Kevlar Clutch Opinions and Issues Help

[wrogers55]

What are the street manners like with a kevlar/kevlar clutch setup. It needs to hold 550HP on street tires and no racing or hard launches. Kevlar may not be necessary but I don't want to replace the clutch again. What are the issues if any, chatter, smooth engagement or other issues? Any special issues with the pressure plate when using a kevlar clutch. Got a lot of good advice so far, but I need make a decision and to pull the trigger soon. Sun is finally out in California.
Thanks, Wayne in Gilroy

[RICK LAKE]

wrogers55 Wayne clutches are worn out by people and how they drive thier cars. I had a 72 C-30 truck with 3 on the tree. The truck went 90K miles and was sold to my friend. He has done body work, and replace the valve stems for the oil usage for blue smoke startups. It now has 130,000+ and still running the same clutch. It's organic 12" for heavy duty usage. It's all about how much you slip the clutch when taking off, down shiftings, and the 5,000 rpm drop the pedal burnouts.
IMO a clutch is a wearout part and designed to protect the rest of the drive train. Most clutches have spring loaded hubs to absorb the shock of the power going to the rear wheels. Clutch is the cheapest to replace at $375 for a complete setup, no flywheel. You break a trans or rearend you are looking in the $1,000.00+.
Kevlar clutches need to be broken in and get heat cycles. Breakin on a Zoom setup was 500 miles before any hard driving. You have 550/500 hp tork motor. Go out and buy a stock 11" heavy duty clutch from Pep boys, Auto zone, R&S and drive the car. Stay away from multi clutches unless it's the Mcleod street twin disc setup. This clutch will hold your motor and more. It needs to be setup and might make a little noise when driving.
Unless you are going track and racing hard, go stock. I didn't see what trans you are running but here again, clutches will give up faster than a trans and save it. Rick L Ps Get a 2,600 lb or 2,800 pound pressure plate. You need nothing heavier. Call Brent and get a complete flywheel and clutch setup would be the best way to go and cheaper than Jeg's or Summit.

[DAVID GAGNARD]

I put a kevlar clutch in my road race car a few years ago, nowhere in any paperwork with it said anything about a break-in, well, I found out the hard way at the track. it slipped like crazy in 3rd and 4th gear for the first couple of track sessions and once it cooled off it was o-k. I did find it wears a lot.......

Since then, I switched to a Ford Mototsport Cobra King Clutch set-up, the same one in my 65 fastback........Absolutely NO problems from day one and a lot less expensive than a kevlar clutch........

The one in my fastback has been in the car since the late 90's and has 25,000 miles of street driving, at least 100 drag strip passes, shifting at 6,000 rpms and about 2,000 hard miles on road courses and it still works like the day I installed it and has never slipped nor given my any problems. That engine makes about 350 hp/350+ torque.......

My race engine makes 472 hp and around 440 torque and the King clutch works perfectly.....

Even a standard replacement Auto Zone clutch would work fine for your application.....IMHO of course........

David

[vector1]

i purchased a clutch setup from quartermaster that is small diameter aluminum flywheel deal, the guy i talked to told me i would go through the kevlar pretty quickly, using the metalic twin disc setup and i can't tell the difference, just have to be careful about clutch slippage, with either one.

[blykins]

There are many types of dual friction clutches, some have bronze on them, some are Kevlar, etc.

Kevlar would be the one most likely to chatter with the dual friction clutches, but with a light car, you probably wouldn't have any issues.

I would always rather have more clutch than not enough, just in case you were to decide to bolt on a set of drag radials and try it on a test and tune night.

McLeod has some nice dual friction clutches that would be really streetable. Their Super Street Pro clutch is rated for 500-550hp, comes with a diaphragm pressure plate (low pedal pressure) and would be completely streetable (no Kevlar) with no ill street manners.

I can hook you up with a clutch kit and flywheel if you need one.

[Zoom This]

I've had a McLeod Kevlar clutch and aluminum flywheel in my SPF for going on 7 years now. It was replaced at 11,000 miles since I had the motor and tranny out for a rebuild. Replaced the clutch even though it still worked fine. The new clutch has 9,000 miles on it and the motor in front of the clutch is a 418W with 550 hp. Now, I don't do much track racing but I do like to bang the gears when the road is clear. Clutch has always been smooth to operate, no chatter and this is the first I heard of a break-in for a McLeod Kevlar unit. I'd buy the same clutch again when it's time.

[blykins]

If you read the fine print, most manufacturers have a 300-500 mile break-in period.

[RICK LAKE]

Instructions for all speed equipment have warnings and breakin times and mileage if you read the instructions on them. It's some times in small print but there. It's in red letters in my Zoom setup. Rick L.