1. Formula 1 Group Members: Quinn Collett Steve Godlewski Tobiah Halter Jeff Swanson Academic Advisor: Dr. Chien Wern June 4, 2003

2. Introduction Formula SAE is a competition focused on the design and fabrication of an affordable, weekend racecar. Performance and reliability are necessary attributes. Formula SAE is a competition focused on the design and fabrication of an affordable, weekend racecar. Performance and reliability are necessary attributes. As a Senior Project group we chose to design three major components of the car. As a Senior Project group we chose to design three major components of the car.

3. Project Scope Design, fabrication and testing of the three design components: Design, fabrication and testing of the three design components:  Hub Assemblies  Drivetrain  Aerodynamics

4. Decision Process  Product Design Specifications  External Search  Internal Search  Concept Evaluation

5. Presentation Outline  Rear Hub and Upright Design  Front Hub and Upright Design  Differential Housing and Drivetrain Design  Aerodynamics Design

6. Rear Hub and Upright Design

7. Components  Bearing Housing  Flanges  Connection Points  Angle Bracket  Bearings  Fasteners

8. Analysis of Hub  Material: 6061-T6 Aluminum  Yield Strength: 40 ksi  Factor of Safety: 3  Design Stress: 13.3 ksi  Results of FEA Analysis:  Max Von Mises Stress: 14.5 ksi  Maximum Displacement: 0.002 in

9. Analysis of Upright  Material: 6061-T6 Aluminum  Yield Strength: 40 ksi  Factor of Safety: 3  Design Stress: 13.3 ksi  Results of FEA Analysis  Max stress: 16.3 ksi  Max Deflection: 0.004 in

10. Verification PDS Criteria  Weight:  The hub assembly will weigh less than 17 lbs.  Hub=2.5 lb, Upright=4.5 lb, Total = 7 lb  Size/shape:  Components will fit within an 13 inch wheel.  It does fit.  Maintenance:  2 hour yearly overhaul  Maintenance free: sealed bearings, locktite on all screws  Installation:  Install in less than 120 min.  Can be done inside of an hour: press in bearings, 3 bolts per side  Cost (materials, bearings, bolts):  less than $400  Housing: $54.00, Hub: $186.94, Flange: $65.20, Connectors: $50.54, Angles: $1.34, Fasteners: $8.61, Bearings: $18.80  Total Cost of Materials: $385.43  Dynamic Testing  Has performed properly to this point

11. Front Hub/Upright  Design Criteria  PDS  30%-40% weight reduction over last years car  Ideal weight of 14 lbs.  Assembly fit within a 13 in. dia. Wheel  Handle loadings in race conditions  Incorporate connecting points for suspension and steering systems  Component Selection  Suspension Geometry  Steering Positioning  Brake Components  Bearing Selection

12. Front Hub/Upright  Analysis  Calculations  Track Conditions  Top speeds 60 mph/ Avg. Speed 30 mph  Safety Factors

13. Front Hub/Upright  Components  Hub assembly  Two piece design for ease of maintenance  Double row angular contact bearing ( axial and radial loads)  Upright  Spindle  Modeled using Solidworks®  Used to ensure fit  Compatibility with other components  Clearances and interference

14. Front Hub/Upright  Materials  6061-T6 Aluminum  304 Stainless Steel  Manufacturing  CNC Mill  Lathe  Press

15. Front Hub/Upright  Verification  Weight  Last years 32 lbs. This year 11.4 lbs.  64% weight reduction  Under Ideal weight of 14 lbs.  Track testing  Handles loads under acceleration, deceleration, and cornering  Problems/Improvements  Two Piece Separation  Spacers  Further Advanced Optimization  Weight reduction  Cost reduction

16. Drivetrain  Use of Common Parts  Honda CBR 600 F1  Limited Slip Differential  Use of Common Materials  4140 Steel  6061-T6 Aluminum

17. Rear Differential  Aluminum Housing  Zexel Torsen Limited Slip Differential  Sealed Bearings  Retain Gear Oil  Check Valve  Roll-Over and Tilt Protection

18. Power Transmission  Axle Shafts  4140-3/4” Steel  U-Joints  Drive Shaft  Splined Drive  Chain and Sprocket  Rear Mono-Brake

19. Drive Train Verification  Performance  Dyno-Testinig  Road Testing  Weight  Target 50 lbs  Manufacturing Time  Target 15 hours  Production Cost  Target $2000  Failures  Drive Axle Welds  Shielded Bearings  Changes?

20. Acceleration Torsion Testing

21. Aerodynamics & Body  Modeled using 3-D software package, SOLIDWORKS®  Forms CNC machined  Allowed for precision forming and exact fit  Material: 1/8” fiberglass mat w/ fine mat finish  Light weight and durable  Total Weight: 8.5 lbs.  Significantly below PDS target

22. Body & Aerodynamics con’t…  Estimated drag coefficient (C D ), front lift coefficient (C L ), drag force (D) and lift force (L)  C D = 0.14 D = 1.950 lbf  C L = 0.15 L = 0.910 lbf © 1992 SAE

23. Body & Aerodynamics con’t…  Estimated skin drag coefficient (C F ) and surface shear force per unit surface area (τ) (friction resistance)  C F = 4000τ = 901.87 lbf/ft 2 Source: Race Car Engineering, Katz

24. Body & Aerodynamics con’t…  Overall Performance Evaluation  Overall weight of car significantly minimized  PDS projected weight = 30 lb  Actual weight = 8.5 lb  Dimensions of car w/in 2% of desired  Drag force minimized as specified in PDS  Typical F-1 C D = 1.07  PSU Formula C D = 0.015  Lift force acceptable but could be further minimized by introducing further down force components which were sacrificed to make room for critical components (i.e. intake apparatus, radiator)  Typical F-1 C L = -0.99  PSU Formula C L = 0.015  Cooling performance maximized by channeling air over water-cooled components  average engine temperature w/o channeled air over radiator = 220°F  average engine temperature w/ channeled air over radiator = 200°F

25. Performance in Action