Driver Skills vs. Acquired Data

How to Improve Steering Control

One of the first items to consider with steering is whether you are inoffense or defense mode. This is a clear concept in other sports, but itis often overlooked in racing. On the defense side of the game, ifsomeone drives across your line entering a turn, an adjustment must bemade.

Another example of defense is when you are "off-line," fighting forposition. The lap times nearly always suffer when driving in defensemode. Offense mode occurs when you are clear of traffic and you candrive the fastest line around the racetrack. The steering controldiscussed here will only address the offense mode.

Conversations about driving often address the "line" (the path you wantthe car to travel), but never how to manipulate the steering wheel toachieve a given line. Consequently, some drivers are not aware they arecausing a handling problem (or the difficulty maintaining a desiredline) because of their steering skills.

Graph 5 is an example of a driver who mistimes the steering for thecorners. The steering trace for both corners has a leading spike ratherthan a rounded plateau. The leading spike is where the driver is tryingto get to the bottom of the track.

In this case, the race car gets to the bottom quickly, and the drivermust reduce the steering for the remainder of the turn or end up in theinfield. The steering input for turns 3 and 4 shows the timing wasmistimed badly enough on this lap; a second big "cut" on the steeringwheel was necessary to finish the corner.

Sometimes, drivers are not aware of what their hands are doing or howthey are responding to the feel in the steering wheel. Interestinglyenough, not all drivers respond the same for a given feel in the wheel.

Some drivers appear to be force oriented (increasing/decreasing wheelangle to maintain a specific torque on the wheel). Other drivers aredisplacement oriented, turning the wheel to a specific angle while beingunaware of the speed at which the wheel was turned. Here, again, iswhere data acquisition can do wonders in developing steering skills.

An example of force responding to wheel feel can be seen in Graph 6.Here, the data shows what is often called "sawing on the wheel." You cansee a big overall hump on the graph for each turn, but there are lots ofwiggles in the line, indicating a back-and-forth motion on the steeringwheel. Graph 7 shows the same driver after the "sawing" was brought tohis attention via the data acquisition. Here, you notice the trace ismuch smoother.

Also, when the driver made a conscious effort to change the steeringinput, the car settled down and the lap time went from 21.129 in thefirst example to 20.846 in this example.

While smoothing out your steering motion sounds quite easy, in reality,it is very hard to do. The previous examples are from a full-timeprofessional driver on a half-mile racetrack. Graph 8 is a weekenddriver (with several championships to his credit) on a half-mile track.Notice here there are fairly big jags in the steering trace.

Another example of a weekend racer is displayed in Graph 9. This, too,is a champion racer with many pole positions and wins to his credit.Notice this steering trace is fairly jagged, too. As mentioned in the300 Percent concept, a track champion typically has better skills than aracer in the middle or back of the pack, but you can see a full-timeprofessional racer has better skills, yet.

How to Improve Braking Control

Braking control tends to be more difficult than throttle or steeringcontrol. One of the reasons braking is so difficult is there areactually two brakes on a race car. Everybody is aware of the brakepedal; however, the engine is also a brake.

The total slowing of the race car can be a result of the engine brakeand/or friction brakes. It's the blending of engine brake and foot brakethat makes this skill more challenging and the reason "left foot"braking typically yields the best results.

Most drivers are unaware of how they use the brake pedal. Some may beable to identify using a large amount of pedal force for a shortduration or a lower pedal force for a longer duration, but beyond thatthey are typically unsure of what their feet are doing. Just likethrottle and steering control, the minutia of highly skilled brakingseldom come naturally and must be developed.

Pressing the pedal to reach the maximum force is an important skill. Toillustrate this point, examine Graph 10. Here, you will see a very quickand smooth increase in force to a peak value. Also, the peak brakingforce for both ends of the racetrack are virtually the same. This is askill many weekend drivers lack (this graph is from a full-time pro).Oftentimes, you will find brake force varies from lap to lap and inevery turn. The ability to repeat the same force is paramount inimproving lap times and solving setup conditions with your chassis.

Another braking skill is the release. In Graph 10, you can see that thedriver had a steady and uniform release of the brake. However, in Graph11, this driver did not release the brakes smoothly, which many driversdo without realizing what they have done. This can lead to body rockingor a yaw oscillation (i.e., bad handling). Typically, chassis setupreceives the blame for this condition rather than the real source--thedriver!

Again, combining brake-pedal motion with the throttle motion is key tomastering braking skills. You can slow down by simply taking your footoff the throttle, or slow down faster by pressing the brake pedal. Bothactions work together for the total slowing, and data acquisition can beused to measure the overall result, too.

One concept used to measure overall slowing is sometimes called"Deceleration G (force) Time Integral" (DGTI for short). The red traceon Graph 12 can be used to illustrate the DGTI concept. The foundationof this concept is the total slowing can be compared to a given force(say 1 g) for a specific amount of time.

In Graph 12, there is a red box just to the left of the crosshairs inthe middle of the screen. The DGTI for this turn is 2.097 (or theequivalent of slowing down at 1 g for 2.097 seconds). Notice that eventhough the brake pedal was released (blue trace), the red line is stillclimbing (increasing the DGTI). This is due to the lack of throttle(engine braking--green trace).

Even partial throttle can slow your race car! Once the throttle headsback toward 100 percent, the red line levels off for the final value ofdeceleration. To further illustrate this point, in Turns 3 and 4, thedriver used no brake and only lifted the throttle. Notice that the redtrace climbs in this condition, too.

The DGTI may be a little difficult to comprehend at first, but once youget the idea, it is an incredibly powerful tool for developing brakingskills and improving lap times.

Summary

In the past, some drivers were said to be naturals. Some excelled intheir racing career and some never made it out of the local level. Itwas also believed that a struggling driver just needed more seat time toimprove. However, practice doesn't make perfect, only perfect practicemakes perfect. Otherwise, just practicing may reinforce bad habits andgood race driving skills may never be developed.

Now, with the introduction of affordable data acquisition, even localracers can develop the skills necessary to win or move up the racingladder. You have now been exposed to some specific race driving skillsthat should be goals for your driver to try to achieve in the seat. Thebonus to approaching racing performance in this fashion is you maydiscover there is nothing wrong with your race car's setup/power or thatmany of your setup/power problems disappear with the development of gooddriving skills.