At the timestamp in this video https://youtu.be/Ai3cnc-77ZE?t=355, Bill Jenkins is holding down a switch on the shifter and when he launches the car he also releases the switch. What is that switch for?
Add a comment
|
1 Answer
The button would be for a line lock.
A line lock will hold the front brakes until released. To make it work, the driver pumps up the brakes until they are hard, then presses the button. This engages a solenoid which keeps the front brakes locked up, but allows the rear brakes to release. This allows the driver to load up the drivetrain in preparation for vehicle launch when lining up at the lights. When the driver wants to go, they release the button and this releases the brakes. This in effect, gives the driver a third foot, which allows one foot to be on the clutch pedal and the other foot to be on the gas pedal while still maintaining the brakes.
If the vehicle was an automatic transmission (what is show in the video is a stick or manual shift transmission) it could also be what is called a trans brake. A trans brake works by putting the transmission into drive and reverse at the same time. This allows the engine to be revved up to the point of the stall speed of the torque converter. Once released, the transmission releases the reverse band allowing all of the built up power to be transmitted. Again, what Grumpy Jenkins is driving is a standard shift, so this would not be why he's pressing the button.
