burnout dominator multiplayer speed up problem

[fakeman]

Hi,I'm using multi-instance on same pc to play burnout dominator multiplayer mode.
Ends up with the sped up problem, the car runs like rocket .

Tested following method
1.multi-instance on same pc, adhoc connect
2.using sandboxie to open multi-instance , adhoc connect
All methods lead to sped up problem.
No speed problem with other racing game.