The front anti-roll bar torsion element.
Present on CR21 and CR26E, deleted on CR26I for packaging. See the Center Torsion Bar (Front) entry for the consequences. Design Philosophies and Processes: Inherited from the ARB subsystem design process: 1. Take the roll rate targets and the LLTD range from vehicle dynamics. 2. Size the torsion bar. CR26I: AISI 4130, 0.5 in OD, 0.33 in ID, 68.12 lb-in/deg torsional stiffness, contributing 1160 lb-in/deg (96.7 lb-ft/deg) to roll rate at nominal. 3. Design the blade and set the drop link positions. Five settings give blade lengths from 4.43 in to 5.57 in and roll rate contributions from 113.8 down to 72 lb-ft/deg. 4. FEA the blade at each setting to confirm deflection and the resulting change in roll rate contribution (1.24% to 1.34% across the range). 5. Design retention: a machined square boss and bore to minimise backlash, a threaded stud for blade retention, and a transition-fit needle bearing for bar mounting. 6. Confirm the resulting LLTD range on the car.
AISI 4130 steel.
None recorded. This part has no entry in Knowledge_Transfer/Issue Logging/Fault Vault.xlsx, in either Issue Log.xlsx, in CR22/Issue Tracking/Shakedown 7-15-23.xlsx, or in any design review issue list found in CrimsonStorage or Box.
Dimensions called out on the cost report drawings. These are the figures printed on the drawing, not a labelled specification; open the drawing itself for what each one refers to. Front ARB Torsion Bar (as drawn): 91.36, 9.14, 25.45, 2.55, 335.28, 33.53, 259.08, 25.91, 44.45, 4.45 Source: Cost report drawings: CR22/Document Submissions/Cost Report/Suspension/Cost Report Drawings/Suspension & Shocks/Front ARB Torsion Bar/Front ARB Torsion Bar.pdf; CR22/Suspension/Design/01_Cost_Report/Cost Report Drawings/Suspension & Shocks/Front ARB Torsion Bar/Front ARB Torsion Bar.pdf
Nothing in CrimsonStorage covers these yet.