A JW Performance C4 transbrake valve body installed in your transmission gives you the option of drag racing in the electronics classes. In addition to providing the hard hitting launches that trans brake equipped C4 transmissions are known for, many racers find improved reaction times and more consistent elapsed times using this combination.
If you would like a further definition of what a C4 transbrake is and how a transmission brake works, please click: How does a C4 transbrake work.
If you are looking for a manual shift valve body but do not want a trans brake, please view our manual valve body products here.
JW Performance Transmissions, Inc. builds some of the best quality, quickest releasing, C4 transbrake valve bodies on the market. We offer their entire line of dependable, hard hitting transmission brakes. When using electronics like a delay box, you make the best use of them by using the delay box with a transbrake.
|Automatic Transmission Brand and Model||Transbrake Type||Part Number|
Ford Mercury C4 Transbrake 1970 and newer models
|Internal, Reverse pattern||
This is a complete replacement C4 transbrake valve body. This valve body is installed in place of the original stock valve body.
A) An automatic transmission transbrake is a modified or aftermarket valve body which puts the trans into first gear, and reverse gear at the same time. This is accomplished in part by supplying 12 volts to the valve body by a relay or solenoid. As long as power is supplied to the valve body the vehicle will not move. This allows the engine to be brought up to a higher rpm than what is possible when "foot brake" racing. When the brake is engaged, there is no torque being applied to the driveshaft, so the suspension is also in an unloaded state. When electrical current is removed from the brake, the reverse component of the trans is released, and torque is applied to the driveshaft very abruptly. This "hits" the tires harder, more like what a manual transmission car does when the clutch is released. Since the transbrake is controlled by applying an electrical current, it is also the preferred method of controlling when the car launches when using delay boxes and other modern drag race electronics.
A C4 transmission brake can be used in a street vehicle, but is most commonly used for serious drag racing.
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