TR23 Steering Rack

Two problems with the previous rack: steering effort was too high, and assembly was painful. The drivers were complaining and the pit was losing time.

Effort. Swapped the pinion from 24-tooth to 27-tooth — moved the gear ratio toward lighter steering at the wheel.

Assembly + backlash control. Designed two CNC-machinable shells that let the team tune the distance between rack and pinion in assembly — backlash becomes adjustable instead of being a roll-of-the-dice on tolerance stack-up.

Big innovation. Pulled the steel rack and pinion to 7075-T6 aluminum, anodized. 7075 trades durability for weight — but the rack only has to survive a 4-hour endurance race, so the math works.

Lower steering effort, real backlash control, and a meaningful weight reduction at a part that's high in the suspension chain (every gram saved here helps unsprung mass and steering feel).

• If the part has a defined service life (4-hour race, not a million-cycle field deployment), match the material choice to that life. Don't over-spec.
• Designing tunability into a manufactured part beats designing for one perfect tolerance — the team can dial-in at the bench instead of binning parts that came back at the wrong end of the spec.