I'll go with the LS7 clutch and a Fidanza flywheel then... Thank you for the advice

 

What is that gonna cost you?

 

$358.00 for a Fidanza Flywheel off Ebay.
$266.89 for a Corvette C6 Z06 Clutch from GMParts Warehouse ($649.99 on Ebay. Maybe it comes with a Z06 flywheel at that price?)

Although I also found out Fidanza makes a street Carbon/Kevlar full face sprung single disk clutch for $379

I'm intrigued...Has anyone used this clutch before?

 

I would seriously look into the Zoom twin disk and that's the one I am getting. No one does their homework like craigster05. When he decides on an upgrade, you can be rest assured he has done his research thoroughly .

Indeed craig, this is by far the best clutch for my application too. I am going for it. From what you said it will have factory pedal feel, can handle tons of power, and not chatter like other twin disks.
What more can we ask for?

 

$358 plus shipping, LS7 Clutch and Pressure Plate $276 plus shipping, plus about another $100 or so to balance. The GM stuff is made by this company and the pressure plate design is the real cause of the "dead pedal" syndrome, not the fluid as many think. Give me a call Sam, I learned this and a lot of new info at SEMA I think you'd be interested in....if I wasn't so lazy I'd type it in here (it would be a loooooong post).

 

I installed this exact clutch in a cammed Z06, it rattles and doesn't hide any gear lash, its beyond annoying like you wouldn't believe. It's pedal feel was off/on and it chattered first gear. Save your money and go for a better twin disc unit or buy a quality single disc unit. That Z06 owner has since replaced it with a quality RPS unit.

Ed

 

That's been the most frustrating thing about doing a clutch search. Everyone has their own opinions and there is much hear say without all the accompanying facts (like installation competence, hydraulic changes/mods, etc). Truth is, the clutch design on our cars is a weak point and leaves much to be desired, no matter what product is available. I watched a good friend and probably the best Vette shop here on LI install a CenterForce clutch on a Z06 (the shop has nothing but success with the Centerforce on cars up to 1000 RWHP). After the install, the owner hated it, wanted to go back to the stock for a variety of reasons (chatter, grabbing, noise, launch ability). After a month, the car was back in the shop, the clutch and flywheel failed. The owner was very upset, and the shop swapped everything out for a new Centerforce unit, exactly like the first. The second one drives like stock, the owner is the thrilled, and the shop is at a loss for an explanation, other than the 1st unit or the hydraulics were defective. Perhaps that is what happened with the unit you installed.

I'm not disagreeing with your information, I appreciate it and I am sure you are posting factual information to be helpful. But I have also spoke to 4 guys who currently use it, and swear it blows the others away...not from specs or opinions, but from actual usage. One of them, a respected board member (running a ton of power on a stroker, does his own wrenching, and his car regularly sees 1/4 mile track time) has been through just about every clutch you can name and can prove the abilities and performance of the Zoom on the track and off. I used the first hand information from speaking directly to these guys along with up close inspection of the various units and their specs and components in making my personal decision. After mine is in, I will post honest feedback about it, and let anyone locally who wished to drive it for themselves.

I'm sure their are other twin discs that are well made, good performing units, but the Zoom, besides being proven to me in the real world and on paper, comes in different power holding variants, with the ability to have a aluminum or steel flywheel (weighing in at 29 or 39 lbs total respectively), is priced competitively and most importantly for me, a very well proven customer service reputation. This suits what I am looking for, and believe me, if I am wrong, I will be the first to post it up here.

 

I agree with you on the install and differences from one unit to the next. I just know some people don't mind the gear rattle for instance and others don't even know they are getting it then hate it. This particular unit has no choice but to create gear rattle, especially in a cammed car, without springs in the clutch discs. I don't believe the clutch disc rattles at all because it's strapped. Another thing people aren't ready for is the extra rpm needed for takeoff from a stop with because of the light weight flywheel. For racing I don't think it's a bad unit at all, but for the street it leaves a lot to be desired IMO. Best of luck to you though.

Ed

 

Why do you want to replace your stock clutch if it has held up so well?

 

Excellent question... With this new flurry of activity I was just about to address it.
First let me repeat once again:
The bone stock, factory clutch on my 2006 C6 is NOT a Z06 clutch (they started using Z06 clutches on the '07s) and has about 39000 miles on it. It has NEVER slipped on me.

I want to replace the stock clutch for the following reasons, in order of importance:

1- I am making almost 300 more horsepower than stock, so while it does not slip now, it will eventually, because I drive a lot (I put 20,000 miles on my car in the firt 4 months I owned it!) and I drive it very hard. I would rather have this done now while I am not needing my car in winter than have to cancel a race because I am not sure the clutch is going to hold up.

2- While it is not really my favorite form of motorsport, I still plan to take my car to the drag strip a couple of times next year. I was told I am almost guaranteed to burn up the clutch if I try drag racing on it.

3- I really want a lightweight flywheel... I had it on 2 other cars and it was one of the best mods I had done to them, plus the weight I remove from the flywheel at the engine will help offset some of the weight I added from the supercharger, re-establishing the neutral weight balance of the car (I am also relocating the battery for that same purpose).

That's about it. Also, it is BECAUSE the stock clutch is holding up so well that I am interested in running a Z06 clutch instead of dropping $1500+ on a fancy aftermarket unit... If my non Z06 clutch with 39K miles works so well right now, a brand new Z06 unit should be even better, and I know I can count on perfect driveability, which is important when your corvette is your daily driver...

