Racing Clutch Wobble or Flutter??

[REDSC400]

Hi Gang!
My cobra, when built by the first owner, had been configured and built with a racing clutch, pressure plate and such.

First off, I just want to say the car drives very very well.

The only quesitonable behavior it exhibits is (in my mind) as follows:

When the car is stopped and you are in first gear, and you try to let the cluch out very very slowly, you feel what can be called a "flutter" or "wobble". I was told by the original owner that this behavoir is because the clutch is an IN or OUT racing clutch and it does not like to be released slowly or feathered. IN or OUT no halfway stuff is what it likes.

Now you do not feel any wobble when in gear, nor in changing from 1st to second or any other gears. Just from dead stop and only if you let up on the clutch in a slow manner. It takes a bit of getting used to. One of my buddies, who has a Porsche tried it and said it felt just like his competition clutch... in or out , however his does not have as much wobble or flutter.

Should I be concerned about this wobble or just consider it a "feature" of this clutch and pressure plate setup?

Thanks for your time....

[Rick Parker]

Art:
If you in fact actually have racing clutch, some of them do not have the coil springs in the hub or the wafer spring (marcel) between the two friction surfaces. The lack of these means that is as you have discovered "ON or OFF". They do not allow for slippage without excessive heat buildup. The trade off is generally greater torque capacity in a lighter package, with less rotatioanal weight.

Rick

PS: Just another point to keep in mind: Sometimes the disc or the flywheel will become glazed due to contamination (oil) or heat from slippage (intentional or not) in spots and will cause poor engagement or chatter while engaging.

[Lyle]

My stock '93 5.0 EFI w/ T-5 is exhibiting the exact same behavior. The "wobble" or whatever is happening shakes the whole drivetrain, but on ly under those specific conditions. Very aggravating. My set-up has the base Ford Racing Performance Parts clutch, which I believe is not much stouter than the stock unit. I know it has hub springs. It would seem that there must be some inconsistancy in the friction at the slow slip point to cause the shudder, but I don't know what would cause that inconsistancy. Either the flywheel, the clutch disk, or the pressure plate wold have to have some variation, but as all three are round, and presumably uniform, I am at a loss. Any advice will be appreciated.

Lyle

[Katauskas]

I just replaced my RAM racing pressure plate on my FE for a diaphram type due to excessive pedal pressure. Both did not exhibit any of the behavior that you are describing. However, as Rick mentioned, I do have the coil springs on the disk that allow for smoother clutch engagement.

If you do have a true racing disk, then this may be possible, but I would make sure that your scattershield was checked for center run-out using a dial gauge. This will also cause wobble/chatter if not set properly, and possibly damage your trans.