Clutch Experts Needed : Big FTLB Quest

[doozer]

Experts Needed: Ok so if you have the following

Blueprinted SBH 930 with Billet Side Plate and external cooler circuit
GT Torque Biasing Diff
Cryo'd 930 CV's and shafts - http://www.300below.com

What clutch do you use for 750+ foot pounds of torque?
I need a clutch that I can slip a little and is not an on-off switch, but I dont want it to go shrapnel when I put my foot in it.

Centerforce?
Tilton?
Spec?
Other?

Thanks
Todd

[doozer]

No clutch experts?

[doozer]

Seriously! Anyone? Anyone? Buler? Buler? Anyone? You must all drive automatics

[RarlyL8]

The only fella that comes to mind with a 700+ HP 930 would be AMAC or Stephen Kaspar of ImagineAuto. Give him a call.

[Quicksilver]

On this board I would bet the expert in this case is Juan Ruiz. He has broken anything that will break on his "HP Junkie Mobile".

You need to be looking at double or triple disk setup.

Centerforce? Bzzzzt. Centrifugally loaded pressure plates aren't a good idea for a shifting application. It is a bandaide for an under designed pressure plate/disk system.

Tilton? Great stuff but I'm not familiar with their longevity for street clutches.

Does anyone know what the torque holding specs for the GT3 clutch are?

Wayne

[doozer]

I had a couple of high torque Porsche guys tell me that Centerforce clutches fail.

But then Patric Motorsports quotes me one for this application CENTERFORCE DF255255.

Also AMAC said his centerforce worked for 750hp ( dont know the torque )

Ryan at TheRacersGroup was saying maybe use a Tilton.

Scott at Renegades ( the v8 crew ) said he built his own and to use his.

???? I am lost ????

[WydRyd]

I hear the SPEC Stage3 (SP033F) will handle that amount of power.

[doozer]

Aha! Please tell me all that you know about the SPEC!

Thanks WydRyd for the input!!

[TimT]

We had a Spec clutch in our 935 clone, It didnt last the season. the straps broke and started sawing the bell housing.

The Spec clutch was replaced with a Porsche Motorsportsunit

the car is powered by a 3.8 single turbo engine mated to a regeared G50 with all the mods, steel synchros, billet side plate Guard dif.

The tilton can work, if you get one of the multi plate clutches, 3 or 4 disc .But you have to get a special flywheel, and modify a T/O bearing to work, as well as add a hydraulic master/slave if your car doesnt have it.

[doozer]

3 Stage 1989 1989 3.3L Turbo G50 SP033 $1199

SPECT: http://www.specclutch.com/specMain.html


STAGE 1 - Street & Strip. This kit features high clamp pressure plate with a steel backed woven organic sprung disc. The organic disc offers smooth engagement, quiet operation with light pedal feel. This is excellent for daily driving and occasional racing. All clutch kits include release bearing, pilot bearing and alignment tool (if applicable). *Note: Cars with dual mass flywheel will come with unsprung disc.


STAGE 2 - Street & Strip. This kit features high clamp pressure plate with a segmented chatter free Kevlar sprung disc. The Kevlar disc offers smooth engagement, quiet operation with light pedal feel and increased torque capacity over Stage 1. This is excellent for daily driving and occasional racing. All clutch kits include release bearing, pilot bearing and alignment tool (if applicable). *Note: Cars with dual mass flywheel will come with unsprung disc.


STAGE 3 - Ultimate Street & Strip Clutch!! This kit features high clamp pressure plate with a ceramic sprung hub disc. The disc is a 3-piece design sprung hub to deliver sharp aggressive but yet smooth engagement. Quiet operation with increased torque capacity over Stage 2. The ceramic material is highly durable and heat resistant. This kit is excellent for daily driving and racing especially for cars with higher output engines. All clutch kits include release bearing, pilot bearing and alignment tool (if applicable). *Note: Cars with dual mass flywheel will come with unsprung disc.


STAGE 4 - Serious Road Racing & Drag Racing Clutch!! This kit features high clamp pressure plate with 6 pad copper ceramic disc. The disc is a 2-piece rigid design to deliver sharp aggressive engagement. This style of engagement is ideal for racing where quicker shifts are required to beat the competition. The disc is lightweight for better performance since the disc is unsprung. Also the unsprung hub reduces the chance of failure which is ideal to win races. This kit is excellent for race cars with higher output engines. All clutch kits include release bearing, pilot bearing and alignment tool (if applicable).


STAGE 5 - Drag Racing Only!! This kit features high clamp pressure plate with an iron disc. The disc delivers extremely sharp, aggressive engagement. Ideal for drag race cars ONLY (never street driven) where the highest torque capacity is required. The disc is also lightweight for better performance since the disc is unsprung. All clutch kits include release bearing, pilot bearing and alignment tool (if applicable).

[doozer]

Thanks TimT, what would you suggest? Tilton??

[TimT]

Porsche motorsports would be the easiest

the tilton is fine but a bit of work, also the MOI is reduced which is a good thing on a track car, not so desireable on a street car

[doozer]

Just found on another bbs :

New Tilton 3 Plate carbon carbon clutch 1455 lbs ft of torque.

[TimT]

that clutch is in the neighborhood of $3800

[doozer]

Tilton - wooo - The clutch Hydraulic throw out bearing and transmision adaptor, $3,589.20 - but they are rebuildable!!

[doozer]

http://www.tiltonracing.com/content.php?page=list2&id=43&m=d




OT-II 7.25" (185mm) Carbon / Carbon Clutches
• General Information / Features
- 7.25" (185mm)
- 1, 2, 3 & 4-plate
- Push-type release
- High strength one-piece lug-drive cover
- Smooth engagement
- Open cover design for cleaner and cooler operation
- Individually tested for clamp load, release load and torque capacity
- Includes complete build sheet
- Includes three pressure plates to compensate for wear
- Low rebuild cost


• Typical Applications
- Circle Track, Drag, Endurance, High Performance Street, Off-Road, Road Racing

* 1-plate
* 2-plate
* 3-plate

[doozer]

O' $%#^ , I guess the family REALLY doesnt need Christmass presents - you know it is the thought that counts

[Shuie]

cool project doozer! Thats going to be a real asskicker of a car! Not to hijack or anything, but what are you doing for brakes? Holy **** that thing is going to be fast. Hopefully it will stop as good as it goes

[doozer]

Thanks Sherman!

TRG Big Break kit from Ryan at http://www.TheRacersGroup.com.
It actuall even stops really well with the big tires.

I can always turn hard to port and throw out my anchor..

[poorb0yw]

I'm using a Tilton twin disc carbon/carbon. They seem to actually rate them at lower than what they can handle. My specific clutch was tested to hold 1100ft-lbs at thier facilities.

I can attest to the rebuildability (takes approximately a week) and low cost of rebuilding the clutch pack.

Add about 1k for a flywheel that will match. You'll also have to get clutch pedal stop and some custom hydraulic lines made for the throwout bearing.

The engagement is indeed smooth but you'll have significantly reduced clutch pedal travel to work with. Definitely something to get used to.

Theres another member here that had the 3 disc setup installed a few months back. Haven't heard an update from him yet.