Roll Control Kits & Line Lock Switches

Installing a line lock or roll control on your automatic or manual transmission-equipped vehicle improves starting line launches as it controls tire roll and holds the vehicle while you raise the engine rpms up to the peak power level. Once the line lock switch is released, the vehicle will leave the starting line quicker than using the "foot-brake launch" method.

Line lock kits allow you to hold the vehicle so you can spin the tires at special events. Participating car and truck shows allow safe operation of tire spinning to create burnout, doughnut, and tire smoke contests under controlled conditions and strict rules.

Roll control, which is also called and referred to as a "stage control", "line lock", "anti-roll", "launch control", and "rollstop" kit, is an aftermarket add-on system that is used for the purpose of locking the wheels opposite of the drive wheels by holding brake pressure. For example, line lock kits can be plumbed for locking the front wheels for rear-wheel drive vehicles or the rear wheels for front-wheel drive vehicles. This helps hold the vehicle in place while the throttle is increased and the transmission is in gear at the drag racing starting line. To activate the line lock system, the brake pedal is depressed firmly and the line lock switch or button is activated. This energizes the line lock solenoid and holds the brake fluid between it and the brakes, locking the wheels. The foot is then taken off the brake pedal and the throttle is then increased to raise the rpms to the peak power level, which improves take off acceleration (provided the drive tires have traction). Roll control / line lock is beneficial to manual transmission racing, helping the driver use both feet for the clutch and gas pedals while controlling the brakes and vehicle movement by hand. When the driver decides to leave the starting line, the roll control switch is released. This deactivates the solenoid and releases brake pressure, allowing the vehicle to leave the starting line. Roll control systems can also be used at special car and truck events that host "tire smoke", "burnout", and "doughnut" contests, which helps hold the vehicle while the tires spin.

The directions to mount a roll control or line lock kit vary depending on the kit manufacturer, the year, make, and model of the vehicle, the type of brake master cylinder used (single or dual), and which brakes you want locked. Following the manufacturer's instructions is important for successful installation and operation. In most applications, the solenoid is installed in the main line from the master cylinder that leads to the rear or front brake lines. The solenoid wiring is then connected to a roll control switch or button that is mounted on either the steering wheel, shifter, or dash for easy access. An indicator light is also installed, typically with a wire harness to the dash, to let the driver know that the system is active.

The roll control or line lock kit cannot be used as a parking brake or emergency brake (which are mechanical). The electrical solenoid isn't designed to stay energized for long periods as it will get hot and then fail. The correct way to hydraulically lock the brakes for parking or holding a vehicle is with a hydraulic brake lock. This "hill holder" component functions much like a line lock kit, but with a mechanical button and will not overheat and fail due to being electrically activated.

There are different terms and names used to describe the system that locks the brakes. These systems are advertised as "line lock", "roll control kit", "stage control", "line lock", "anti-roll", "launch control", and "rollstop". There is not a difference between how they function; only the name they are given.

When you need starting line and roll control for your vehicle, a line lock or roll control kit will give you the ability to achieve those quick launches off the starting line during drag racing. This will help you reach the finish line first at the next event. Browse our full line of roll control and line lock switch options, including our very own JEGS line lock kits today.