Proper chassis setup is critical to performing successfully on the track and finding your way into victory lane. In order to get a perfectly set up race car, you’ll need a couple of simple but very useful tools. A routine procedure is the primary tool that any good race team needs, yet it costs absolutely nothing. Without a good procedure for scaling however, chassis set up is almost impossible. The second tool is a good set of electronic scales. No matter how good your pre-race procedures are, without the right tools the job cannot be accomplished.
Proform Parts offers a very good set of car scales for budget or traveling series racers that need a set to take on the road. With a price that will fit in any racer’s budget, no matter how tight, this economy scale set is more than worth the expense.
Proform Part’s electronic scales (Part #67650) have a 1,250 pound capacity per scale pad, and will accommodate up to a 5,000 pound car. This scale kit helps you get your chassis ready for the track by providing individual wheel weights, total vehicle weight and percentage weight.
Features of the Proform Parts’ Electronic scale kit:
- Four electronic weighing pads with central display unit.
- Each weighing pad has a capacity of up to 1250 pounds (567 kg).
- Display unit operates with four AA batteries.
- Display indicates percentage load of each wheel to the total.
- Display shows loading in pounds (or kg.) of each wheel to the total by pressing “kg/lb”.
- Display has an interactive center of gravity in graphical form.
- Display shows total vehicle weight.
- All information displayed on one LCD screen.
- Low battery indication.
- Display unit with connecting cords housed in a single box.
About the Proform Part’s Electronic Scale Kit
The scale kit’s black powder-coated aluminum weighing pads are a compact 14 1/2” wide X 9 1/2” long pad that is only 2 1/2” high. These pads are conveniently sized to easily position under the tire’s centerline for accuracy, which is advertised as accurate to 1/10th of 1%.
We tried Proform Parts scale kit out with our chassis set up procedures for a full race season to evaluate the performance and dependability of these economy scales. After a season’s use we can honestly say that the scales performed exactly as advertised from opening day till the last race of the year.
We found the accuracy of the scales to be very dependable and the size of the scale kit to be compact enough to store in the race hauler and cary to the track routinely. It would be difficult to beat this scale kit’s value-to-price ratio. We found that using the procedure below was effective for setting up the chassis on our project cars:
1. Get the car race ready. Top off the fluids and have the fuel level set where you expect to have it near the end of the race. Tire stagger, tire pressures and ride heights need to be set at their race-ready state. It is critical that the car be ‘race ready’, including weight in the driver’s seat that is equal to the weight of the driver.
2. Make sure the rear end is square to the chassis. Do an initial caster, camber and toe setup. Set the bump steer, and ensure that any parts that are off the car are replaced, like the battery, before the car is scaled.
3. Find a level area to weigh the car. Take the time to ensure that the surface is flat by using a string and level. It’s best if you use the same spot every time you scale the car. Marking the wheel position on the floor (LF, RF, LR, RR) will speed up the process and accuracy for any future scaling process. If the scales need to be shimmed for low spots on the floor, using 12” X 12” linoleum squares as shims work well. Make sure to mark the shims with wheel location as well.
4. Set the weight pads next to the wheels making sure that the tire does not touch the weight pad. Connect up the electrical cords to the proper weight pads and zero the scales by turning the unit on and pressing ‘TARE’. Ensure that the scales are reading pounds and not kilograms.
5. Lift the car and place the center of the weight pad under the centerline of the wheel.
6. Slowly lower the car onto the weight pads until all the weight of the vehicle is on the pads.
7. Disconnect the shock absorbers to be sure that they do not hold the chassis off the springs. We also like to disconnect the sway bar linkage to ensure that there is no preload on the chassis.
8. Bounce each corner of the car up and down to settle the suspension.
9. Set the ride height at each corner.
10. Scale the car and adjust the weight accordingly.
11. Set cross weight.
12. Reset caster then camber.
13. Set bump steer.
14. Set toe out.
15. Double check weight distribution. Remember that everything on the race car is related so it is almost impossible to make one chassis change without affecting something else. Make an adjustment, then double check the weight distribution for all parameters again.
16. When weights are adjusted to the target goals, raise the car and remove the scale pads. Don’t forget to keep good records on what adjustments you made and what the final results were. Keep good track records so you know what adjustments worked and which ones didn’t.
Getting Great Results
The biggest factor in scaling your race car is repeating the procedure as closely as possible every time. Consistency will allow you to make the most of your scales and chassis set up. Settling the car on the pads the same way each time, consistently following the same procedure with each adjustment, and routinely changing the batteries in your electronic scales are critical in getting the best results. As with any good tool, Proform’s electronic scales are only as good as the technician performing the work.
10 Keys to properly scaling your race car.
- Find a level surface. Use linoleum 12”X12” squares as shims if needed.
- Zero out your scales.
- Make sure the car’s fluids are the same each time. Fuel, oil, etc.
- Check for suspension binding
- Make sure the tire pressures are the same each time you scale the car.
- Position the scales under the center of each tire.
- Disconnect the shock absorbers to be sure that they do not hold the chassis off the springs.
- Bounce the car to settle the suspension. Start in one corner and move clockwise around the vehicle. Start in the same corner each time you settle the suspension.
- Write down the weights every time you make an adjustment.
- Periodically check the tire pressures when scaling.