Race Driving Fundamentals
by Lee Marks

Chapter 8

Late Apex              

As explained in

the fundamentals of race driving, taking a late apex enables you to extend the straight-away slightly, and thus pick up a fraction of a second, in reduced lap time. In the late apex you are not overly concerned about having the car set up in a precise position to accelerate out of the corner. That is because you use the late apex when the corner you are taking is followed by another or some circumstance.

Also, as explained in Chapter 7 on braking you must use the late apex to protect or to take a position. In this scenario, making a good lap time is secondary. Many drivers get hypnotized into taking the correct “line” and apex through corners of any type. They rely on superior horsepower or handling to pass competitors.

The famous formula one driver, Giles Vilanueve would take any line or apex to make a pass. He would never play follow the leader. Dale Earnhart is another who started in last place on the grid and just worked his way through a field.

It is as though they have a sixth sense of where to place their car to make a pass. The other drivers become intimidated by their confidence and “take no prisoners” driving style. Both of these drivers learned their skill in small tracks all over the North American continent. They would race anytime, anywhere.

Giles was infamous for practicing on the public streets to the point where no one would dare be a passenger with him, for fear for their life. Dale could be seen at many local small town races beating the under-classed locals, even when he was a national champion and making millions of dollars a year. These greats knew that they had to practice and practice to enable themselves to take unusual “lines” through corners in order to pass or hold off a pass. You do not have to go through the extremes that these guys did. Just pick out some corners and practice over and over until it becomes second nature to take any apex or line you deem necessary, with a split second decision.

To begin with find a straight leading to a corner. Freeway off and onramps work well. On a high speed straight before a corner you will brake your car to reduce your speed to a level where you can downshift a gear. It may be helpful to mark your speedometer or tachometer with nail polish to help you.

Here is how you find the exact speed or RPM level. Let us say that you have the car in 5th gear going down the straight and your speed is 55 mph and your tachometer says 2500 RPM. Change down to 4th gear and gently let out the clutch and watch the tachometer closely, the needle must not go beyond the red line reduce your speed to say 52 mph. This will automatically bring down the RPM as well. Then try that number.

Find the correct speed or RPM for the downshift of every gear and mark the dial gauge with a number and line. “Blip” the gas with heel and toe technique to bring up the speed of the main shaft on the transmission to make gear changes as smooth as butter.

Plus smooth downshifts do not unsettle the car as much either. Proceed to take the correct line through the corner to hit the late apex you have picked out. Also practice slow speed the same way and gear all the way down to first gear. You will know when you have made a good shift because there is little resistance in transmission.

Plus the car will not be so unsettled on freeway on ramps leading into a corner. Accelerate and when it is necessary to shift to a higher gear just keep your gas pedal to the floor while changing gears.

Drag racers do this regularly. The process involves holding the gas pedal to the floor and depressing the clutch and changing gears and then letting out the clutch in about 2 seconds flat! When it is done correctly, it goes very smoothly and it sounds like you are changing gears with this all the time during racing because of the wear and tear on the drive trim. But, you must be prepared to “pull out all of the stops” in order to pass or hold off a pass by a competitor.

Let us discuss handling characteristics through a corner. They can be neutral, oversteer or understeer. Circle track racers call oversteer “loose” and understeer “push”. It is easy to see how a rear engine car would oversteer because all of the weight of the engine is throwing the rear of the car outward causing toe rear tires to lose contact with he road surface and thus the rear of the car slides around. On slow corners this can be helpful because when done correctly it will position the car to exit the corner better. Oversteer can be induced by adding tire pressure to the rear tires.

Notice all of the car chase scenes in the movies and how the back of the car is sliding all over the place. It is simply done with added tire pressure. Over-inflation causes the tire to bow in the center causing little contact with the road. Practice slow corners with different rear tire pressures to feel the connection between air pressure and oversteer or the lack of it. Your ability to adjust your cars handling characteristics will greatly enhance your competitiveness on the racetrack.

Nikki Lauda, a formula one champion was outstanding at communicating to his mechanics what his car was doing. If you are planning to be a professional race driver, your ability to communicate with mechanics about the racecar can be a deciding factor if all other things being equal with competitive drivers.

Start the tire pressure testing at #30 on front and rear. Then, get familiar with that set up. Mark down in your logbook what your sensations were. Then change the rear tire pressure to #33, try that, and keep increasing it until you can feel the change.

Last of all, have someone set the rear tire pressure for you, then try to figure out what it is. Once you feel “dialed in” to oversteer and you feel the effect of the tire pressure, proceed to “dial” yourself into understeer. Begin by setting the rear tire pressure that does not induce oversteer, just a good “bite” of the rear tires. Mark the pressure number in your logbook. Front tires take a lot of punishment in corners because of the sidewall forces when the tire is turned and the car is heading straight.  The tire wants to fold over and high tire pressure straightens the sidewall of the tire.  These disruptive forces cause the front tires to lose the grip of the road.

Thus, they lose the ability to steer the car. All the while the rear tires have a good grip and are forcing the car in a forward motion. This is why stock cars drivers call understeer “pushing“. It is the rear of the car pushing the front of the car as if the front tires are on ice and the rear tires are not. All street cars are designed to “understeer” when driving over their limit. This is a safety feature designed into the suspension because reducing understeer is a simple matter of reducing speed to enable the front tires to get a “bite” again.

Oversteer on the other hand can become worse by reducing speed because you lose the centrifugal force effect of forward motion. Just picture a marble riding on the wall of a cylinder after being thrown into forward motion. As soon as the forward speed is reduced, the marble falls to the bottom of the cylinder. The feeling of oversteer and understeer have to be experienced to be understood like riding a bike for the first time. Practice raising and lowering the tire pressures; write your sensations in your logbook. After you are familiar with understeer and oversteer, adjust the tire pressure of the front and rear to as neutral of a handling character as possible. Then, record this tire pressure setting in your logbook.

Next, we will do adjustments of tire pressure from side to side and corner to corner because of weight transferring effects. It is easy to feel the effects of rear to front weight transfer when braking. Just take that scenario another step by turning the steering wheel. Here the outside front wheel has more weight on it because it is doing what it does not want to do through being forced to turn and the forward weight transfer of braking. At the same time the inside front wheel is lighter by this action.