I was running two different size 275/35/18 & 285/35/18 rs3 at the rear with Geared Quaife LSD. I know it's stupid, but i totaled my old Z, just bought another, dont want to spend money on the tires for the remaining 2-3 events, and then store them in the living room. so I put the 2 wheels were on the same side of the totaled z (the other size are damaged) to the rear of the new Z.

I took the car to autox last and this weekend, and noticed the tail tended to slide if I put on gas in the turn (gentle throttle), and once the car is sliding, it's almost unnecessary to recovery, even the guy did good in national event.

I was wondering is it mess up the diff even just 1.1% difference in the tire diameter (tire pressures are the same)? and the slide tendency is result of the size? Thanks.

 

I think you've answered your own question.

 

You have a torque biasing differential, and different levels of torque on each side of it.

Yeah, i'm going to go ahead and say bad plan.

 

Absolutely, a bad plan. It won't be good for the Quaife and why train yourself to drive with such a cockeyed setup?