are limited slip differentials or other locking diffs permitted in the sbox class.
i read the rules. doesnt seem to suggest they arent, but doesnt say they are either. seems like yo uhave to use a stock transmission and the title to the chapter says transmission/differential. was there a differential stock on the 99' stock transmission?

 

I may be wrong but I don't believe a LS diff was an option on the earlier Boxsters.

The rules also say something like if it's not specifically permitted it's not allowed...

 

None of the 2.5 Boxsters had an LSD optional... actually, none of the 986's had them. They are specifically NOT allowed in Boxster Spec.

 

Yep, not allowed. doesn't mean nobody has one unfortunately.

 

Not very many, if any, of our LSDs running spec Boxster. However my understanding is there's a bunch of Quaifes and TBDs out there because they are harder to detect than a real LSD.

 

[QUOTE=kcpaz;8271132]None of the 2.5 Boxsters had an LSD optional... actually, none of the 986's had them.QUOTE]

Okay, then what's this option...

M224 - Automatic Limited Slip Differential

From this list...

http://www.986online.com/cgi-bin/ASI...tioncodes.html

And if M224 is not LSD, then what is it? That option is listed on the 1999 Boxster that we just purchased last weekend.

 

My understanding is that the M224 option is an electroniclly controled version of a limited slip not a mechanical LSD. I believe that it is similar to the ABD (automatic brake differential) option on the 993.

 

Alright. I'm good with that. Hopefully that feature is somewhat useful in autocross

 

Correct, no LSD on the Boxsters. They had M224 which is ABD. What we would have wanted was the M220 Locking Differential option from the 996 1999MY, this was never available on the Boxster.

Codes from the 996:
M219 DIFFERENTIAL
M220 LOCKING DIFFERENTIAL 40 %
M222 TRACTION CONTROL SYSTEM
M224 AUTOMATIC LIMITED SLIP DIFFERENTIAL