Bullet Proof Clutch?
Thread Starter
Racer
Joined: Dec 2000
Posts: 279
Likes: 7
From: L.A., CA.
Bullet Proof Clutch?
After searching the clutch posts I still can't decide on a clutch upgrade for my 96 ZF6 LT4.
I just smoked my TPIS supplied single mass, Ram? disk with stock LT4 plate.
It didn't outlast a set of Kumho's.
Everybody seems to have a conflicting experience/opinion.
For a single disk setup with a diaphram plate what is the most reliable?
I don't care about chatter or noise, it's just for track days (RR not drag).
My best guess so far is the Ram 6000 series.
I just smoked my TPIS supplied single mass, Ram? disk with stock LT4 plate.
It didn't outlast a set of Kumho's.
Everybody seems to have a conflicting experience/opinion.
For a single disk setup with a diaphram plate what is the most reliable?
I don't care about chatter or noise, it's just for track days (RR not drag).
My best guess so far is the Ram 6000 series.
Melting Slicks
Joined: Apr 2001
Posts: 2,474
Likes: 1
From: Drive it Like You Hate it Cincinnati OH
Re: Bullet Proof Clutch? (Zpeedstr)
I had a centerforce Dual Friction in my '89 and could not hurt it... Due to lack of funds, I currently have a stock clutch back in the 96...
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: Bullet Proof Clutch? (Zpeedstr)
Since you are willing to put up with the noise of the single mass flywheel why don't you go with a Mcleod Street Twin. Sure it's a dual disk but the only mod really required is the single mass flywheel which you already have. It's rated for 1200 hp up to 7500 rpms. I promise you won't toast that one.
Instructor
Joined: Feb 2002
Posts: 183
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From: nthridgeville ohio
Re: Bullet Proof Clutch? (Nathan Plemons)
I went from a stock to a centerforce dual and can tell you that the dual after about 500 miles of not babying it is really great . man this thing really grabs----impressive.
Le Mans Master
Joined: Oct 1999
Posts: 9,713
Likes: 3
From: Sachse Texas
Cruise-In I Veteran
Cruise-In II Veteran
Re: Bullet Proof Clutch? (Zpeedstr)
If you are not drag racing it, I would suggest the McCleod Twin disk as well. It is expensive, but comes as an assembly with flywheel, two disks, throwout bearing, and pressure plate. It runs anywhere from ~$900-1200. It is the bulletproof solution for non-drag racers. I find it too unforgiving in drag racing because it will tend to find the next weekest link in the drivetrain.
The other heavy hitter is the SPEC, but some people have had trouble with the SPEC units. I ran an early model Stage 3 and the only complaint I had was a low RPM rattle that was due to the clutch. Nothing was wrong with it as long as you don't drive under 2K rpms or could deal with the rattle. I chose to put a McCleod single disk I had back in and change them once a year (~5K miles).
The other heavy hitter is the SPEC, but some people have had trouble with the SPEC units. I ran an early model Stage 3 and the only complaint I had was a low RPM rattle that was due to the clutch. Nothing was wrong with it as long as you don't drive under 2K rpms or could deal with the rattle. I chose to put a McCleod single disk I had back in and change them once a year (~5K miles).
Thread Starter
Racer
Joined: Dec 2000
Posts: 279
Likes: 7
From: L.A., CA.
Re: Bullet Proof Clutch? (Zpeedstr)
After some more research and talking to TPIS, Ram, and Mcleod:
The pressure plate for all LT4's pull clutches is made by Valeo in France, factory or aftermarket. Therefore, there is no choice for a stronger single disk pressure plate. The only way to get less slip is with more friction on the disk. The bronze has a coeficient of .35 and the iron has a coeficient of .5. Further, the iron does not lose friction with heat. So, the choice is iron. After a long and very informative and very patient talk with Red at Mcleod, I think that the best choice is the RevlocII 5201-07 (1 1/8x26.10.5"). He says the the 11" will have too much grip, but there is no 11" in the catalog anyway.
So here is the setup: '87 Vette 4+3 single mass flywheel, ZR1 pivot ball or midified equiv.l, Mcleod Revloc disk, stock plate & throwout bearing.
Good for 400hp?
[Modified by Zpeedstr, 6:20 AM 9/10/2002]
The pressure plate for all LT4's pull clutches is made by Valeo in France, factory or aftermarket. Therefore, there is no choice for a stronger single disk pressure plate. The only way to get less slip is with more friction on the disk. The bronze has a coeficient of .35 and the iron has a coeficient of .5. Further, the iron does not lose friction with heat. So, the choice is iron. After a long and very informative and very patient talk with Red at Mcleod, I think that the best choice is the RevlocII 5201-07 (1 1/8x26.10.5"). He says the the 11" will have too much grip, but there is no 11" in the catalog anyway.
So here is the setup: '87 Vette 4+3 single mass flywheel, ZR1 pivot ball or midified equiv.l, Mcleod Revloc disk, stock plate & throwout bearing.
Good for 400hp?
[Modified by Zpeedstr, 6:20 AM 9/10/2002]
Le Mans Master
Joined: Oct 1999
Posts: 9,713
Likes: 3
From: Sachse Texas
Cruise-In I Veteran
Cruise-In II Veteran
Re: Bullet Proof Clutch? (Zpeedstr)
Supposedly STAR (SPEC) alters the pressure plates to have more holding force. Something that may be worth looking into.
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Drifting
Joined: May 2001
Posts: 1,630
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From: Brandywine, Chester and Ridley Valleys Pennsylvania
Re: Bullet Proof Clutch? (Zpeedstr)
Yes, I think your revlock setup will be good for well over 400hp. Maybe you'll burn a pressure plate or "heat-treat" a flywheel with heavy doses of drag launches, but that clutch will keep grabbing.
Thread Starter
Racer
Joined: Dec 2000
Posts: 279
Likes: 7
From: L.A., CA.
Re: Bullet Proof Clutch? (Zpeedstr)
Just got the Mcleod RevlocII iron disk.
Looks hard as a file, should really grab, but:
The friction surface inner diameter is smaller that the pressure plate, while the flywheel surface matches the disk. There is about .375" of overhang. As the disk wears this will cause some wedge on the flywheel side, which will force the disk to cup. I talked with Red and Mcleod and he said that this is not a problem. I could machine off the extra friction surface or just put it in.
What do you think?
r
Looks hard as a file, should really grab, but:
The friction surface inner diameter is smaller that the pressure plate, while the flywheel surface matches the disk. There is about .375" of overhang. As the disk wears this will cause some wedge on the flywheel side, which will force the disk to cup. I talked with Red and Mcleod and he said that this is not a problem. I could machine off the extra friction surface or just put it in.
What do you think?
r
