When It's Time To Fine Tune A Racecar, Our Alphabet Soup Of Ideas Can Help Put You In Victory Lane
Here is the elaborate Cup way of setting up a racecar. This is nice, but the average racer can accomplish the same thing with a string and a couple of jackstands. Kevin Thorne
The debate will always be present: Other than the driver, which is more important to the success of a team, the chassis or the engine?
Engine builders will tell you that a great motor will make up for an inferior chassis setup. Chassis manufacturers will tell you that a perfect chassis setup will more than make up for an engine with less power.
The debate can't be proven either way. A great engine needs a decent chassis; a great chassis needs a decent engine.
But the fact is, to have a greater chance to be up front every week, you need to have a good grasp on your chassis and the setup you are putting underneath it. There are so many variables that affect your chassis, that it will take some time and effort to make sure everything is perfect. So without further ado, here is a list of chassis tips from A to Z.
Always remember to check your ride heights.Each chassis has a certain ride height for each corner of the car when it's manufactured. You need to find out what these heights are, so that before you weigh the car you can set the ride heights and put the car on the scales to determine the percentages. More than likely, your crossweight is going to be off from where you want it to be, so work with your weight jacks to keep your ride heights while setting the crossweight.
Bumpsteer your car!If you have weighed the chassis and the toe is set, which is to make sure the front two wheels are tracking as straight as possible, remember that as your front suspension travels it will actually make you lose camber on both front tires, which in turn will affect your toe. The trick is to use a bumpsteer gauge and find out how much your car is "bumping out," which means as your car travels it is actually being towed out at full travel. By using a bumpsteer gauge you can limit it to a minimum and keep your front wheels almost perfect as the car travels.
Is it the engine, driver or chassis that vaults a team to success? You can argue for any one of them, but one thing is for sure, each one has to be examined closely to have a legitimate shot at winning the race. Your chassis might be the most particular out of the three because there is so much that goes into preparing a chassis for competition. Kevin Thorne
Crossweight is vitally important.I wish that there was a magic number for the percentage of cross you need to run. But there are just too many factors that go into determining the right amount of crossweight. First, let's understand what crossweight is: the amount of weight that is on your right-front tire and your left-rear tire compared to the amount of weight on the other two tires. So if you have 52 percent cross, you have 52 percent of your weight on those two tires. Most of the time, more cross results in having a car with a push in it. However, this isn't always true. When I raced Karts on dirt, we would wait for the track to develop a lot of bite, or grip, then we would put cross at 70 to 73 percent and the Kart would be extremely fast. The best thing to do is keep talking with your chassis manufacturer and find out where the rest of his buyers are running their cross.
Decide before leaving the shop a list of possible chassis changes to make at the track.Having a game plan before you leave your shop is always a great idea. After the car is ready to go to the track, take out a notebook and make a list of changes you would like to do given a particular situation. For dirt competition, for instance, let's say the track is notorious for drying out and building a lot of rubber. If you stick with the same chassis setup all day, you are more than likely going to find your car going through some extreme handling changes. It might start out loose, but as the track gets some bite in it, the car starts to stick a little too well. By listing the changes you would like to try, you will be better prepared when that situation arises. On dirt it becomes extremely important to stay on top of the track and make changes to your chassis setup to keep grip in the tires.
Extra weight is always a bad thing.If your weight rule is 3,000 pounds, you should not be running 3,050 pounds. You need to do everything you can to lose the weight that is pushing it over the weight rule. I run our car only 8 to 10 pounds heavy to make sure I can make it through post-race tech. Many divisions will allow you to refuel the car after the race to make weight.