Installed a carbon-carbon clutch in the 308

I absolutely fried the kevlar racing clutch I had in my supercharged 308 a while back. I decided to try a tilton triple-disc carbon-carbon clutch and finally got a chance to put it in. Here’s a few pic of what was required for the install. They told me that the pedal would be reasonably soft, but it is actually freakishly soft. I think the gas pedal is harder to push than the new clutch, it will be much nicer in traffic an the old one that was so stiff that my wife could not push it more than about ½ way down.

 

another

 

Here's the flywheel. I stuck with the stock flywheel and cut a pochet in it to accept the new clutch. The other option was a custom light weight unit, but I though the stock one would work out better for the street. The clutch is smaller and much lighter already, so it's basically in between stock and full race.

 

with the clutch on

 

The thoughout bearing required an adapter. I tack-welded it on just to be sure it stayed put.

 

The travel of the stock clutch is much more than the new one needed, so I made a new lever to correct the ratio so the pedal keeps the stock travel, but the throwout bearing moves the right amount for the new clutch.

 

I ended up having to add a little more clearance to the lever I made and lengthen the rod that couples it to the bellcrank. That's it. The only thing left is to find a softer spring for the pedal. Ferrari installed a spring up at the pedal that pulls the pedal down to keep it from bouncing and I guess to keep the throwout bearing touching the clutch. But with the revised ratio and lighter pressure plate, it pulls the pedal down almost 1/2 of the way..it's that soft now.

 

Peter,
It's a standard pressure plate, the part number is 6573HSORA-P12
the ORA part is the spring they just in the pressure plate, which I think is the softest one they make. The twin disc would have worked fine for the power I have (about 450-500 ft-lb torque), but would have needed one of the heaviest springs. The guy at tilton though I would be happier with this set-up. It's rated to 820 ft-lb torque, but the spec shett they send says they tested it to 1250...I guess that means I need to add NOS of something so I don't feel like I'm wasting it

Yes, I set the flywheel up to take the pot type clutch (P12 in the part#), so I machined a pocket that is .100" deep by 8.376" dia. Then I drilled and tapped it for 5/16-18 bolts. Tilon sets up their custom flywheels for though bolts, but since mine is a little over twice as thick as they use, I just tapped it which make instaling the clutch much easier. I used the 5/16 bolt because that is what they spec'd, had I thought about for even a second, I would have gone to M8 so I don't need different wrenches...


Jeff,
Thanks.....but I think if I do just one more think like this it's my wife who's going to beat me....and hard

Still loving the turbo....even if Allan thinks it's underpowered?

 

It's an Aeromotive fuel pump...I forget the model, A1000 maybe. My engine uses a LOT of fuel and I've got the pressure pumped up pretty high, I think it hits 80 psi at full boost. I've got an aeromotive filter too, it's not in the photo.

 

I bought it from summit racing acouple years ago, but I can't find the reciept...I'm pretty sure the current model is A1000. I guess it would fit somehow, it is about $300 and takes AN fittings, not included. . I only bought it because I needed the extra flow, the stock pump is good to at least 360 hp, probable more like 400.

 

sure. I don't know what I did with the originals, but since it's all apart anyway....
throw-out bering adapter and flywheel
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

Clutch....I haven't cleaned anything yet, so carbon dust everywhere. If you need more details about anything, let me know.

To save money and get a strong clutch, a quartermaster or tilton clutch pack can be installed on a modified stock flywheel the same way I installed this, I'm pretty sure. I would go with organic linings for the street or the carbon I have works pretty well on the street too, but it sure was pricey, very strong, but pricey. Quartermaster has a has some arangement with tilton last I heard, so both brand carbon clutches use the same technology.
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

Sure.

As far as how it works as a clutch, I like it. It will chatter if I’m not careful, particularly if it’s hot. Not bad, but not as smooth as stock either. The clutch pedal is very light and easy to work, think Honda civic. I guess about 6 or 8 people have driven the car, and none noticed anything odd or hard to work about the clutch. I can tell you the lighter pedal is much nicer than stock when I get stuck in traffic.

Performance wise, it handles the hp/touque I have easily. The trans shifts smooth and easy. It's much lighter weight than the stock clutch, but there was no noticable improment in acceleration, although I guess there must have beed an improvement....on most pavement it already will keep the tires spinning until the top of 3rd gear, so I'm traction limited until 4th gear, but I guess 4th must pull better...I didn't notice it though.