Whats the MAX RWHP and RWTQ can a stock A4 tranny with a 3.15 rearend take before it breaks? I have 440 RWHP and 410 RWTQ now. I would like to bump it up a bit, but just want to know if the T & R will take much more. The car almost never see either track.

Since stock transmissions can break and so can modified ones, I'm not sure that can be answered properly. Obviously, a built trans and rear end with quality high performance components has a better capability to cope with extra horsepower though.

IIRC the "fatal" limit on the 4L60E/4L65E/4L70E is somewhere around 800 HP. In a truck it would be less since much higher mass is involved. Stock trucks seem to kill stock 4L60E/4L65/4L70E's much quicker than Vettes.

Whats the MAX RWHP and RWTQ can a stock A4 tranny with a 3.15 rearend take before it breaks? I have 440 RWHP and 410 RWTQ now. I would like to bump it up a bit, but just want to know if the T & R will take much more. The car almost never see either track.
i would think you are pretty close now on the stock trans the differential probaly has some left

With a rolling start, you should have lots of room. IF your looking to smoke the tires, that's where all the trouble begins, one reason why most racers race from approx 20mph roll, except 1/4 mile track racers who always BREAK stuff.:duel:

rolling starts are much easier on the drivetrain..high rpm launches from a dead stop will show you whats weak real quick.!