Track Testing - How To Go Testing

Track testing provides an opportunity to dial in the car to a particular track for speed and consistency. Most events don't offer enough time for adequate evaluation of our chosen setups, so we need to take advantage of every chance we get to go testing.

I recently tested at several racetracks with an ASA Late Model Series South race team and recalled some of my previous experience over the years. What I learned was that the basics don't change, even with some of the new and innovative setups we now see. Suspension binding and broken shocks still throw off test results.

There is a specific order we must follow during testing to get the most out of the experience. Let's look at how we might organize and run a typical test session and discuss methods and procedures we can use for a more productive session. The process is mostly the same for dirt and asphalt, with some minor differences.

All testing and practice involves trying different combinations of setup and chassis geometry that might make the car faster. As we have stated before, we are searching for an unknown by making intelligent choices in reasonable directions. What we don't want to do is start out with a car we don't know very well and throw springs and other parts at it while hoping for a miracle. The top race car consultants would never work with a car that didn't have critical information readily available.

The overall goal of testing is to find a setup combination that is initially fast and remains fast for a long time. It should be good on the tires, comfortable for the driver, and should enable the driver to outrun the competition from start to finish.

On asphalt, the final setup is probably the one we will qualify and race with, given small changes between the two. For dirt, the changes required for each segment might be much different. That does not mean we cannot test on a track that is consistent.

Dirt testing involves trying various settings and bolt-on parts to find what makes the car do what we need it to do. Getting the car to turn better will help us throughout an event, and finding methods of adding forward bite can help us get off the corners better for the dry and slick conditions.

A primary goal might be to learn the process of making changes to meet track conditions. There is an order and logic to adapting to changing track surface grip levels. Becoming comfortable with making those changes can be a huge performance gain.

It is most important to be familiar with the car prior to going to the racetrack for practice or testing. This means that the front and rear geometry have already been evaluated, the car is aligned, and a dynamic analysis of the spring combinations has been accomplished to balance the two suspension systems. Also, the shocks have been dyno'd and tested, the springs have been rated, the steering system has been checked for Ackermann, the car has been weighed, and the motor has been prepped.

The type of racetrack should be taken into consideration if this is the first time the team has been there. If it has a different banking angle from what the team is used to, a different moment center design might be in order. High-banked tracks have little need for traction-enhancing technology, so rear steer characteristics and ride height must be planned if excess chassis travel is an issue. If the track is flatter, methods of creating bite off the corners should be included in the planning.

If the team is unaccustomed to the length of the track, a rear gear in an acceptable range should be calculated or someone on a team that has run on the track should be asked about gear ratio. If testing is taking place on dirt, the correct tires are needed for the anticipated conditions.

In the days before we leave the shop, we must prepare a plan of attack that defines the changes we will make and the areas in which they are made. This plan may be written on paper or mentally noted. It should be discussed with the entire crew so they can have input into the process and know the direction the test will go in order to be prepared in their particular areas of expertise.

Having a prepared plan is very important for getting good results. As the test proceeds, the result of each change (both positive and negative) should be noted. We probably learn more from the negative results than from the ones in which gains are made. That is because we more readily remember losses in lap times and how to avoid the things that the car does not like.

If different combinations of spring rates are to be used, we need to weigh the car with each combination of springs and note the position of the spring adjusters, which may be the coilover rings on the shocks or the jack screws used in the big spring cars. Doing this allows us to quickly make spring changes at the track and ensure that the weight distribution has not changed.

If we intend to compare different layouts of shocks when making individual corner changes, we need to mark the shocks according to where they will be placed on the car and give them set numbers. The tire sets must be marked as well so that we do not mix tires among sets. Using a tire of a different age (meaning date or laps used) from the other three can throw o the setup quite a bit. Many tests have been upset by the use of an odd tire.

Once we have arrived at the track and unloaded the car, we need to establish a pitting position for the car that is relatively level. We should have easy access to the tool cart, the trailer, and other track facilities that may be needed. The spots around the tires are marked with duct tape in order to park the car in the same position after each run.

Many teams weigh the car in that location and note the relative weight distribution if the scales cannot be leveled. The weights read will almost always vary from the shop numbers due to the scales being out of level.

It is best to level the scales and weigh the car before testing. Then, after all the testing is done, the car is reweighed to see how the weight distribution might have changed from the various adjustments.