Dirt Late Model driver Chris...
Dirt Late Model driver Chris Hargett says the ability to shut off the brakes on the right front wheel can be helpful when the track is muddy (hot laps) or your car is pushing badly.
One of the great challenges of racing on dirt is the extreme variability of the racing surface. We're not talking about changes from one month to the next, or even week to week. The changes that the typical dirt track goes through from hot laps until the feature can feel worlds apart for the driver. Because of this, it's the intelligent race team that can consistently predict how the track will change and adjust for the changes that will almost always have the greatest success.
The key for many teams is to build in as many adjustment options as possible-both large and small. One large adjustment option is to install a brake shutoff switch in your car (they're also often called line locks). The purpose of the brake shutoff isn't to cut off the brakes completely; rather, it is connected to the brake plumbing so that it disables just the braking to the right-front wheel. When the driver presses the brake pedal, the left-front wheel grabs and helps the car turn. This can be especially helpful on a wet track or when the setup on the car is too tight.
TCI has recently released a brake shutoff designed specifically for circle track racing. Previously, many racers had to use line locks designed for drag racing that are larger and more complex. TCI says this unit is manufactured for minimum size and weight. It's constructed from aluminum and is waterproof, so there are no worries of damaging the unit when using a pressure washer to clean your car after a Saturday night of racing. This unit's small size and simple operation also make it easy to conceal if you want to keep its existence on your car to yourself.
Installing a brake shutoff such as this is relatively straightforward. For this article, we followed along as Dirt Late Model racer Chris Hargett installed TCI's Brake Shut-Off. The best braking system for race cars is to use separate master cylinders to operate the front and rear brakes. So if one fails, you still have some brakes. On the system controlling the front brakes, install the brake shutoff after the brake lines split so that the shutoff affects only the circuit for the right-front brake caliper. The shutoff is labeled with "Master" on one side and "Brake" on the other and includes connections for a standard double-flared solid brake line. Obviously, the line from the master cylinder connects to the side labeled "Master" and the line exiting the shutoff and connecting to the right-front brake caliper is labeled "Brake." Where you mount the shutoff is up to you, but mounting it on the firewall is usually the simplest solution.
Hargett chose to mount the...
Hargett chose to mount the unit on the outside of the driver's compartment. Notice the "T" junction directly above it. This splits the braking circuits to the left-front and right-front wheels. Line pressure enters the solenoid on the side labeled "Master" and exits to the right-front brake caliper on the side labeled "Brake."
TCI's Electric Brake Shut-Off...
TCI's Electric Brake Shut-Off is an electric solenoid designed specifically for circle track racing. For example, its compact design means it can be installed just about anywhere on a race car, and it is waterproof, so hosing it down after a hard night of dirt racing won't cause any problems.
Here's a shot of the layout...
Here's a shot of the layout of Hargett's newest Late Model. The toggle switch for the brake shutoff is on the right between the ignition controls (far right) and tach controller. A cover for the switch is extremely important so that you do not accidentally trigger the system.
Once the plumbing is in place, turn your attention to the electrical component of the install. The shutoff is an electric solenoid, but it requires only a single amp of current so it won't be a drain on the electrical system. Two wires protrude from the aluminum body: The black wire is the ground and should be attached securely to a reliable ground on your race car (either the engine block or a section of the chassis that has the paint or powdercoat scraped away so it can connect directly to bare metal). The red wire connects to the toggle switch. Hargett recommends using a high-quality toggle and definitely one that features a protective flip-up cover so the switch cannot accidentally be flipped.
"You want the switch within easy reach, so that makes the cover important so you don't accidentally hit it," says Hargett. "Shutting off, or turning back on the right-front brake for that matter, makes a big change in the way a race car handles, and you want to make sure it doesn't happen with you unaware."
Finally, you can wire the switch to your power source-it's that simple. Even with minimum power, TCI says the solenoid is capable of 3,000 psi of pressure, so you cannot overpower it by hard braking. Also, it's instant-on, so you can flip it on right before turn entry and be safe.