I know that ya'll are likely screaming at your computers now, as this issue has to have been beat to absolute death; but hear me out.

I would like to get input from anyone with an aftermarket clutch so that a list of the clutch options, and the characteristics of each of those options.

Q: What am I looking for here??

A: 1. What brand/model of clutch you have personal experience with.

2. What are the characteristics of it?? Is the pedal really stout, or...?? Perhaps compare the pedal with your aftermarket clutch to the pedal with a stock clutch (with the aftermarket unit, is the pedal about the same as stock, 25% stiffer, 100% stiffer, etc...). Does the clutch engage smoothly, or does it grab/chatter??

3. Any problems you have had... for instance, it seems that McLeod requires the use of an adjustable MC, and a LOT of people have problems getting it dialed in properly. Does the clutch slip when getting the vehicle rolling (i.e., coming out of the hole), does it slip when (if) your nitrous hits, does it slip once boost really builds up?? Let us know.

4. Durability/wear. Did the clutch work properly when you first installed it, but then start slipping 6 months later?? Have you over heated/warped a flywheel??

5. Use of the car. Is it an all-street car?? Is it a street/strip car?? Is it a dedicated drag car?? Is it a road race/autocross car?? You get the idea.

6. Current mods to the car and/or dyno numbers... obviously, someone with 360 RWHP doesn't need the same clutch as a bottle-fed 427.

7. Other factors regarding the car... vehicle weight if you have it, rear gears, type of tires used (street, drag radial, cheater/DOT slicks, full slicks, road race/autocross tires, etc...)

I know that all of this is a pain in the ***, but that's one of the things I love about the 'net, and, specifically, technical discussion forums such as this- the information is there, you just have to ask the right questions to the right people. Perhaps if we get a good, informative thread going here, a mod can make this a sticky towards the top of the page...

TIA, ever'body.

 

Well, since no one is biting on this, how 'bout I tell ya'll what I am looking for, and hope that someone has a suggestion...

The car is an '01 Z28 hardtop, and the car goes on the dyno this Saturday (with the stock clutch in it). I'm hoping to see 450-470 RWHP, and a touch over 420 RWTQ. I haven't weighed it, but let's assume a 3600 pound curb weight (no weight reduction, and none is planned). No N2O or FI is in the plans. Car will be 3.73 or 3.90 geared, and will be running on 315/35/17 street tires virtually all the time, as it is a street car oriented towards road racing. Car may see a few passes at the track on 28" tall cheater slicks. I'm looking for something that will hold the power that I'm making, and not chatter too bad (if at all). A pedal perhaps 50% stiffer than stock would be acceptable.

Note that I don't need something that'll hold up to 20 6400 RPM clutch dumps a night on slicks, but if the clutch meets my other criteria, then the more grip, the better...

 

I have the spec stage III with kevlar disc, I have nothing but good things to say about it, when first installed, it chattered some when starting from a dead stop, but after about 10k miles has virtually no chatter. The hardest thing to get used to is the very small amount of clutch pedal movement between (starting to engage) and (fully engaged) clutch. I have nowhere near 450hp, but this is one hell of a strong clutch, I have put 48K miles on mine and it has never slipped. I can still get in 2nd gear about 2500rpm, push in the clutch, rev her up, dump the cluch and the rear kicks sideways and she's gone.

 

I'll put my vote in for the Spec III ceramic. Works great with my setup and although I haven't dynoed it yet , I will be doing so next week at Agostinos and expect around 450 RWP and 450 RWT after it gets tuned. The Stage III ceramic is working flawlessly.

 

So what is the difference between the Kevlar and Ceramic Stage 3 Spec clutches? Which one is better?

 

I actually just prdered a new clutch for my car. I went with the RAM VDS 900 series. I searched alot in these forums and it seems that this is the clutch that will hold up to pretty much anything you throw at it. I have read plenty of reviews and it seems that the RAM master cylinder is alot easier to deal with than the McCleod( they both are adjustable). I called Ram and spoke to John(I think that was his name.) He told me because I have 3.42's there may be a small amount of chatter and he emphasized small. I will get it next week , I will keep you posted. Overall for a clutch that is way more aggressive than stock driveability doesn't seem to be affected very much from what I read. Take into consideration that I haven't driven with it yet but I honestly researched for hours on this subject before making my decision.Hope this helps .



Shane