Torcs version: 1.3.1
OS: Debian sid
The car runs a little faster after you set Control Configuration such as speed limiter key.
Comment out a line in /home/user/.torcs/drivers/human/preferences.xml which is under "Preferences" - "Drivers" - "1", and restart the game and the car runs at normal speed.
It seems that the "clutch" parameter is tweaking the car acceleration coefficient somehow.