 

I agree...I've got 300 5k launches on my stock clutch, I love it. It's holding up like a champ, even at 450 rwhp level. I did have to take the spring out a year and a half ago when I put in the cam and went to 436 rwhp.

My high horsepower buddies tend to fry their clutches either at the track or on the dyno, not on street use. I suspect the OP will continue to get good service out of his clutch as he doesn't take his car to the drag strip, if he follows good fluid maintenance.

When I put in heads I suspect my clutch won't hold my drag strip abuse anymore so I'll put in the Zoom based on the good experience my shop has had with them. Just my 2c.

 

OK, So its about $800 for everything shipped and balanced. I've never had a clutch/flywheel assembly balanced, but allright, lets assume I do.

The Zoom D2 Series Twin Disc Clutch with the Aluminum flywheel is $932.70 Shippd, plus you have to get a throwout bearing. I agree that for those extra $150 or so the aftermarket option makes a lot more sense since it is designed to handle a lot more torque and thus should last longer. The Zoom is also a lot lighter.

There is, however, something that really concerns me about the Zoom twin disc clutch: if you look at the images of the unit, it appears as though the discs are unsprung... Unsprung discs have absolutely zero dampening upon engagement.. Unite that with a much higher coeffcient of friction compound and a stronger pressure plate, and I am really hard pressed to believe those "drives like stock" claims.

Speaking of clutches that "drive like stock", I have had installed on my Subaru STI:

Exedy Organic (worked great until I started making a lot of power)
ACT Organic (Fantastically heavy clutch pedal)
Exedy 3 puck Ceramic (chattered every timeit engaged)
Spec Stage 1 (junk, slipped the very first time I got on it after te 500 mile break in period, continued to slip for the next 1000 miles even fom a roll untill I replaced it)
Spec Stage 2.5 (complete junk, slipped from a roll every time)
Spec Stage 3: Six puck cermet (Chattered, harsh engagement, slipped if you got it hot from any kind of launch)
Spec Stage 3+ (complete, absolute crap. The pressure plate shipped so warped that my mechanic refused to install it. They tried to blame me for it, then they tried to blame the mechanic, I had the shop call them, they blamed UPS for warping the disk even though it was completely new unscratched in a perfect condition box and had been warped in a Dish shape!), so they sent me a new one. That clutch slipped every time even from a roll).

So, 6 aftermarket clutches, and here is what I learned:
There are only two ways to increase the holding capacity of the clutch:

1- You increase the clamping force making the pedal stiffer

2- You increase the coeffcient of friction of the clutch disk making the engagement harsher. Make the uK high enough and it chatters too.

It is always a compromise... That's why I am leaning towards the Z06 clutch: I already know how that drives... For every single aftermarket clutch named on this thread, I can find at least a couple of posts complaining of noise, chatter, harshness, stiff pedal, etc... If I get stuck in another 3 hour traffic jam driving to New York on the Verazano bridge and I have to do it with a clutch that was designed by a drag racer, I am going to want to sell the car

I'll give you a ring later on tonight; I'm not totally against the Zoom but I'm also not convinced it is as "streetable" as they claim, just because everybody claims their clutch is streetable For me, it is not streetable unless I can drive across the entire country a 4rth time with it on my car, and get stuck in traffic several times along the way.

 

That's the truth for sure....

The one thing that everyone I spoke with agrees on, the extra heat from headers etc is casuing the fluid problems (engagement and release) and the self adjusters/diaphram of the OEM pressure plate to hang up and keep the pedal on the floor. Be sure to insulate the clutch lines as much as possible. I'm going to go one step further, I'm going to have the headers and cats coated while they are out, going to insulate the lines and add a remote bleeder. I'm also going to do a new slave and bearing even though I only have 11K miles, because if I don't, I'm sure it will come around to bite me.

As a side laugh for everyone, when I got my car in 06, I got the recall for a defective flywheel, which would cause premature clutch failure. I brought it back to the dealer, who was a friend of mine who was honest and said they hadnt done one yet and didnt want to experiment on my car. He told me if and when it wore out, not matter how many miles, he'd replace it free of charge with the replacement, which was a z06 clutch and flywheel. He even put it in writing for me.

....And of course, the dealership went out of business 6 months ago...

 

Great Thread!!! I am having clutch issues to. I am getting that Pedal to the Floor problem!!! I agree that the headers are causing it cuz of heat!

 

I disagree. Bone stock cars will do that on the drag strip with factory exhaust manifolds... Heat is usually the culprit with those pedal to the floor issues, but the heat normally comes from slipping the clutch excessively on a drag launch, and then the hydraulic fluid boils because the slave is so close to the clutch...

 

Heat is certainly not helping but I'm with Craigster; The self adjusting pressure plate design of the LUK's is also a contributing factor. I got pedal to the floor bad last weekend when I dynoed. The clutch was obviously engaged the whole time. No slippage.

 

How long will that Zoom dual disc clutch last? What is used for the disc material?

 

The zoom 600hp clutch uses organic, the 900 uses kevlar, and there are no springs in the clutch disc.

I will vouge for their customer support

Mr. Craig,

Are you using an adjustable master cylinder with the dual disc zoom?

When did you get and install your clutch?

How many miles?

I will pm you the rest of the story as to why I would appreciate your help in answering this question.

Thank you and

 

I went with RPS Twin Disc a few months ago and love it. Very little clatter and definetly grabs my 600HP.