i play fox cars and try my best!

i am fairly new and thought i was doing some good corners etc but never near the leaders. recently i viewed 'in car' with leaders and realised that i have a limiter on my speed and they do not? how do i change this?

i.e. they can make 145 mph but i phisically cannot because a red light comes on on gear change. they have higher speeds each gear. i just cant see in the car setup where that is to change?

adrian. thanks in advance for advice.