Hi,

I was wondering which lsd transmission is legal for
spec. Can it be out of any car (924S,944,944S,944 Turbo)
or is it limited? Does the transmission work between
early and late cars? What is the dream one ...
I think at the 1988 (short 5th) lsd is it?

Getting closer and closer...

Thanks

Sid

The 944S, 944S2 and 944 Turbo all use different grear ratios in the tranny. So they are not legal. However if you start digging into the tranny some individual gear pairs are legal. The Turbo's 5th grear for example is the same as the "Short 5th" we use in spec cars. The LSD unit in any of these cars is legal in 944 spec, but the ring and pinion from a 944 Turbo is not legal since the raitos are wrong. Now before youthing about an advantage all the 944 S2 and 944 Turbo final drives are tall than the legal ones. So put one in and teh car will go slower!

You can swap gearboxes from early and late cars. There are some mount changes you need to make and some issues with the speedo's. However race cars don't need speedos!

the factory LSD's seem to all be the same so the dream LSD would be the Guard LSD.

SvoChuck wrote:


...at over 2K + installation.

any '87-'88 924S trans would have the short 5th, and a few of them have LSD's. Otherwise, its not hard to install a short 5th in a regular MA LSD trans. Sid LSD are not essential in our cars. I didn't go any faster last year with an LSD at the same tracks than before I had an LSD, though the car was a bit easier to drive, and I was probably a bit more consistant. Our car don't make that much power to make this essential.

The cheapest option is to find a used LSD tranny for around $1K and just swap yours out if you find that you need LSD. Most tracks don't need LSD but having it couldn't hurt. Even the short 5th is not necessary but it all depends upon the track that you race most at. Here in Northern California like Infineon and Thunderhill, we don't need to shift into 5th gear. At Infineon, an LSD will help but at Thunderhill, it wouldn't make a difference.

I have run for years with an open diff. Track record at PIR is 1:12.6 using an LSD. My best is 1:12.86 with an open diff. How much difference does it make?

The LSD unit is great to have, but if you don't get one right away don't worry about it.

At PIR the short 5th is pretty much required. If you are at a track where you need to use 5th then you will want the short 5th. If your track keeps you in 4th then clearly 5th is not a big deal.