Team UDFSAE: Suspension Group
David Zipf, Doug Corley, Josh Akell
Faculty Advisor: Dr. Steve Timmins
Sponsor: Jamie Gil
Master Machinist: Steve Beard, Jeff Rickets
Project Scope
Problem Background
Formula SAE® is a student design competition organized
by SAE International (formerly Society of Automotive
Engineers).
Concept is that a fictional manufacturing company has
contracted a design team to develop a small Formula-style
race car.
 Target marketing group for the race car is the nonprofessional weekend autocross racer.
Student team designs, builds and tests a prototype based
on a series of rules to ensure safe operation and clever
problem solving.
To design and fabricate all suspension components, including the front and rear A-arms,
uprights, front hubs, mounting points, push rods and rockers, tie rods, spring and shock locations,
control arm clevises, sway bar system and steering rods. Suspension must conform to FSAE
rules and have wide range of adjustability
Front Suspension
Glossary of Terms
Rear Suspension
Design Detail
Evaluated and optimized using kinematic and force analysis.
Measures of performance include bump steer and roll center movement.
Mounting
Upright Clevis
Changed from steel to aluminum mounts, halved weight.
Rear includes integrated toe link mount
Key Metrics and Targets
Metric
Target Value
Wheel Base
60”
Spring Rate
~ 350 lbs./in (adjustable)
Track Width
50” (front/rear)
Dynamic Wheel Travel
2.0”
Minimum Turning Circle
⌀ 20 feet
Camber
-1.5° (static), minimal gain
Ease of Camber/Toe
Adjustment
Scrub Radius
Adjustment w/o removal of wheel/hub
Roll Center
High as possible without causing jacking.
Bump Steer
≤ 1/16”/inch vertical deflection
Cost
< $1000
Caster Angle
4°
Ride Height
2.5” from lowest point of car
System Weight
<30 lbs/corner with wheel & tire
0.5”
Chassis Clevis
 Designed to undergo forces seen in a combination of hitting a bump, braking, and
cornering (5G vertical and 5G towards center of car, simulates extreme combined
bump and corner loads).
Adjustability in the wheel rate and spring rate was critical and can be adjusted by
changing the sway bars’ pickup points.
Bolted on steel. Shims allow
alignment changes without removal
of wheel. Camber, caster, and KPA
can be adjusted this way
Pushrods
Made from welded steel. Designed to withstand combined
5G bump impact and cornering load
FBD of forces in suspension
FEA of rocker
Sketch of steering arms
Front Pushrod Mount
Rear Pushrod Mount