1970 lotus europa front suspension redesign
DESCRIPTION
1970 Lotus Europa Front Suspension Redesign. ME 462 Capstone Design Spring 2007 Sponsor: Bishop Steering Technology Kel Tiedman, Jason Wou. Team Members. Tom Filipucci Frank Faulkenberg. Brian Schludecker David Giles. May 3, 2007. Project Background. - PowerPoint PPT PresentationTRANSCRIPT
1970 Lotus Europa Front Suspension Redesign
ME 462 Capstone Design
Spring 2007
Sponsor: Bishop Steering Technology
Kel Tiedman, Jason Wou
Tom Filipucci
Frank Faulkenberg
Brian Schludecker
David Giles
Team Members
May 3, 2007
Project Background
1970 Lotus Europa 1470cc, 4-cylinder engine producing 78 hp
120 mph top speed
13-inch wheels
2-piece control arms Stamped & welded Bolt-on ball joints
Coil-over shock & spring arrangement
Customer Requirements
Maintain suspension geometry
Provide stable 200 mph ride
Maintain 5 inch ride height
Utilize 15 inch Audi wheels
Utilize current frame mounting points
Maintain wheel-to-wheel dimension
Attempt to utilize stock shock and spring size
Minimal bodywork modifications
Engineering Targets
Engineering Requirements Target Units
Scrub Radius 10 mm
Roll Center Height 50-100 mm
Car Ride Height 5 in
Anti-Dive 25 %
Steering Axis Inclination 7 deg
Caster Angle 4 deg
Camber Angle -0.5 deg
Caster Trail 15-35 mm
Final Design
Final Design
Upper Arm = 5.60 in Lower Arm = 11.03 in Scrub = 10 mm Steering Axis = 16.5º Rotor Clearance = 0.69 in
Design Animation
Design Animation
Design Evaluation
Suspension Analysis Four-bar
Mechanism
Design Evaluation
“Fourbar” Program – Norton Evaluate each control arm length iteration
Rough wheel motion
“Four-bar Mechanism” - Matlab Quantitative wheel motion
ProEngineer Mechanism output to Excel
“Camber Curve” - Matlab Camber curve comparison
Design Evaluation
Iteration Method2 Iteration Sets
First Set – 11 possibilities Manipulated Variables
Scrub radius Steering axis
Second Set – 6 possibilities Same Variables
Smaller scrub radii Larger steering axes
Design Evaluation
Case 5: Steering Axis – 16.5° Scrub radius – 10.0 mm Upper arm – 5.60 in Lower arm – 11.03 in
Case 1: Steering Axis – 16.0° Scrub radius – 11.0 mm Upper arm – 5.70 in Lower arm – 11.04 in
Design Evaluation
Design Evaluation
-6 -5 -4 -3 -2 -1 0 1-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
Degree
Ver
tical
Whe
el T
rave
lCamber Curve Comparsion
Case 5
Case 1Zero scrub/ 20 Degree steering axis
35 mm scrub/ 7 Degree steering axis
FEA Results
Final Evaluation
Engineering Requirements Target Result Goal Met
Scrub Radius 10 mm 10 mm
Roll Center Height 50-100 mm 50.8 mm
Car Ride Height 5 in 5 in
Anti-Dive 25% 25%
Steering Axis Inclination 7º 16.5º
Caster Angle 4º 12º
Camber Angle -0.5º -0.5º
Caster Trail 15-35 mm 25 mm
Conclusion & Recommendations
Conclusion Kinematic motion requirements met Verified some physical packaging requirements
Recommendations Further finalization of arm shapes In-depth finite element analysis Close examination of control arms and knuckle attachment One team for knuckle/brake and suspension design
Questions?