Kevlar and Ceramic clutch packages (group buy)

John B

Sponsoring Vendor
#1
While researching components for my SLC build I found clutch options for the Graziano transaxle to be too expensive, too limited and too bi-polar. Because the transmission was OEM fitment for the Audi R8 and Lamborghini Gallardo, existing options were priced with those marques in mind and seemed to be a poor fit for the low rpm/high torque motor I planned to use for the car.

Clutch options largely fell into two camps - OEM-style and Racing. The OEM R8 clutch is a fine choice for a street-driven, lower horsepower build, but it was designed for a vehicle that produced only roughly 400ft lbs and made that torque higher in the rpm range - not to mention the flywheel and clutch are typically not balanced together. The racing clutches, like the one I ultimately put in my car, had fantastic torque-holding capacity but were thousands of dollars and terrible to drive on the street. I thought there should be a better option, so I created one!

I approached the manufacturer who manages HCF's (HCF Parts) kevlar composite disc rebuilding program for Ferraris and asked if they could design a kit for me. They came back to me with two options - a Kevlar composite disc option and a Ceramic disc option. I'll describe each below:

Kevlar fiber composite disc
Intended for street (and moderate track) driven vehicles where a smooth engagement is desirable. The disc material exhibits a wear rate of roughly 1/5th that of asbestos materials and 1/2 to 1/3 that of sintered bronze materials. It is designed to be used either dry or wet (as an unfortunate 512TR owner found first-hand when his gearbox developed a leak a year after install - see 8 year case study at HCF Parts) and is non-abrasive to opposing flywheel surfaces. This clutch package is appropriate for street driven vehicles making up to 750 ftlbs. For more abuse or more torque-holding ability, the ceramic disc option below is more appropriate.

Ceramic disc
Intended for primarily track-driven vehicles where the ability to withstand more abuse is needed. A tradeoff with the ceramic discs is a more aggressive engagement and less ability to slip the clutch on take-off. This clutch package is appropriate for track driven or extreme street vehicles making up to 1100 ftlbs.

Each clutch package will include a balanced assembly consisting of a steel flywheel, two clutch discs in your choice of material (one sprung, one rigid) and a heavy-duty pressure plate.

To hit a minimum order, I need to find 10 interested parties. Pricing at that level is $2,900 assuming a 6 or 8 bolt LS/LT Chevy motor flywheel design. Others can be supported for a small charge for setup - please email me at [email protected] if that's the case.

I think these kits fill an existing gap for friendly-engagement but higher torque street applications and cost-effective higher torque track applications. If you're interested, please respond here or reach out to me at [email protected].

Thank you,
John
 

Ron McCall

Bronze Supporter
#4
John,

This is GREAT news! Seems like a very cost effective alternative to what is currently available.
Can you please add me to the list for a Ceramic clutch?

Thanks,
Ron
 

John B

Sponsoring Vendor
#6
Thanks Roger, Rohan and Ron! I've got you down and will reach out in the next week or so to get your flywheel bolt pattern and finalize.

I forgot to mention - turnaround time should be 2-3 weeks... so I'll have finished clutch packages to you quickly.

Rod - I don't have the specs on the Hollinger, but I can have anything made. If you'll reach out to me by email with information on the existing clutch, I'm happy to get back to you with some options.
Best,
John
 
#10
I wanted to take a minute to share my excitement regarding the drop gears and new Kevlar clutch setup from John. I first ordered the new drop gears and then soon after, I discovered that he was offering a Kevlar clutch solution. This was great news to me because I had already burned up two SPEC clutches. I installed the gears first and then as promised, my kevlar clutch arrived just in time for a regional show in Irvine California. The car drove completely different. The clutch was quick to engage and felt very positive. The new gear ratio allowed my to start off without having to feather the clutch and I could actually use 6th gear on the highway.

Overall i would rate his products and customer service a 5 star experience. There was no run-around and every call and email was answered promptly and most importantly, answered honestly.

Thanks for the help and great products!

Shad B


A brief History:
I do not have a GT40, but I have the identical mid engine configuration in my Pantera. I am running a twin turbo 408ci Cleveland with the 6 speed Graziano box. I had similar problems that John had with the original drop gears being too high and I went through two SPEC clutches. I found John on this forum and I could not believe we were running parallel paths and he had engineered the solutions. Great products and service
 

John B

Sponsoring Vendor
#11
Many thanks for the comments, Shad! If I recall correctly you're running 700hp+ with your twin turbo motor config?
Glad to hear the car is back on the road and you're happy with how it's driving!

For anyone else looking for a clutch for their GT40 / SLC (or high horsepower Pantera!), we'll be offering these clutch kits outside of the group buy going forward. Some photos here on the website -

Clutch | HCF Parts

Best,
John
 
#12
A follow up on my previous post dated 5/19/18.......I now have about 800 miles on the new kevlar clutch and drop gears and everything is working perfectly. This is amazing, because at this point in the past, my SPEC clutch was slipping and basically un-drivable. I went through two expensive clutches before discovering John's kevlar offering. The clutch is strong and the new gearing is just right.

I still stand behind my previous review.......Overall i would rate his products and customer service a 5 star experience. There was no run-around and every call and email was answered promptly and most importantly, answered honestly.

Shad B


A brief History:
I do not have a GT40, but I have the identical mid engine configuration in my Pantera. I am running a twin turbo 408ci Cleveland with the 6 speed Graziano box. I had similar problems that John had with the original drop gears being too high and I went through two SPEC clutches. I found John on this forum and I could not believe we were running parallel paths and he had engineered the solutions. Great products and service
 
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