Saad Qureshi led a 10-week project to convert two Baja race cars into Auto-Cross cars. He refurbished parts and purchased missing components for the first phase. For the second phase, he redesigned the suspension and engine mounts to lower the vehicles and improve handling for Auto-Cross racing. Saad created CAD models, collaborated on suspension design, welded new components, and tested the vehicles on a dynamometer to generate an engine power curve.

1. Project Overview and Contributions From Saad Qureshi
September 2008 – January 2009

2. The Challenge: Convert 2 previously built Baja
race cars into Auto-Cross race cars
Project timeframe: 10 weeks for 2 design phases
Mod 1 – Refurbish cars for public and university
demos
Involved fixing / re-fabricating broken parts and
purchasing missing parts
Acquire vehicle data – No previous design data
available for these cars
Mod 2 – Redesign for Auto-Cross racing
Adjust and lower suspension, design new engine
mount, modify chassis
Evaluate performance of new vehicles

3. Vehicle 1 – Codename “Alpha”
Alpha Vehicle SolidWorks
Assembly – Mod 1

4. Vehicle 2 – Codename “Beta”
Beta Vehicle SolidWorks
Assembly – Mod 1

5. Design – Started on Beta team
Created new CAD files for Chassis and Engine Mount on
Beta Vehicle
Collaborated with suspension engineers to raise
suspension mounts, reduce suspension travel, and shorten
track length
Manufacturing – Moved to Alpha team
Profiled metal and MIG welded control arms, steering
mount
Testing – Both vehicles
Configured and setup Mustang Dynamometer
Troubleshooted chain pop-off issues
Generated Briggs & Stratton engine power curve

6. Dimension current Beta vehicle chassis into a
SolidWorks subassembly
Gather initial vehicle dimensions
Design chassis subassembly to facilitate additional
changes:
Location of new impact attenuator/ Bumper
How high rear suspension mounts should be lifted to lower
the car
Required chassis adjustments to stretch the wheelbase by
1.5 inch
New areas requiring welding to raise the pedal mounts
Adjustments on steering linkage to correct issues with U-
joints

7. Front

8. Middle

9. Rear

12. From concept to reality:
Suspension
Assembly
Control Arms
1
3
2

13. Dynamometer Issues:
Windows 95 era software – minimal instructions
Legacy ISO slot – hardware data capture nonfunctional
Current engine mount incorrectly sized
No software control over engine speed
Chain pop-off above 3000 RPM
Less than 10 days to:
Configure and calibrate software
Modify engine mount and exhaust
Troubleshoot chain pop off issues
Generate engine power curve

14. Increased chain length to
give space for 10 HP Briggs
& Stratton model 205432
Mounted external fan for
cooling
Harnessed exhaust duct
next to engine

15. Consulted with other engineers to design a chain
tensioner and guide using nylon spacers
Profiled and welded clutch end chain guides:
Problem solved!
Finished testing over entire engine operating range

16. Ran individual tests at 1000 RPM intervals
Used spreadsheet software to manually generate
curves from raw data
Mod 2 Engine Power Curve
25.0
20.0 Engine Speed (RPM) Torque (ft-lb) Power (HP)
2400 18.0 8.2
2500 18.5 8.9
15.0
2600 20.5 10.2
Power
Torque (ft-lb)
Power (HP)
2700 20.7 10.7
10.0 2800 20.9 11.2
2900 20.6 11.4
5.0 3000 19.8 11.6
3100 19.7 11.7
3200 19.7 12.1
0.0
3300 19.4 12.2
2000 2200 2400 2600 2800 3000 3200 3400 3600 3800 3400 18.3 11.9
Engine Speed (RPM) 3500 16.5 11.0
3600 9.0 6.2