Stock Car Practice Sessions - Track Testing Tips

Having a prepared plan is very important for getting good results. As the test proceeds, each change can be noted as to the results, both positive and negative. We probably learn more from the negative results than from the ones through which gains are made. We can more easily remember losses in lap times and how to avoid things that the car doesn't like.

If different spring combinations are to be used, weigh the car with each combination of springs and note the position of the spring adjusters, either coilover rings on the shocks or the jack screws used in the big spring cars. That way, spring changes at the track can be made quickly. Be sure the weight distribution has not changed.

Mark the shocks as to the corner of the car where they will be used, as well as to their set numbers, if comparing different layouts of shocks when making individual corner changes. The tire sets must be marked, as well, so that tires are not mixed among sets. Using a tire of an age different from that of the other three (meaning date or laps used) can throw off the setup.

Be sure to stock up on drinks and food for the test session. Tests are usually not stopped for lunch, so most crewmembers sneak in a snack when they are not needed for the moment.

Once you've arrived at the track and unloaded the car, establish a pitting position that is relatively level. There should be easy access to the tool cart as well as the trailer and other track facilities that may be needed. Mark the spots around the tires with duct tape so that you can park the car in the same position after each run.

Many teams will weigh the car in that location and note the relative crossweight. It will almost always vary from the shop number, due to the scales being out of level, compared to the location of the shop scales. Level your scales and weigh the car before on-track testing. After all of the testing is done at the end of the day, re-weigh the car to see how the weight distribution might have changed from the various adjustments.

An additional check procedure for use in maintaining proper ride height, after spring or camber changes, is to measure from the bottom of the rim to the highest edge of the fenderwell or to a mark on a piece of tape on the fenderwell. As we make changes that could affect the ride height, we can easily adjust the spring heights so that the original ride heights can be preserved.

Before the car leaves the pits, check air pressure, lug nut tightness, fluid levels, and all bolts and nuts. Hood pins must be secured, the window net must be up and secure, and all spotters should be in position.

When practicing among other cars, use a spotter for the driver to safely enter and exit the racing groove. Running a test session with other teams is beneficial because lap times under similar track conditions can be compared to others.

A bonus of practicing in groups is the availability of odd springs or other parts that can be borrowed from the other teams. You should always be willing to return the favor if another team needs a part. Keep a notebook handy to record parts borrowed or lent. It is easy to forget in the heat of the moment.

There are two components to speed-the motor/drivetrain combination that gets us down the straightaways, and the chassis setup combination that gets us through the turns. Because work on these elements is done separately, they must be measured separately.

A car can be the fastest in the turns and be off down the straights for a number of reasons. If lap times include turn segment times, those times can be compared with the competition. Turn segment times tell everything about chassis setup experimentation. Turn segment times, in addition to total lap times, should always be recorded. Compare total times and segment times to other fast cars.