I need racing clutch suggestions

[Tommy]

I took my E-M to an open track event today and burned up the second clutch in the past six months. The engine is a 351 Windsor (about 400 HP). The transmission is a Richmond 5 speed on a Lakewood bell housing with hydraulic actuation. I have 87 Corvette suspension with Hoosier racing tires (315R35 17), so I have very good traction. After the first (stock) clutch failed, I replaced it with a Centerforce Dual Friction unit. Apparently that was not up to the task, so I'm looking for the next step up. What can you guys suggest as a good racing clutch for track events? I'm particularly interested in hearing from people with actual experience with them. Thanks.

[Ant]

Do you mean road race or events with a lot of drag take offs?

I raced for four years with a beefed up pressure plate and sawblade with bonded/riveted linings, as the clutches with the marcel in between the plate and lining are rubbish for competition, and had no problems in 400bhp L34 Holden Torana (Bathurst model.) I am easy on clutches not into dropping them, and once your racing the idea is smooth and fast!

Maybe you should contact an outfit that specialises in setting up clutches as to avoid going to triple plate Tiltons or AP race stuff, which solves the problem, but has some downfalls regarding stop starting in heavy traffic, I would go for a minimum 2500lbs pressure plate and then maybe a kevlar or good quality material solid disc driven plate around 10.5" - 11" diameter.

Having had no experience with kevlar linings, they seem to be the way to go, you may have had kevlar and sintered bronze or whatever with your dual lining?

The bottom line is find a good clutch maker; Mcleod have been good to me with their simple single plate systems, or if you do a lot of track go for the multiplate Tilton or AP, as far as I know you will pay about the same price for either!

My 3c worth - Ant

[Tommy]

Additional info:
I think I cooked the first clutch by feathering it during launches at the autocross. Because of that, I took it easy with launches on the second clutch. I heard it fail initially while accelerating at full throttle in 4th gear (I heard the RPMs suddenly rise).

[cobrashoch]

Your problem is a common one that we could talk for hours about.
1st thing, a centerforce is not a very good clutch for racing because by their own design admissions they are heavier (shift harder) at higher RPM's. I have heard that with them, you can switch the disk to a stock disk and the service is much better to. But 400 horspower is about the max for them in any rate, and there is also the school of thought that the disc should be the wear component because it is the cheapest link in the chain too.
Before I switched to a auto I used a Hayes #39-608 long style Pro clutch. It is a 12 bolt pressure plate as apposed to the common 6 bolt mounting system and of course requires its own fly wheel with 12 bolt holes.
Point is, I didn't JUST get there with that setup. I got there by talking to manufactures and racers to find what I needed. I suggest you do the same, to not do so will cost you big time both in costs and safety. There is also some tricks that you can deploy to help your cause but first you will have to settle in with a better setup. Lots of luck, you've got some homework to do. Signed- teacher Ron,,,,,,,,,,,,,,
cobrashock

[speed220mph]

You haven't complained about the pressure plate, so I assume it's ok. The disc is for sure what's giving you problems by giving up from the excessive heat. Organic facings coupled with high torque and a lot of slipping ensures certain failure. I've have excellent success in curing this same problem with ceramic--three puck per side--friction facings. These things love the heat and friction coefficient increases as they get hotter. One thing you've got to watch with this type of disc with mechanical linkages is the loss of free play because the facings get thicker after they are first used. Consequently, you have to readjust your clutch linkage. But if you're using a hydraulic linkage, it will self adjust.

[Ant]

Speed220mph:

I agree the paddle type clutch with individual facings that are similar to brake pads, I used to race a car with one in and it was a turbo gang buster type on off power and this clutch handled it real well!

Tommy:

I think its worth consulting someone who has been there and done that, look at the pressure plate check it out, see what is the best single plate lining to use, for one reason a good lining should be easier on the flywheel!

Regarding ceramic/paddle type these are great and may even be self contained or a throw away flywheel side face, as the flywheel wear will go up, but that may not be a problem as everything wears out eventually!

Final option a purpose race multiplate clutch, these last real well, if there not driven in heavy traffic, I used one in my 650bhp BB Cobra it was bolted to a flex plate and it drove real good once you got used to it, the only thing is the plates wear, not real expensive to replace the clutch pack, some guys get several years out of them racing.

I would be very curious to know what other guys are running for the road and track with 400 - 550bhp!

