The following is the final examination for a graduate level engineering course I taught on the dynamics of race cars. Thought you might enjoy the challenge.

__ Reference to an "oval track" car is reference to a race car which competes on a closed course and encounters only left hand turns. On such cars, it is assumed (unless otherwise stated) that there is a "beam" axle suspension at the rear (located by trailing links and a Panhard rod) and independent suspension at the front. Also, it is assumed that the chassis reaction points, for the four coil suspension springs, are vertically adjustable by jackscrews, as is the chassis mounting point for the Panhard rod.

Unless stated otherwise, the car is assumed to be rear wheel drive.

You are expected to discuss the effects any proposed change might have on other parameters. If you anticipate that a proposed change must be followed by actions to return other parameters to their original values, you must so state and describe such actions.

Reasonable sanctioning body rules must be assumed. For instance, 60% leftward weight bias, for an oval track car, would be reasonable; 90% would not. No sanctioning bodies presently allow auxiliary devices to create a low pressure region beneath the car, so you need not mention something like this as a solution. __

1> How are the cornering characteristics affected:

  a> as the brakes are applied, while entering the turn, and

  b> as engine torque is applied, while leaving the turn?

2> The driver of an oval track car reported that the car was fine on turn entry, but was loose on exit. After the right front tire was replaced with one of larger circumference, the driver reported that the car was fine throughout the turn. Explain.

3> Using only jackscrews and tire stagger (and, of course, those tools and measurement devices common to a race shop), correct the following problems for an oval track car:

  a> Loose at turn entry, tight at turn exit

  b> Loose at exit

  c> Loose at entry

  d> Tight throughout turn

4> Discuss the reasons for the long wheelbase common to those dragsters that exceed 300 miles per hour in the quarter mile.

5> Discuss the effects of a locked rear end (no differential action) on constant speed cornering behavior

  a> at low lateral accelerations, and

  b> at maximum lateral acceleration (breakaway).

6> Discuss the effects of rear stagger on an oval track car, in conjunction with a locked rear end:

  a> at turn entry, and

  b> at turn exit.

7> Repeat the previous question, but with an open differential.

8> Discuss the use of front stagger on an oval track car.

9> The polar inertia of an engine is reduced by 90 pounds mass inch squared. The car has a 2.6 first gear, a 3.76 axle ratio, and tires that turn 750 revolutions per mile. What is the reduction in equivalent mass in first gear?

10> Discuss the effect of brake bias adjustments on turn entry cornering behavior, including consideration of adjustment limitations.

11> Rear tire air pressure, instead of stagger, is often considered an adjustable parameter for the control of cornering performance. If a spool is used, how would an air pressure adjustment be different, in effect, from a stagger adjustment.

Bill Shope