brakeTorque kills fps after I updated unity from 4.0 to 4.1.5

Unity Engine
1

Hi. Anyone encountered this problem?
In 4.0 all was fine, but after I updated to 4.1.5 I got the problem. The fps goes from 60 to 3 when I press space bar (car script).
The problem is in line of code

wc.brakeTorque = handBrakePower;

And I need version 4.1.5 . I cant update to higher version.

2

up