trouble after the track

[xzaero0]

So I have had this grinding noise comming from the rear of my car for awhile now. I took it to the track a few times and made a few passes here and there this summer it ran just fine. When I would launch the car would just sit back in the rear and the hood would come up and down the track I would go, but the last time I went to the track it was different it just burned the tires off. The car would just spin the tires all the way into 2nd and I would have to let off of it cause it would start to go sideways in the lane. After that the car pulls some to the right, and it feels like it shimmies a little, and rides rougher and the grinding noise is as loud as the exhaust. At first I thought that I twisted the frame but it all looks straight, also I dont see me twisting the frame launching at 1000 RPM and on street tires. A mechanic friend of mine looked it over and says that he thinks that I broke something in the carriage / destroyed my limited slip. That would account for all the problems that I am having. I am looking into a new rear end since the stock 10 bolt is not going to hold up, even if up graded. Has anyone else had these problems, and does the diagnosis sound right?

[JHayesLS1]

If your M6 get a new rear with a 4.10 differential. Then go back to the track and give it hell!

[xzaero0]

If your M6 get a new rear with a 4.10 differential. Then go back to the track and give it hell!

Its an A4.

[sunsetorangess]

As far as you twisting your frame, launching at 1g rpm will not bend your frame, Sounds like Your 10 bolt has taken a dump on ya. I would go with some 3.73's and a 12 bolt, you wont have to worry about your rear end again. Our stock rear's are just iffy, sometimes they hold up for a while and some times they just take a shit on ya.
J

[xzaero0]

As far as you twisting your frame, launching at 1g rpm will not bend your frame, Sounds like Your 10 bolt has taken a dump on ya. I would go with some 3.73's and a 12 bolt, you wont have to worry about your rear end again. Our stock rear's are just iffy, sometimes they hold up for a while and some times they just take a shit on ya.
J

Until recently it always seemed to just hook up. One day I had a friend behind me and I got on it about 3/4 throttle and the tires lit up and the rear end tried to run out from under it. Scarred the hell out of me, it never broke free like that before. Of course that was before the last trip to the track so I think that the damage was done before that. Before that It had its share of what I wouldnt call "hard launches" but down shifting from a 10-40mph roll couldnt have been easy on the frame. Also the car has 111,000 miles on it. I got my sfc ordered, and I am still going to have it checked out before getting them weleded in...just incase.