Circle Track Steering - Rack & Pinion

Racing Classes: Late Model & Dirt Late Model

Most Late Model and Dirt Late Model cars use special racing style rack & pinions (R&P) w/ power steering. These rack & pinion units are made by Appleton, Coleman, Sweet Mfg, and Woodward.

Standard R&P for use with Remote Servo	Integrated R&P w/ Servo
Remote Mount Servo

There are two types of rack & pinion units. Some setups have the steering servo remote mounted at the steering wheel end of the steering shaft or midway between the steering wheel and the rack & pinion. Some have an integrated servo that is part of the rack & pinion unit. The integrated servo style R&P is a little larger w/ the servo mounted on it, but requires fewer lines to hook up since two of the lines are already hooked up between the servo & rack.

These steering racks are measured in inches of travel for each turn of the steering wheel. This method is used since the steering ratio cannot be calculated by testing the steering rack & pinion all by itself. The steering ratio must be measured on a vehicle and changes based on other steering components besides the R&P (i.e. steering arm length, Ackerman steering, etc).

Racers generally want a quicker steering ratio on short tracks and slower steering on longer tracks. Dirt track racers usually want a very fast ratio for most short tracks (3" to 4" per turn). Asphalt racers also want a fast ratio, but not quite as fast (2" to 2-1/2" at most short tracks).

The steering servos are available in several sizes that range from .185 to .300. The lower numbers take the least amount of steering effort, and effort gets higher as the numbers go up. Changes in the servo change the feel of the steering, and .220 to .250 are the most popular sizes.

These steering racks are for use with front steer setups where the steering arm is on the front of the spindle. The R&P units use a 3-bolt mounting pattern and all use the same bolt pattern.

Typical Mounting Bracket

This bracket is normally welded to the front cross-member of the chassis that goes under the front of the engine. Billet Shims are often used between the R&P and the mounting bracket to make adjustments to eliminate bump steer. These shims are available in several thicknesses.

R&P Shims

Many racers use KRC power steering pumps, and these pumps have a unique feature that allows tuning of the steering system by changing the flow valve to fine tune the feel and assist in the power steering system.

For safety reasons, it is recommended that you use a collapsible steering column. You should also add a shaft collar on the steering shaft to limit upward movement toward the driver (mount it near one of the rod-end style Steering Shaft Supports).