In building the Banks Sidewinder D-Max Type-R endurance road racer, Banks' crew could have simply duplicated the front suspension of a NASCAR Craftsman Truck Series chassis. But then, they would have been locked in to a design that wasn't optimal for the anticipated road courses or the tires that would be run. Proper suspension design for any racecar (or truck) begins with the performance characteristics of the tires that will be used. The Banks Sidewinder D-Max Type-R will use Goodyear Eagle 25.5x12.0-17 racing tires on the front. Suspension design was based on data provided by Goodyear, along with anticipated tire loads determined by vehicle weight and racetrack configurations.

One of Banks' drivers, Don Alexander, in conjunction with Sheldon Tackett, an experienced chassis designer and builder, designed the suspension with the aid of computer software programs to model suspension geometry that would be ideally suited to the D-Max Type-R. Both front and rear suspensions were designed at the same time to achieve total vehicle performance goals. Such programs specify suspension attachment and pivot points. However, utilizing the suggested locations is not always feasible due to clearance problems or interference with other components such as the engine or frame rails. Alexander and the Banks crew evaluated nearly a dozen designs before a workable setup was selected. Once a suspension design was deemed workable, construction of the chassis engine/front suspension section was completed. This included engine mounts, suspension mounts, front crossmember, and steering attachment brackets. Then, the actual suspension A-arms and front spindles were fabricated and the necessary mono-ball joints, spherical rod ends, and mounting eccentrics were added. With the suspension pieces and Woodward Type-H steering rack-and-pinion bolted in place, suspension and steering movement was plotted to ensure that it matched the design specifications, with minimal changes during bump and rebound travel. Adjustment is built into the suspension design for track tuning and ride height. Vertical movement is controlled by Koni 2812 Mark II series double-adjustable coilover shock absorbers with Eibach Springs.

Dave Royce at Eibach worked with the Banks Race Shop crew to help to determine spring rates for the front and rear Koni shocks. Front springs are 500# main spring (7”-long, 2-1/4” i.d.) while rear springs are 600# main spring (8”-long, 2-1/4” i.d.). Helper springs are also used to keep the spring from coming loose when suspension is in full droop. These first Eibach springs are only the starting point - many more additional sets of springs will be tested and evaluated once initial road/track testing has begun. The goal is to have several different spring combinations available for different tracks and varying conditions. Additional fine-tuning will also be done with spring and shock absorber adjustment, in addition to varying front tire pressure. A Speedway Engineering tubular front sway bar controls front-end roll. The sway bar is tunable by exchanging bars with different rates.

Front Suspension/Steering Overview:

• Front suspension/steering designed and built by Banks Race Shop

• Unequal length a-arm style

• Koni 2812 Mark II series double-adjustable coilover shock absorbers

• Eibach 500# 7”-long springs plus helper springs