915 in a 964 RS - Why???

[Kroggers]

OK, I need some guidance here. I today came by a fellow 911 owner who informed me that he had a 915 Freisinger box installed in his 964 RS 3.8? My first thought was why would you want a 915 in a 964, but before going any further I thought i would ask all you experts out there. Is there any reason to go to a 915 in a 964 even if it is apparently a Freisinger box????

[Steve@Rennsport]

I'd be curious to see how they did it,....

Mounting a 915 in a 964 would be a challenge since they mount totally different in these chassis' and thats a LOT of fabrication for zero gain.

[shahram]

well, weight could be a reason. 915 is as far as I know approx 50-60 LBs lighther than a 950.

[JeremyD]

and much shorter - you could probably move the engine foward a few inches for better weight distribution

[Jack Olsen]

One possibility is that the owner might have a pre-964 car that's been built to something like (or even better than) the specs of a 964 RS. Lots of race cars get updated body work for drag/aero advantages, while starting with an earlier tub to save on weight. In some cases, they're built to race as one particular model, in spite of the fact that their VIN is something else.

Of course, it could be someone who thought it was worthwhile to retrofit a slightly lighter race transaxle in a 964 RS, too.

[Rodsrsr]

I'd have to agree with Jack. Its probably an early tub. If what you saw was indeed a true RSR 3.8, I seriously doubt anyone would do anything to hack it.

[RarlyL8]

What is a "Freisinger" box?

[Geary]

All it means is that it was previously owned by Manfred Freisinger. As Manfred sells a lot of OE special ratio 915 gears, it is probably properly regeared for the track.