Today’s cars, even passenger cars, are designed and tested with tools and concepts that weren’t available just two decades ago. But even with these advances, the design of an automotive chassis is fraught with compromise, as numerous design parameters, such as engine location, cabin space, safety and material considerations, and target costs, all play into what is needed. which will be the final design. Few automotive enthusiasts or laymen will bother to understand forces such as axial forces, shear forces, bending, torsion, angular deflection, and moments of inertia when shopping for a car. Engineers care about these things, but as we said, design compromises force many designs to compromise in favor of balancing a car’s characteristics toward a certain percentile of the population.
Car makers know that the job of a car’s chassis is to hold the vehicle’s components together while the car is in motion, all while being loaded by forces (such as vertical and lateral loads) transferred to it by the suspension, through through the wheels. With standard OEM components like tires, shocks, springs, bushings, and a stock drivetrain, any load transferred to the chassis can be handled by the original design. The problem arises when you add stickers and/or wider rims, stiffer springs and/or shocks, stiffer bushings, and more power. Then you get unwanted chassis flex that affects the way your car handles. A big no no then. And when you’re talking about a car that’s been on the road for more than a few years, you can add metal fatigue to the equation.
The best solution for a really stiff chassis would be a carbon fiber tub or a chassis that has been seam welded with a roll cage added. Very impractical for a street/strip car enthusiast who has to juggle a budget or just wants a good enough solution. Insert the chassis clamps. Veterans will immediately be intimately familiar with the simplest of these, the strut brace. This, even today, is one of the first add-ons you buy when you put a chassis clamp on your car. When cars were built with a separate ladder frame that the body attached to, there was also the subframe connector. Today, you have front and rear tie-rods, under-frame tie-rods, fender tie-rods, floor tie-rods, and rear suspension tie-rods to reinforce the rear-arm mounting points.
Obviously the effect of these clamps will be to stiffen the chassis to the point that adjusting the car’s handling will be a much more consistent affair. For those out on the track, these chassis clamps may not result in dramatic time improvements, but the improved confidence through better feel will improve consistency, which will affect the way the driver rides. This then indirectly can lead to better times. For less than new cars, these clamps will, as we’ve said, stiffen up the aging chassis to the point that the platform will be just as stiff, if not stiffer, than it was when it was new.
