Limited slip rates

#1

Is increasing the lockup percentage of the factory LSD allowed? I would hope so since welded (i.e. 100% lockup) is allowed.

#2

IIRC, it is not (don’t shoot the messenger :slight_smile: ). I think that was discussed while Yahoo group existed. If no one else replays with the certain answer you can search archived Y! group postings (see Archive section on the main Forum page).
Igor

#3

Nope:

9.3.11. Differential
9.3.11.1. The final drive ratio for each eligible car is specified
9.3.11.2. Factory limited slip differentials are permitted.
9.3.11.3. Welding to create a "locked" differential is permitted.
9.3.11.4. Finned, larger capacity differential covers may
9.3.11.5. Differential lubricant may be substituted.

Doesn’t specifically allow you to do it so therefore you can’t.

Ric

#4

Messing with LSD rates gets pretty expensive and I’m sure that’s the reason for this rule.

#5

I don’t see it that way. Given many factory LSDs are pretty old, we’re all going to need to go through a rebuild at some point and upping the lockup rate is pretty cheap to do at that point.

#6

I’m probably going to end up running an open diff. I don’t think any of these cars really need it.

#7

robweenerpi wrote:

My first race weekend on my car last year convinced me that the LSD is required. My base car/non LSD was spinning the inside rear tire so badly that it was no fun on the track.

My good friend Alex had a 3.73 LSD in his garage 50 miles away so we swapped it Saturday afternoon. Thanks Steve K and David H!!!

After the swap, it was a completely different car. And my laps time dropped several seconds I’m sure.

Carter