At a recent test session at...
At a recent test session at Concord Motorsports Park we were able to apply some of what we preach. Track testing is how we get better. A plan is developed and data is collected accurately in order for the team to properly analyze what went on and what changes made the most impact, both positive and negative. That is how we learn.
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.
We recently tested at Concord Motorsports Park with our USARacing project car that John Gibson will drive. What we learned was that the basics don't change even with some of the new and innovative setups we now see in this, and other, series. Suspension alignment problems and unbalanced setups will still throw off your test results.
Testing is a process that should follow a specific order 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 that you can use for a more productive session. The process is mostly the same for dirt or asphalt with small differences.
All testing and practice involves choosing a setup and chassis geometry that might make the car faster. 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 so on, at it hoping for a miracle. The top race car consultants would never work with a car that they don't know critical information about.
Goals
The overall goal of testing is to find a setup combination that will be both initially fast and also stay fast for a long time. It should be good on the tires, comfortable for the driver, and outrun the competition all the way to the last lap.
On asphalt, the setup we end up with is probably the one we'll qualify and race with given small changes between the two. For dirt, the changes required for each segment might be much different. That doesn't mean we can't 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. If we can get the car to turn better, that will help us all throughout an event. If we find methods of adding forward bite, then we can get off the corners better for the dry and slick conditions.
Before our test, we had the...
Before our test, we had the team from RaceWorks install PI data acquisition components so we could monitor all of the vital functions on the car for later evaluation. We had shock travel sensors, load sensors, g-force in X-Y-Z axes, as well as steering montoring. This data would later provide us with the needed information we could use to run the seven-post rig to refine our choices.
A primary goal might be to just learn the process of making changes to meet the track conditions. There's an order and logic to adapting to changing track surface grip levels. Becoming comfortable with making those changes can be a huge performance gain.
Pre-testing Preparation/Planning
It's most important to know your car before you go to the racetrack for practice or testing. This means that you would have already evaluated the front and rear geometry, aligned the car, and done a dynamic analysis of the spring combinations to balance the two suspension systems. We should have tested and dyno'd the shocks, rated the springs, checked the steering system for Ackermann, weighed the car, and prepped the motor.
Take into consideration the type of racetrack if you haven't been there before. If it has a different banking angle than you're used to, a different moment center design might be in order. High-banked tracks have little need for traction-enhancing technology, so plan out your rear steer characteristics and ride height if excess chassis travel is an issue. If the track is flatter, include methods of creating bite off the corners into your planning.
If the length of the test track is different than you're used to, calculate a rear gear that would be in an acceptable range or contact a team that has run the track and ask it about gear ratio. If you're testing on dirt, pick the correct tires for the anticipated conditions.