posi trak or limited slip

[DC COBRA]

bullseyeprec
I ordered my car with the limited slip rear-end, boyh tires never fail to spin or pull evenly. When I looked at the BDR cars, the demo I jacked up and spun the rear tires, turned liked an open rear-end, one tire going one way , the other one going opposite way. Really that was the deciding factor on me buying the car. Paid for the upgrade of limited slip and got it. I have done quite a bit of reseach on the BMW rear-end, know what is available, specs and so forth. I have talked to several road racers who run the base style rear-end that BDR uses in their BMW's, those rear-ends arereally pretty nice pieces. They are considerably stronger than what I thought they would be. The racers I talked to commented that they never heard of any body breaking one. BMW offers their limited slips in different degrees of lock-up breakaway. Factory ones are 25-35%. performance rebuilds will get you about45-50%, racing versions will get you about 75%, not recommended for the street. I ordered a new gearset with a 50% lockup, I'm going with 3.73 gears, they have quite a few choices. I presently have a stock 3.15 ratio with limited slip and at 6000 rpms in second gear with a Tremec TKO it will do 100 mph, I don't like that kind of speed capability. I like the car to be gear lowered, more squirrely, although it will break the tires loose in third gear roll on sometimes. I don't know what gears you are pulling, but I might be interested in selling my differential once I get my new diff in. One thing I like about the BMW rear diffs, they are easy to change , takes about 1 to 1.5 hours to do. There is nothing to leak out , they are pretty much sealed, pretty simple job.

DON