A race car needs a certain...
A race car needs a certain crossweight percent based on that car's front-to-rear percent. The more rear percent, the more cross is wanted. We do not use crossweight percentage changes to alter the handling of the car. We should match the crossweight amount to the car and then adjust the setup to find the best dynamic and handling balance.
Because there is only X amount of load available, increases in that diagonal mean a tighter car. This only happens when we accelerate and the loads shift front to rear, so we tighten the car off while not affecting the mid-turn handling.
Rear spring split can also increase the crossweight percentage. This method is very "old school," but very effective. In days past, racers used to run a softer RR spring rate over the LR spring rate so that when accelerating, the LR and RF diagonal gained load and the crossweight percent increased.
Today on the same flat tracks we are talking about helping with bite off the corners, if we ran softer RR spring rates with a setup that was balanced for mid-turn dynamics and handling, we may well outrun those BBSS setups that currently use the stiffer RR spring rate.
There are many devices you...
There are many devices you can use with the rear suspension such as this double unit from Coleman Racing. The upper link controls acceleration and the lower link controls deceleration and the return of the upper link when you lift the throttle.
The only way the BBSS setups work on the flat tracks is to load up the RR corner with an unbalanced loading at mid-turn so that the RR tire drives the car off the corner. But after 20 or so laps, it is worked so hard that it gives up. The softer RR spring layout would keep biting and beat the BBSS setup in the long run.
Throttle control will allow the rear tires to maintain their grip on the track surface and help to provide better acceleration. Once we lose grip in the rear, we must back off the throttle until we regain grip before we can continue to accelerate. By exercising throttle control, we may feel like we are giving up performance, but in reality, we are providing the most acceleration possible.
Throttle control is defined as the modulation of the gas pedal through a range of motion, never moving quickly from one position to another, in order to keep the tires in contact with the track surface. The rate of change in throttle position must be altered depending on your position on the track and through the corner, so the driver must develop an educated foot.
Many drivers report that they never got past half throttle over the course of an entire race they won. This means that they were working from off throttle to half and many points in between. It is the developing of efficient throttle modulation that is one of the most effective tools you can use to promote bite off the corners.
The rubber biscuit has been...
The rubber biscuit has been around for some 10 years now and has shown to be of use if the pre-load is set fairly high. If not, the 1/4-inch plus of movement is way too much rear steer. This apparatus can be used on the right side of dirt cars with the spear rod attaches to develop rear steer that will straighten the rear end more toward square on acceleration off the corners. Dirt cars usually utilize rear steer to the right for entry and mid-turn efficiency, but need a more straight ahead position for the rear end when coming off the corners.
The above suggestions may at first seem like a bit few compared to all of what we know about chassis setup, but remember that we have supposedly already solved the critical issues facing our race car. We have aligned it, checked the moment center design, checked for binding in the suspension, rebuilt the shocks, and done all of the other maintenance things we know we should.
The last thing to do is run the car. Teams that are conscious of the effects of all of the various changes and know basically how much affect each change has on the handling of the car will go through the process fairly quickly. Three or four times out with 10-lap runs or less will be all they need to get to the sweet spot. If you're just learning these things, take good notes and concentrate on what is happening. Ask lots of questions of your driver so you can know exactly what the changes do and how much. And when you do get the car all dialed in, be sure to maintain that good setup
You Might Have A Handling Problem If...
• If you race on asphalt and you ever have to turn the steering wheel to the right, you might have a handling problem.
• If you race on dirt and you have to turn the steering wheel way to the left, you might have a handling problem.
• If you see excessive heat or wear on one tire versus the other tires, you might have a handling problem.
• If you are more than a half second slower than the fastest car on the track, you might...
• If your car starts out the race fast and then trails off, you might...
• If you get lapped in a 50-lap race, you might...
• If your driver is worn out and sweating profusely at the end of the race, you might...
• If your spotter is continually saying, "inside, inside..." and you keep getting passed, you might...
• If you have to wait longer than your competition to get back into the throttle, you might...
• If you bought that $25,000 cheater crate motor, run illegal fuel, soaked your tires, and installed traction control, and are still getting beat, yes my friend, you might just have a handling problem.