Chassis Adjustments - Don't Forget!

One of the most enjoyable challenges in stock car racing is finding that perfect setup package that makes the race car feel like you've got Velcro tires and you're racing on a felt track. Like any pitcher throwing a perfect game, or a golfer hitting a hole in one, nailing that absolutely perfect setup is an all-too-rare occurrence and should be enjoyed whenever possible.

Modern race cars, even Street Stocks and Legends Cars, allow many tuning options. But that can sometimes be a double-edged sword. With so many options available, it can be easy to confuse exactly what does what, or even overlook a tuning change that can take your race car's handling from good to great. Most of us find those chassis adjustments that work well and go to them more often then the rest. That's OK, and even the Cup crew chiefs do it. But what you shouldn't do is completely ignore other tuning options available to you. It's like throwing away half the wrenches in your toolbox.

Stock Car Racing asked several chassis builders what adjustments they most often have to remind their customers to check. And then we asked crew chiefs and racers the same question. Their responses run the gamut, so we're presenting what we feel are the most helpful tips.

Chassis builder Gene Leicht of Leicht Race Cars says he often has to remind his customers to check the sway bar in the front of the car. Most racers won't forget that they have a sway bar in the car, but since it's usually contained within a tube on a handbuilt chassis, it's easy to forget the size of the bar in there.

If you can't see the sway bar size right away, it's always helpful to take a moment to double-check what size is in the car. It's possible that a random bar was put in during the setup process for the purpose of scaling the car.

This is not necessarily a chassis adjustment as much as it is a reminder to check for damage when your race car mysteriously loses its handle. Chas Howe of Howe Racing Enterprises gets calls from customers complaining about a chassis that will not respond to adjustments. He says his usual test is to ask them to change the rear stagger in both directions (right rear larger diameter and right rear smaller diameter). If the race car's handling does not change significantly, then he says the culprit is almost always a bent rearend tube.

Whenever the rear wheels make contact with another object, either the wall or the wheels of another race car, there is the potential to bend an axle tube on the rearend housing. This can often be difficult to detect without completely restringing the car, including squaring the rearend. A bent axle tube throws off the rear-wheel geometry and changes such as stagger or putting a little angle into the rearend won't have much effect on the car. The good news is Howe says that often only the axle tube will be bent while the rearend bell will still be good, so the rearend can be repaired instead of junked.

Instead of pointing to specific chassis adjustments, race car builder Charlie Barham of FNO Race Cars points out that you often must define where on the track the race car needs help first. This is because different components will have greater influence on how the tires maintain traction, depending on what the driver is doing. For example, on turn entry, the brakes are the predominant force in play. On turn exit, brakes are obviously no longer an issue, but the throttle, specifically how power is put to the ground, is the main factor affecting the car.

To take it a step further, if the handling problem occurs on turn entry, you should concentrate on the front suspension because the car is decelerating and the weight transfer is over the front wheels. Monkeying around with the rear in an attempt to fix a handling problem on turn entry will not have as much of an effect because the rear wheels are only lightly loaded.

On the other hand, the driver is applying progressively more throttle during turn exit so that the weight transfer is over the rear wheels. Now you should turn your attention to what's going on in the back half of the car. This can help you separate the many available chassis adjustments into areas where they will be most helpful. Make front spring changes to dial-in the car from turn entry to the center of the turn. Save rear spring changes for perfecting the car from the center off. A track bar change, for example, should come to mind as a priority if your car isn't handling well when accelerating out of a turn.