate has before being torqued down when laying on a new stack of everything? i could then just shorten te bosses to end up with that distance.

Like you, got the clutch used, so no joy there. I've approached Exedy locally in the past for any specs, but they never brought them into this country and didn't have a lot to share, other than saying the intermediate plate is common to other exedy multiplates and worth about $Aud250. Showing it to a specialist, the geometry of the diaphragm on the pivot ring was out when torqued down, or so he said, we got about 3 seasons out of it before upping the boost and finding it's limitation with a bit of wear added.

Here's the repair kit price from a couple years back, I think that's 5 plates in total plus various bolts. If you're not particularly wedded to the carbon plates, this mob I'm told, were doing cerametallic(?) sprung centre conversions for them, Clutch kits and clutch parts Australia | Clutch Repair Replacement Brisbane, and might have some information to share, possibly there's someone nearer you a bit cluey as well?
https://cimg9.ibsrv.net/gimg/www.rx7...f0ff4074e3.png

Took 2mm off them studs. Spring is flat again. Lets see how long it lasts.

It also looks like ideally there would a bearing with a smaller diameter fulcrum. Does anyone know if this is an option or available somewhere?

https://cimg7.ibsrv.net/gimg/www.rx7...5dc9f2ce6.jpeg