763 vs 765 vs tilton cerametallic need advise.

Kopplingar, drivaxlar & växellådor
HenrikGM
För mycket laddtryck
Inlägg: 284
Blev medlem: sön aug 27, 2006 6:17 pm
Ort: Denmark
Kontakt:

763 vs 765 vs tilton cerametallic need advise.

Inlägg av HenrikGM »

Hi all ;-)

Have this 245 16v that i have gotten serious problems with.
Car is giving 563bhp, 683Nm with a garrett 60mm turbo from a scania bus, 8,8liter engine i believe it was. Just about everything was built from reworked stock parts.

Started with a 6speed M5 E39 gearbox on a sachs 763 plate with a kl racing 6puck unsprung disc. It worked nicely at lower power, but as the start got more an more fast, power went up, shifting started to deteriorate badly, ultimately ending with ruining the syncros.

Swapped gearbox to 530D, still on kl racing 6puck and 763. Rechecked for maximum clamping pressure and reshimmed to optimum clamp load.
Again, at low power runs, everything shifted nicely and fast. Once i started adding power and harder launches, the gearbox quickly resisted shifting severely. Low power shifting remained ok.
I noticed that especially the 2-3 shift depended alot on how hard the car was launched. A brutal launch in second doing a 60foot at 1,77sek would guarantee an impossible 2-3 shift. Waiting 3seconds and the gear would slip nicely in. Obviously not very streetrace friendly.

I am thinking this happens:
During launch, the clutch slips and warps something due to the thermal input, and prevents med from making the next gearshift.
Am i completely off track?

Reading topic after topic inhere, i see some are using the tilton 3 disc and converting it to 2 disc cerametallic "rally" type clutch.
We spoke with a Tilton representive some years ago, and he warns against slipping such a clutch, because it warps easily in a drag/streetrace application, leaving the clutch useless. Do the Tilton guys inhere see this problem on a 2nd gear launch?

He actually recommended to find a large chuncky conventional disc, to absorb heat instead of a multi disc setup.

What clutch setup would be a successfull setup, for a heavy 245turbo running upwards of 600bhp/700Nm and allow a fast shift still?