Nick mentioned to me that there were two option LSDs in the 944 series. The normal "audi" based unit with option code 220 (known as the 40% lockup). There was also another LSD option code (don't know name) where Porsche tweaked the 40% LSD to make an 80% lockup LSD. My own local mechanic thought I was crazy when I mentioned it and he can't find a code for it. Does anyone have any information on it. IIRC Niel's car has this uber rare LSD.

jaje wrote:


Could be the 944 Turbo S LSD with added shim plates. I have turbo S street car and I believe those LSD were different from teh early ones. The shimming is not factory, but due to the design of the unit it can be done by a competant motorsports shop.

Either way you can buy off the shelf a guard LSD that will do the same thing. They are not cheap, but available.

The units Nick refers to have an oval hole, instead of a round one, I believe, but I'm not sure of where they come from. I get no wheelspin from my 40% LSD, and I'm not sure the understeer, and increased friction losses make the added stability under braking worth it at our power outputs. I haven't driven one back to back to be able to know for sure. It would likely require a bit different setup, any any case.

I spoke with Nick and he searched forever for this info and wound up talking with a Porsche engineer in Germany about this. The inside of the transfer case is stamped a different # (not the outside) - the housing is shaved with an oval hole to allow more space for fluid and different packing of the differential. These were very uncommon and Nick said he saw one 944 with the option 221 code (doesn't shop up on Porsche normal option list) and it had the 80% lockup differential.