C4TT

Hey guys...
The guy who built my car has given me a new option over the painfully stiff racing clutch I have in now. He suggested the 993 Turbo pressure plate, and a GT2 Clutch disk. He seemed to say they could cope with the power.

Wondering if anyone is running this setup, and approx cost of these items.

Thanks,

Greg

911/Q45

Our opinion of stiffness would be less helpful as our clutch is power assisted.

C4TT

Great point...
Any experience with the clutch tho?

Thanks,

greg

JJayB

The GT2 pressure plate and disc will work well up to 520-540 ft lbs. of torque. If you track your car and run slicks you will need to get more clamping force than the stock GT2 pressure plate offers. I believe that the stock 993tt clutch is not designed to handle 500 hp. Why is your mechanic advising to use a 993tt pressue plate if your making 600hp?

Glen

There is a new Sachs PP that offers significantly more clamping force than the old TT or GT2 piece. It can be had at SSF, just ask for Joe Anselmo and the upgraded Sachs PP.

C4TT

SSF? I will do a search...
Awesome input guys. I suppose my mechanics, (who I should add do nothing but tune Twin Turbo air cooled porsches and have done so for 15 years) recommended that setup. I guess the pressure plate of the 993 is sufficient for the power.
You have to understand that most of the time, I'm running around with 450HP in low boost. Only every so often, do I kick it up to high boost or 600hp.

Glen I will check this clutch you are talking about.

Thanks

Greg

viperbob

You may have trouble getting the pressure plate from SSF unless you are a distributor. Fortunately I am, and my new Sachs GT2 pressure plate is being installed as I write this. The new one (this model year) is designed to withstand 800 lb ft of torque (1100 nm). This is an increase of approx. 15% over the one sold last year.... They are not cheap BTW.... List price of almost $1,200. Also, your clutch needs to be up to the task, not just the pressure plate...

TB993tt

Bob
Which disc did you decide on - organic or sintered, sprung or unsprung ?

viperbob

I'm going with a Clutchnet.com hybrid. It uses carbon fiber buttons on one side, and organic on the flywheel side with a sprung hub. We'll see how this works.... The guys there are pretty cool and will make just about anything you want and they ship the same day. All this and reasonable prices....

TB993tt

Bob
Please keep us informed of how it performs, my organic sprung disc is living on the edge in holding the torque, even with the help of the FVD 980NM press plate.
Thanks

poorb0yw

TB993tt- You may want to check out the clutch setup I just installed into my car. I've posted extensively about it on the 993 forums. Tilton twin disc Carbon/Carbon Matrix with thier clutch pack housing and pressure plate. Same stuff they use on the leading edge of the space shuttle nose. In any case, its was tested to 1100 ft-lb of torque. Also they provide two extra shims so u can just shim the pack if the carbon matrix discs ever wear down.
A proffessional drag race team I have spoken to tells me this is the last clutch I'll ever buy. They run insane amounts of torque in thier car and drag race starts are nothing but violent. After an entire season the carbon discs had worn down less than a quarter of the amount necessary before justifying the need to move on to the next shim thickness.
Knowing the amounts of torque your car puts down and the number of clutches you have gone through it may be worth your while to look into this option.

JJayB

Princeton
How street friendly is the Tilton set up? Every race clutch super hi tech carbon clutch I've driven won't pass the 5pm freeway crawl. The key is having durability without loosing drivability.

poorb0yw

JJB- I've driven it thru Houston traffic many times now. Even the well renowned 6-10 / 59 interchange.
The Tilton mettallic race clutches are indeed on/off units. However thier carbon/carbon line was designed to allow a little slip. Also the included hydraulic release bearing keeps the pedal feel pretty much the same as stock unlike other stiff race clutches.

TB993tt

poorb0yw
My concerns are well put by JJayB - I have used a sprung metal disc before was "useable" in stop-go traffic but in reality, the tt would be left in the garage if I knew I was heading for traffic (becoming the norm for our roads now) so I opted for the 980NM press plate with RS/GT2 organic sprung disc set up which has proved just as user friendly as stock. I have to avoid full throttle between 4000rpm and 4800rpm in 4th/5th/6th where the torque makes it slip. The disc viperbob refers to looks pretty hi-tech and promising - If the stock clutch "take-up" is 100 and a metal disc race clutch is a 0, I would rate the sprung metal disc at a 45. Any idea what # you would give your carbon set up ?
Thanks

C4TT

My current carbon compound clutch is more track than street. It is like an on/switch with no modulation whatsoever.

Firstly my older generation setup has no assist like your deluxe 993s.
Secondly, without the right amount of throttle, she WILL stall. Too much, and poor engagement will make the whole car shudder...

I have gotten used to it, but have only gotten stuck in traffic ONCE, and started losing it after about 40 minutes... I was talking to myself, cursing.. It wasn't pretty... All while supporting my left knee from the pedal pressure... Not good.