Longacre Racing Products just introduced what could be one of the most innovative advancements for scaling your car-its new Side Sliders. When you jack up your race car to put it on scales, the front wheels camber in toward the center of the car, as you let it down onto the scales the wheels (and scales) must be able to freely move sideways to prevent any binding of the chassis. If the wheels and scales can't move sideways the chassis will go into a slight bind and it will not settle out completely. Cambered wheels and a chassis in bind will have an adverse effect on the weight readings and thus the accuracy of your setup.
Up until now the solution has been the use of roll-off leveling fixtures that allow the car to roll back slightly, then forward, thus relieving this bind. For the most part these systems work well, however you must perform the back and forth roll several times to eliminate as much bind as possible.
The "slip plate" is a system featuring two metal plates with a low friction surface such as Teflon-coated plastic in between. While these units work reasonably well, they are low-friction, not friction-free, and there will likely still be a small amount of resistance and some residual bind in the chassis.
Enter Longacre's Side Sliders which have completely eliminated that friction through an innovative design, the inspiration for which came from a bit of past history. Racers have been using scales of one sort or another for a long time. But before electronic digital scale systems came along teams used mechanical grain scales. While crude by today's standards, grain scales had one big advantage. They had rollers on the bottom that allowed the platform to move sideways, relieving any camber bind.
Longacre's engineers brought this concept into a 21st century design that features a series of rollers held together with metal retainers. The scale pad sits on top of the rollers, allowing it to move sideways virtually friction free. As the car is lowered onto the scale pads the wheel and pad move sideways to the natural unbound position. Since the left front is the wheel that usually has the most camber gain, only one Side Slider is needed to relieve the bind on both sides. Spacers of equal thickness are included for the other 3 corners to maintain a level setup.
Getting the car on the scales bind free is not the only benefit. If you push down on the car to move the suspension you can see the scale pad on the Side Sliders moving sideways slightly, relieving any bind. Without Side Sliders the suspension would not move completely freely and any adjustments you make might not show up in the wheel weights exactly as you intended.
Get the most out of your scale's system by making them truly bind-free. These Side Sliders will work on any scale pads with very smooth or machined bottoms and a smooth floor. Could be the oldtimers that swore by grain scales knew something after all.