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There are some others that require dedicated flywheels:
McLeod Original Street Twin – dedicated flywheel, 10.5” organic discs, soli hubs, 6300-104 $1160
Ram Force 9.5 - billet hat, one sprung disc, one solid, up to 650 HP, organic, 9.5” dia, dedicated billet flywheel, 1800 lb clamp load 75-2130 – 454 bal aluminum flywheel 10 spline $975
I have a very light clutch pedal. Non hydraulic. Rate up around 1000+ hp. single disk for 26 spline tko 600. 168 tooth 11 inch. My choice of light weight SFI flywheels. Running for many many years. All for only $1100 or so, what more could I ask for?
The sad thing is C-19/shutdowns hurt lots of small businesses. See how these guys might help.
My opinion is that multi disk clutches are made for when reduction of inertia is the main concern. Like 69427 pointed out years ago, The diameter of the flywheel is as big of a factor as the weight when it comes to inertial mass. Look at a formulas for say a 40 pound clutch spinning 6000 rpm.
So you have to start on the front of the engine and use a small diameter lighter damper. Then it's the weight of the crank shaft. then the weight of the flywheel through pressure plate assembly. It all adds up to the total reciprocating weight.
I think the best setup I ever ran was the 22 pound 168 tooth 11 inch SFI steel flywheel. Just bullet proof. It's going back in with my 434. My 11.5 pound steel ring aluminum SFI is just trick racing stuff that I actually think flexes from the clamping pressure of my high power pressure plate if you drop the clutch. I think with time it would actually get induced flex cracks
I have a very light clutch pedal. Non hydraulic. Rate up around 1000+ hp. single disk for 26 spline tko 600. 168 tooth 11 inch. My choice of light weight SFI flywheels. Running for many many years. All for only $1100 or so, what more could I ask for?
The sad thing is C-19/shutdowns hurt lots of small businesses. See how these guys might help.
I have a NIB circa 2012 Street Twin that I am having my doubts about for some of the very same reasons you state Leigh. Will be anxious to see your results.
I wish I had all the answers for you right now, but I do not have enough of the car together for the street. I went with the RAM 10.5" Force #80-2135. I have the similar version in my 2001 Z06 and have for almost 14 years now. In my Z06 the pedal feel is great. The clutch release is a little tricky at first because you can feel disk 1 and then disk 2 release. You get use to it real quick. In that car the pedal effort is better than any single disk I have had before it. I think the Force 10.5 should not rattle like my LS6 clutch because it has straps. My LS clutch does rattle a little, but it has floater stands that are metal.
I have a NIB ciirca 2012 Street Twin that I am having my doubts about for some of the very same reasons you state Leigh. Will be anxious to see your results.
Great. When I call I will get specs on that one too.
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
I don't think will actually help you directly since I do not have any personal experience in these clutches. However, my friend has a 2012 ZL1 Camaro with about 900hp to the rear and uses a McLeod double clutch I believe and it works great for him, good enough to do 214mph at the Texas mile in 2019. I can ask if you like which one if you like. Also, the premier LS shop here in the valley uses McLeod as well on all their high hp vettes/camaro's etc...
I think your concern over having the Transmission Rattle with these Clutchs are only when using the ZF Trans in the the C4 Corvette era. These cars were engineered to use a Duel Mass Flywheel and when people switch to a conventual Clutch being it single or twin then yes it does rattle. Other manufactures also used this design and when a conventual clutch gets installed its the clutch that gets blamed. My Spec Twin makes weird sounds when disengaged but thats just the way it is. Its a way of telling everybody you have a twin disc.
I can tell you from first hand experience that the original McLeod street twin with one disc having a Marcel spring, will not release fully. My RST releases in .440 of an inch as tested on a press, does not rattle, and has lighter than stock pedal pressure. I am using a 12 pound McLeod aluminum flywheel and my 502 is internally balanced. Love the clutch.
Last edited by 69ttop502; Jun 26, 2021 at 07:25 AM.
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Originally Posted by 69L88
Buccaneer - can you share the name of the shop?
Sure...Cordes The owner Joe lives three blocks form me and the go to guy for tuning their lives next street over from me. Funny to see a C6/C7 with a drag shoot coming around the corner sometimes and a laptop in the pass seat. Sounds good though.
Last edited by Buccaneer; Jun 26, 2021 at 11:55 AM.
Had this chattering on/off switch McLeod in for about 25 miles and took it out and put in a Ram diaphragm in my slightly modded 427/435. When pushing on the clutch pedal, the firewall flexed so much, the brake pedal would move. If I could have found a n.o.s. GM clutch, I would have bought it.
This was about 8 or 9 years ago. I believe it was a street twin, Summit part number MCL-64001-00-04. I think it is no longer available. Can't imagine why. Bought it and a Hurst shifter and repro C3 shift handle and ****. Sold them both.
I used a 88762 stock replacement clutch and ram 1501 flywheel. This is fine for my street car application. If I were to do it again, I'd just go with a 88762HDX clutch. I've installed dozens of Exedy twins, but they were for C5/6 LS applications. I do not think Exedy makes a twin for bbc's.
Twin Disc Options - pros & cons
