mspiegle

if I understand correctly, having a GTS box would mean having the PSD, and having a PSD would implicate doing some other work. Is that true? I find the whole shot-peening of the gears pretty interesting. I've heard of the high-hp supra guys performing cryo treatments to their trannies, if I got a decently fresh GT box, i might consider that as well.

I think at this point, I would aim for a GT box when I fry my transmission. IIRC, someone else on this board has swapped a GT box into their earlier 928 with good results.

Apparently, my clutch isn't happy with 5k drops... the car hardly budged with the drag slicks. The clutch just spun from 4.5k until 6k when i let go. Should I be able to do this with a twin-disk clutch? Maybe mine is just tired and I need a new one.

slate blue

I'd say you clutch is a bit tired, on the PSD issue, yes you will need to address this otherwise you just have an open differential. Perhaps you could get a toque biasing diff made? I think that is what I will investigate. Marl Anderson told me he runs a bolt instead of the PSD slave cylinder. This would allow an adjustable amount of lockup to be dialed in. Which is certainly better than the upto 40% of the LSD. Also the psd has more clutch plates.

I don't know much about the cyro treatment, but some people swear about so, maybe worth investigating, can't see how it would hurt.

slate blue

928 Intl has a GT box according to their catalog, why don't you try and trade in your box before you blow it up, that way your change over cost wont be so much.

mspiegle

that's actually a pretty good idea since I need to change my torque tube as well.

I think once I get my daily driver working properly again, I can put the shark to rest for a while and do some part-swapping.

Would you happen to know if the '87+ pressure plate can replace the earlier twin-disk pressure plate? IIRC, it has more clamping force, but I am not familiar with the dimensions... might be too big.