I see what spyper saying about doing a standstill with engine not revving past 2500rpm.
If you simply apply brake, then dump accelerator, the same happens in my VS Calais.
This is a good way to burn your fluid.
As I understand it, thats the nature of stock standard autos with fairly stock V6's.(VS - VZ anyway)
Think about it; in an auto, your driving force is transferred through fluid. at low rpm, there is a lot of give in fluid. you can rev your engine, but this will not necessarily involve movement of the wheels. as engine speed increases, torque converter tries to 'lock up' so to speak, which puts load on engine. Stock V6 will not rev over 2500rpm because engine is not powerful enough to rev any higher in this situation....
In a Manual your driving force is transferred through clutch plates, which when locked up theres no give, either your engine stops or your wheels move.
I think you just have to use a little style when doing your burnout; i.e don't fully apply brake, get a bit of roll, hit the brakes about 50%, transfer weight to front of car, then she should be away...