Different tracks demand distinct car setups

Most NASCAR Nextel Cup teams have an entire fleet of race cars to compete on today's circuit. At a minimum, they will have two each for the various types of tracks -- Superspeedways, intermediate speedways, short tracks and road courses.

Some will break down their fleet even further and have specific cars for each particular track and race. The big multiteam operations are continually building new cars for testing, research and development or the replacement of existing cars either damaged or considered obsolete. They can easily have well more than 100 cars in various stages from construction to racing at any given time.

So where do all of the old race cars go? Some are sold to teams on other racing circuits such as ARCA. Some get handed down to developmental teams racing on the lower circuits. Some end up doing the circuit as show cars. And, some get "stripped and shipped" out as junk.

If a team hits on something that enhances a car's performance during testing then they may incorporate what they have found into their fleet or they might build completely new cars just to take advantage of whatever they have found. So why do they need so many cars just to compete in 30-plus races a year? Simply put, the competition demands it if they expect to have an opportunity to win.

The body configuration on a superspeedway car is totally different from that of a short track car, for example. Aerodynamics play an extremely important role on the superspeedway cars where they are not nearly as important on a short track car. (Pay close attention because there will be a test later.)

The experienced race fan can identify which type of car he or she is looking at simply by looking at the front end. If the nose has very few air intake openings, has a distorted look and practically sits on the ground then it is a superspeedway car because very little air flow is needed to cool the engine, and brakes and aerodynamics are at a premium.

However, if the front end sits more square and a little higher, has holes all over it to maximize air flow to the engine and brakes and does not have that slick, aerodynamic appearance then it is probably a short track car.

The intermediate track and road race cars fall somewhere in between the two extremes of superspeedway cars and short track cars. They will be more aerodynamic than a short track car and have more air openings than a superspeedway car.

The current race cars have to fit a specific set of templates to pass inspection but those templates are not attached or interconnected (like the COT templates are) so the teams can manipulate the templates to optimize the car's aerodynamics while staying within the boundaries dictated by NASCAR.

That is the primary reason that the noses of the current superspeedway cars look distorted like a guppy with a swollen jaw from a toothache or maybe how your wife looked last year at the carnival when she stood in front of that distorting mirror. Remember that one that made her look much fatter on one side than on the other? That was the same night you slept on the couch after that unfortunate comment while driving home from the carnival. Sure, now you remember. And all this time you thought your TV was distorting the picture when it is the front ends that are actually distorted to gain an aerodynamic advantage.

You could attempt to run the same car at all the different types of tracks but it is very doubtful that you would qualify for many of them simply because the geometry in the front end setups, steering ratios, drive train components and the body design, etc. (among other things) are vastly different. One simple difference, for example, is the size of the Goodyear tires vary based on the size and style of the track. You need a larger wheel well opening at Daytona than you do at Bristol because the Daytona tire has a taller side wall (slip angle) and therefore is taller overall.

While NASCAR has very strict rules and limitations on where pick-up points can be located, and what wheelbase lengths are permitted, etc. they do allow some leeway for the teams to build their cars in a manner that they believe is safer and more competitive. Basically, today's teams have so many different cars because they can.

If you cut the sponsorship money in half then they would probably get by with half as many race cars. But as long as one team can find the money and afford to build more and more cars, then the other teams have to chase the sponsor dollars that will allow them to stay competitive. As that old racing adage goes: "The square root of go is dough."

If you want to go fast then you have to spend the money to do it.

So what are the basic differences in the setups used for the various types of tracks?

First of all, tracks can generally be classified as "handling" tracks or "horsepower" tracks. That does not mean they are completely one or the other but that they tend toward being one or the other. A perfectly symmetrical track (all turns and straights are identical) will tend to be labeled a horsepower track because you can set the car up without having to make any concessions for any variances in the track.

However, a track that has variations in the size of the turns and/or their degrees of banking will tend to be labeled a handling track because you have to compromise your suspension setups to allow for those variations. There are no absolutes in racing but there are some predictable assumptions that can be made based on the laws of physics.

Let's start with some basic generalities for short tracks such as:

  • The shorter the track, the softer the spring rating you should try to run.

  • The more the corners are banked, the softer the spring rating you can run. (Bristol is an exception to this rule because of the higher speeds that are run there).

  • You would run more negative camber and positive caster in the right front and more positive camber and negative caster on the left front on a short track than you would on a bigger track.

  • You would definitely run positive Ackerman and bump steer.

  • You probably would run more rake and tilt depending upon the banking and tightness of the turns.

  • You might slant the rear end housing uphill (versus being square) just a bit to free the car up some to help it turn better in the corners.

