What would a ceramic clutch do when i downshift hard that my spring centered sachs ca

[BReyes]

What would a ceramic clutch do when i downshift hard that my spring centered sachs can't do. With my Sachs (on G50) -it's the only time I smell the clutch after shifting and I don't like thinking what that would do after a few weekends on the track.

Thank You,

[Grady Clay]

Bernard,

I don’t think I can exactly answer your question but here is some input.

First, using your clutch to decelerate your car in place of using the brakes is an expensive and short lived option. The brakes are for taking the kinetic energy of the mass of the car at speed and converting it to heat energy. I recall a Christophorus article in ’69 touting the fact that “S” brakes could dissipate 800 HP each. I don’t know the figures for the current ceramic brakes. Even the best clutch is below this by several orders of magnitude.

Brakes are located out in the air stream to transfer the heat to the air. The cutch disc is sandwiched between the pressure plate and the flywheel. Additionally it is enclosed inside the transmission bell housing. Not much heat transfer there without exceedingly high temperatures damaging the disc.

In normal operation you use the clutch to disconnect the engine from the wheels so the transmission synchronizing parts can match the rotational speed of gears preventing clashing. For street cars no one uses non-syncro dog-clutch gears since WWII. Yes, they are used on race cars.

The key for proper clutch operation is to match the RPM at gear changes, thereby minimizing clutch wear. This is true for every clutch. Timing is everything. Street clutches are designed with a couple of important features: The disc has a spring between the two friction surfaces. This allows for progressive engagement. Many race-only discs don’t have this feature and are very prone to “judder.” The other feature is a compliant center connecting the disc to the transmission input shaft. This reduces the shock on all the components. Many race discs don’t have this feature and produce more wear on expensive transmission parts.

All that said, there are some very specialized circumstances where skilled race drivers use the clutch to decelerate the car by changing it’s handling. Trailing throttle and “dumping the clutch” will induce over-steer. In unusual circumstances that might be useful.

Another situation where abuse of your clutch is useful is with fastest acceleration starts from a standstill. Remember, drag racers replace their clutch between runs. You can do that also – just a lot more expensive.

Best,
Grady

[BReyes]

Yes that is right. The front pads hardly wear. I have a brand new box and haven't put them in . Did the rears couple months ago.

Noticed, while practicing my cadence braking, that I have been very keen to prevent any use of the clutch with undue costs. And I even have that new box of front pads that have been sitting there (Did the back pads over the holidays). Admit did let the clutch run her up a couple thou prms, in a lil tip toe slow down and um outta there.

Where did I put that Vic Elford book?