Think about the last time you had to crawl under the dash of your Street Stock race car to troubleshoot the electrics. Was it neat and clean, a place where you could easily find just what you wanted-and little else?
Or did it look like someone crammed it full of plastic-coated, colored pasta, with wires running in every direction and your being unsure of which ones went where . . . and why some made sparks and others didn't? We thought so.
There are Street Stock cars running today, probably at your local track, on which drivers simply use a pair of dykes to snip off anything coming through the firewall they don't want, and leave a wiring rat's nest of trouble under the dash. They run the risk of turning a minor electrical problem into a major meltdown.
Because the number of electrical circuits required is limited, the basic wiring on something like a Street Stock or Sportsman isn't difficult, and it doesn't have to be expensive. All it takes is a bit of time, thought, and attention to detail, just like any job that is done right.
Getting Started
Dennis Overholser, vice president of product development and technical services for Painless Performance Products, recommends you launch a new wiring job by getting rid of the old stuff. Painless makes wiring harnesses for street and race cars and sells the parts through local retailers for do-it-yourselfers to build their own.
Overholser says to begin your wiring project by pulling out the entire original wiring harness-every piece of it. "What's there is probably old and brittle, and with all the bumping, banging, and rubbing, you are likely to end up with a hole in it and have it short out," he says.
According to Overholser, everything you need to do a race car wiring job right should cost under $200. Here's what he recommends:
1. Move the Battery
If the rules allow, move the battery to the trunk. It helps balance the weight and gives you more room to work under the hood. Build or buy a strong battery box (see reference to bumping, banging, and rubbing under "Getting Started") and anchor it securely.
"For wiring the battery, I use a minimum one-gauge cable," Overholser says. "Don't get the cheap stuff with only a dozen wiring strands in it. Buy the finest cable you can find to get as much power as you can to the starter motor." Overholser says a good source for high-quality, fine-strand wire is welding supply shops.
"Run both the positive and negative cables all the way up to the engine," he recommends. "Don't skimp and just run the negative line to the framerail in the back of the car."
2. Install a Kill Switch
You'll have to decide-sometimes based on the rules of whatever group you are racing with-if the master kill switch needs to be installed on the positive or negative cable. The sanctioning body also will dictate where the master switch must be located. Some want it to be reached by a belted-in driver; others insist it be within reach of track safety personnel. Extension handles are available to do both.
While the positive cable runs to the starter motor, the negative side should be anchored directly to the engine block.
3. Protect Wiring With Grommets
"Every place a wire goes through the firewall or a framerail, it has to be protected with a grommet," says Overholser. "That's something you simply can't do without."
4. Use Fuses on Circuits
Most Street Stock cars won't carry many gauges. Most racers rely on a tachometer, oil and water pressure gauges, and an oil pressure warning light. Switches are usually limited to an off-on switch, and a push-button for the starter motor.
Overholser recommends these circuits be fused, using a high-quality fuse panel that can resist the jostling inside a car. "There are a lot of nice fuse holders out there," he says. "Look for one that is waterproof. One source for them is a boating supply house that specializes in severe duty applications.