  • Gearing would be critical in helping to accelerate and to help slow the car down to save on brakes.

  • You would make sure the pinion angle is slanted down slightly to help the car squat more positively and to get the rear tires to dig in more coming off the corners.

    We could give a laundry list of other things to do but basically you are setting up the car to go in a tight circle with repeated squats (gas) and dives (brakes).

    On a superspeedway your spring selection would be based on what setup you are trying to use. If, for example, you want the car to compress the springs and present a lower frontal area to the wind, then you would run softer springs. The aerodynamic downforce created at high speed would push down on the car and make it ride lower.

    On the bigger track you would run less negative camber in the right front and probably tend toward more neutral caster. Plus you would run less positive camber and neutral or a slightly negative caster on the left front because you are making a much wider arc in the turns and would therefore be creating less lateral load on the tire patch. Interpretation -- the front tires on a superspeedway car will be more upright than the front tires on a short track car. Your Ackerman and bump steer are not as critical on the supespeedway car and you would probably run less rake and tilt as you try to make the car more aerodynamically slick at the higher speeds.

    The driver may never lift off the throttle once he has achieved racing speed so dive and squat are not as important. However, high-speed wind buffeting a major factor, so you would try to make the car as stable as possible to improve the driver's comfort level and reduce the pucker factor.

    Again, there is a laundry list of other things to be done but you should be able to get an idea of the differences with the two setup concepts.

    Intermediate tracks fall somewhere in between the short track setup and the superspeedway setup. Cars that compete on tracks such as Darlington, Pocono and Dover, etc. will receive added setup considerations because of the idiosyncrasies of those tracks. Darlington, for example is shaped like an egg so each turn is different and must be accommodated in the setup calculations.
    Another example is that flatter ovals require different setups than banked ovals -- usually stiffer spring ratings and more caster and camber, etc. because the car wants to roll more on a flat turn.

    The short track setup and the superspeedway setup are designed to help the car to turn left. The chassis and the body are built with that concept in mind and the suspension setups are designed to complement that effort. But what if you also need to turn right as you do on a road course? The ballgame changes dramatically with a road course setup in the cars they will be running June 24 at Infineon Raceway.

    Road course setups are more sensitive to driver steering and braking input and must attempt to accommodate more variances in speed, braking and turning ratios, etc. than an oval track. The simple fact the driver will turn right automatically doubles the setup considerations. Then you have to evaluate if a track is evenly divided between left and right turns or has more left turns than right turns (or vice versa) to determine if you want a "square" set up where both sides are set up to mirror each other or have one that favors left turns more or right turns more.

    Road courses generally will have flatter turns so you will want to run a stiffer spring rating in the front and rear. Stiffer springs will also help the car to stand up more when making severe dives into corners in attempts to pass other competitors. You would also change your front end geometry to either be neutral on tracks with an even number of turns or lean the settings to favor either left or right turns -- whichever is more prevalent. You may even set the car up to be tolerable on 80 percent of the track but be superior in a good passing area and then do all of your passing in that zone.

    You would change the steering box ratio and set the rack to favor whichever turns are more prevalent. Did I lose you there?! Your passenger car has a steering system that will turn an equal amount to the right or to the left. Race cars, with rack and pinion steering and custom length control arms, etc., can be made to turn more to the right or more to the left depending upon what is desired.

    For example, short track cars will have more right hand turning capability than left hand turning capability because it takes very little steering input to get the car to turn left on a short track. But if the rear end breaks loose, it will take a lot more right hand turning ability to save it and get it back going straight again. It is an old dirt tracker's trick to offset the steering percentage to about 60 percent right and 40 percent left. On a road course you would calculate the degrees of the various turns and find the percentage of left or right turning capability you would want factored into the rack setting when you set up the front end of the car.

    A road course requires an engine and gearing that would provide a wider torque range because of the variances in the size and length of the turns and straights. Brakes take a beating on road courses so you want to get as much air flow to them as possible to keep them cool and reliable.

    And, don't forget that road course cars go in the opposite direction from oval track cars. NASCAR oval races go counter-clockwise where road course races go clockwise. That causes a whole different set of problems for the setup experts.

    Now you are an informed race fan and can identify the different types of cars from their front end configurations, right? I told you there would be a test, now see how much you've learned and tell what type of course each pictured car is set up for in the above photos.

    The answers are: A. Intermediate (Texas Motor Speedway); B. Superspeedway (Daytona International Speedway); C. Road course (Watkins Glen International); and D. Short track (Martinsville Speedway).

    Bill Borden is a former championship winning crew chief who operated David Pearson's Racing School for many years.