Stock Car Technology - Data Acquisition

During testing, try mounting the camcorder inside the car so it will show where the car is on the track in relation to specific landmarks. While testing, have someone time and record each lap. Find the fastest lap and then go through the videotape to see how you drove it. Then see if you can do it again. Once you are consistently running the fast times, begin timing laps in segments and concentrate on individual corners, working to improve each one until your times drop again.

"You have to concentrate on running the perfect line," says Lewis. "During testing you shouldn't be driving around problems with the car, you should be solving them. Once you get the car right, then you can begin trying things."

Think you are a late braker who is on the gas all the time? Install a red light on the dash where the video recorder can see both the light and the track. Wire the bulb into the brake circuit, using either the factory-provided brake light switch or a pressure-activated switch in the brake line. You may be surprised at how early-and how long-you are on the brake pedal. Most drivers aren't nearly as brave as they think ... or tell their crew chief. Using a factory switch, it costs about $2 to add the light to most cars.

You can mount a tachometer next to the red brake light to get a fairly accurate picture of where a driver gets on and off the throttle. It is also a way to check how fast the engine is turning at different points on the track, which could indicate the need for a different rearend ratio.

In-car lap timers, such as the Hot Lap system, are about $270. They use a light beam to trigger a sensor mounted on the rollcage and pointed to the outside of the track. A battery-powered trackside transmitter sends a signal to the in-car receiver each time the car passes it. A dashboard readout instantly gives the driver the last lap time, accurate to 1/100th of a second.

By mounting the readout where the video camera can also see it, you can create a visual record of every lap with how you drove it and how long it took. If you are on a track with a lot of landmarks, you can use them to time the car through portions of the track and come up with segment times.

"You can really work on a corner to get it just right," Lewis says. "Sometimes we look for the best line that will carry speed and still save the tires. Finding it sometimes means changing the turn-in point or where I get on the gas by just a little bit. We also use the timer to help us find the perfect qualifying line, the one lap where you just go out and don't worry about the tires."

Lewis says drivers can learn many things from a lap timer. "You have to have some idea of what you are doing to begin with, but that just takes time and thought," he says. "But you have to know how the car works before you know what to change."

Many drivers buy too much data acquisition, says Dave Scaler, owner of Advantage Motorsports. "They end up paying for things they don't need and will never use. And then they get so much data they don't ever begin to approach figuring out what they have, never mind what it means and how to use it."

Scaler's company builds a basic data acquisition system that costs less than a set of race tires. For under $600 the basic Advantage system can gather data on wheel and engine speeds. "If you really think about it, for most circle track applications that's all you need at the amateur level," Scaler says. "That tells you where the car was fast."

Scaler uses the example of a driver who turns laps in the low 19-second range. "His laps are all very close to one another and his crew chief brags about how consistent he is," Scaler says. "But on the first lap he was fast in Turn 1 and on the next lap he was fast in 3. The key is to find out why he was fast in 1 and why he was fast in 3 and make him turn laps where he is fast in both of them."