[Tommy]

Does anyone have personal experience with the SPEC Stage 3 clutch system?

[kevinR]

I'm not clear if you are using your car for racing only or for street as well. If it's racing only, I use a tilton triple (7.25") for the track only. The car is run pretty hard and the clutch wears extremely well. I wouldn't recommend this for street as getting into first can be a more sensitive endeavor.

[cobrashoch]

Ceramic disks wear the whole setup, pressure plate and the flywheel facing. Usially when the disk is shot the whole works will need replaced, but I agree they will generally last a bit longer on the street. I also had problems with them a few years back on making stickey shifts when they got hot, but they tell me that isn't a problem nowdays.
For me though its got to be a pro "long" style pressure plate. That way you just change the disk every two seasons or so to inexpensive bonded (not rivited) racing organic disks. And a Pro clutch pressure plate is easily rebuilt and still cheaper than buying stock pressure plates.
Another option is to look at the new Mcloed soft-loc clutch that the pro 5.0 boys are using. Don't know how durable they are on the street though.
Multiple disk clutches are horrible on the street because they are either "in" or "out", no in between. But they are the best for racing for several reasons.
So ya see it's about how much you want to do, how often, how much money you want to spend, the intended use and so on and so on. Kinda like the process you went though when you thought about buying a Cobra, ya think?
Cobrashoch

[James Neal]

Check out the pro 5.0 sites and stang sites,Folks tell me there is a hot triple that can be streeted ,8" I believe by QuarterMaster out of Lake Zurich, Illinois there in the back of your Stang Magazines.I believe A.S.S.C. are using them on there Toys a source tells me, Ill be checking it out myself.

[wtcobra]

Been there and done that. McCleod twin disc is your best bet for all around use. My advice is to go through David Kee, and let him deal with McCleod. I would also strongly suggest an aluminum or very light weight steel flywheel for best performance. I run a Jerico tranny with my twin disc and have been very happy with the clutch. David Kee, I think, runs one in his car, plus David is very knowledgeable about what will work. Good luck.

wtcobra

[M. Farcus]

I've torn up a few....mostly from drag racing which I don't do anymore....
I've run up to 500 hp thru a single disk adjustable pressure plate, mcleod unit, 4 blade puck brass puck type with spring center....on aluminum flywheel with steal insert...chatters a bit after its hot...but not to bad..ok for street. Mecleod made the disk up for me...its not in the catalogue with a sprug center...or least it wasn't..haven't looked in years....Call Red at McLeod...or David Kee.
I've also installed the mcleod street twin in several cars...works fine but rattles a bit when in neutral and also heavy in my opininon but will not slip.
Currently for road race only I'm using a QuarterMaster 5.5 triple disk...nice unit, very "on/off". Would not recomend it for the street....you "can" feather it, but it is not good for clutch.

M

[BPWilliams]

I have used my Mcloed Kevlar clutch at the track, and on the street. My car is 2610 lbs and I run a wedge 429 @ 500hp. I was told by Lone Star, and Mc loed to use a 12" clutch with the light car. so far so good, the thing on a road course is be "SSSMMMOOOTTTHHH" It will save your gear, and better your lap time. Aluminum Flywheel, Mcloed Pressure plate, and Kevlar disk set-up was not cheap, but it does hook-up. I read in another e-mail that if you beefe this up it will locate your next weakest link...... Keep it above 100.........

[Jahred]

Having to re-do my clutch set up due to slippage. I think I am going with a 2800 LB Ram Long style pressure plate with their 900 Series Clutch. (Sintered Iron)

Has anybody used this in a 600 HP car?

The aluminum flywheel sounds like a good fit for more horsepower applied and softer launch. Anyone have thoughts on that front? Any suggestions on other set ups?

[Cracker]

Like BPWilliams I am using the McLeod Kevlar clutch and pressure plate along with their Hydraulic Throwout bearing assembly. The clutch is the 12" variety and has provided nothing but wheel spinning grip. One big advantage we have with Cobra's is the weight of our cars and the light rear end. The tires are typically going to break lose well before you incure sumstantial clutch damage or slippage (this assumes you have enough power in that 514 to accomplish this ). Best of luck!

Tony Hull
Cracker on CC

[Bob Putnam]

Just in case...

Use a hose between the clutch master and slave that's at least dash-4 size.