Next, you need to determine exactly what you are trying to accomplish. For example, you may be trying to test some new components to see how they make your car react. In this instance, you aren't as concerned with determining the absolutely best setup as you are with gathering information that can be used later. You may be testing a new brand of shocks and need to learn how different settings affect the handling. And then how do the different shock settings react to different spring packages? This type of test is more about gathering information that should help you make adjustments on the fly during your next race.

The other type of test is all about determining the best setup package for a given track (and hopefully, under the same conditions you will be racing under). Work as if you are actually racing and try to find that right combination that will produce the fastest lap times while also keeping the car comfortable enough to drive that you-or your driver-can successfully negotiate traffic and pass when necessary.

At the Track
Remember, the entire purpose of going to test is to gather all the information you can. You won't learn nearly as much during the time spent wrenching on the car, so try to minimize that as much as possible. Sibley says you can make your test run much more efficiently if you prepare your packages ahead of time, including scaling the car. If you know what shock and spring setups you will be running, go ahead and set them up at the shop beforehand. Also, for example, if you plan to try a softer left rear spring, go ahead and install that spring on the car and measure how many rounds you will have to put back into the rear to get the ride height back to where it was before. Now when someone installs that shock and spring package, your crew can just count the rounds on the jack bolts and know everything is right.

And then there will be times during a test that you may want to make a chassis adjustment you hadn't originally planned on. Now you will likely need to recheck frame heights to make sure you aren't getting off track on your overall setup. An easy way to do that is to put a piece of tape on all four fenders and, while you are still at the shop on a level surface, mark a line on the tape at a consistent height on all four corners. Next, find the most level spot you can at the racetrack and use that as your pit area. Measure those four marks again and log the heights. The height may change versus what you measured at the shop if you aren't on level ground, but now you know your frame heights and can tell if they change. Now every time you make a change to the chassis you can easily refer back to those points to see if the frame heights have moved.

Whether you are simulating long green flag runs or shorter sprints, there are some things you or your crew should check every time the car comes in. This includes tire pressures, recording how much the pressure has changed since the car left the pits, and shock travels. You have to be careful with shock travels, however, if you are using rubber grommets on the shock shafts. That will only tell you max shock travel, which can sometimes be thrown off if you hit a bump or a hole in the track. A hard transition from the track to pit road can also max out your shock travel. Still, travel indicators are a good way to see if any change you made to the chassis is affecting shock travel.

Another often overlooked area is communication between the driver and crew. If you have a long working relationship with your driver or crew chief, you have probably already worked through this, but for new drivers or crew chiefs it is important to talk beforehand about exactly what you mean when you describe something about how the car is handling. On the surface this may not seem like a big deal as long as you both speak English (or at least the same language). But we're talking about degrees of difference here. Most racers and crew chiefs settle on a scale to describe just how loose or tight the race car may be. Sibley says whether you use a scale that's 1-10, A-Z, or whatever; you need to make sure you mean the same thing when the driver says the car is a "seven loose." Otherwise the crew chief may over- or under-compensate on his chassis changes and it will take longer than necessary to dial in the chassis.