The document provides technical details of a BAJA SAE vehicle designed by Team Piranha Racing from Maharashtra Institute of Technology, Pune. It includes dimensions, materials, and analysis results for components like the roll cage, suspension, transmission, brakes, and steering. Graphs show performance parameters like acceleration, traction forces, and steering characteristics. The document also outlines the project plan, workshop facilities, cost breakdown, and validation methods like a half-car model analysis of camber and roll center heights.

1. Virtual BAJA SAEINDIA 2014
Team Name Piranha Racing
Team ID 14127
Maharashtra Institute of Technology,
Pune
Wheel base 58”
Wheel Track 50”
Vehicle Height 1.58m
Height of C.G. 22”
Ground Clearance 13”
Roll Cage Material
O.D.
Thickness
AISI 4130
1.125”
0.095”
Total Length of Pipe 39.23m
Weld Length 3.45m

2. Roll Cage - Analysis
Front Impact
Stress:
216.6MPa
Side Impact
Pre Stress:
446.2MPa
Side Impact
Post Stress:
365.1MPa
Roll Analysis
Stress:
64.67MPa
Torsional
Stress:
156.6MPa
Rear Impact
Stress:
171.7MPa

3. CVT- Polaris P85 Belt CVT
Reduction
Gear Drive:
Compound Planetary Differential
• Epicyclic gear train is
used as differential with
no speed reduction.
• Fixed – Ring gear
• Input – Flange
• Output 1 – Sun 1
• Output 2 – Sun 2
ω(out) = ω(in) x 7
Reverse
Gear
Train
CVT
Input
Differential
CVT ratio=R1/R2
0.78 3.84
Shaft
• Self-designed
• Material: 16Mn5Cr4
Dia=22 mm
Transmission
CVT Output
R2=115 mm
Engine Input
R1=95 mm
• Gear Ratio = 7
• Works as FNR
Kings KT 102 Traction
Dimension(mm): 22x8x10
Wheel

4. 0.000
0.500
1.000
1.500
2.000
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
50.00
55.00
60.00
ACCELERATION v/s ROAD
SPEED
Engine
(rpm)
Power
(w)
Gear
Ratio
Traction
(N)
Air Drag
(N)
Inertia
(N)
Velocity
(m/s)
Acceleration
(m/s2
)
Gradability
2000 3730.00 25.08857 1600 1.650798193 1045.436 7.55325 1.485838009 31.85770558
2400 4699.80 23.89388 1600 2.620807212 986.9174 9.517095 1.572957555 31.83547437
2800 5445.80 24.05753 1600 3.518841429 994.765 11.027745 1.55964594 31.81489748
3200 6117.20 24.47666 1600 4.439986821 1015.107 12.38733 1.527484809 31.79379581
3600 6714.00 25.08857 1600 5.348586146 1045.436 13.59585 1.482300934 31.77298626
3800 6863.20 25.90668 1600 5.588942363 1087.156 13.89798 1.425196698 31.76748219
3800 6863.20 21.04918 1300 8.466090207 859.0678 17.105206 1.451030902 25.05948271
3800 6863.20 17.81084 1100 11.82453922 733.2261 20.215244 1.422720129 20.76034664
3800 6863.20 14.57251 900 17.66381784 628.3579 24.70752 1.332578354 16.53003386
3800 6863.20 9.715004 600 39.74359014 510.3813 37.06128 1.009551889 10.08323425
3800 6863.20 8.095837 500 57.2307698 481.5426 44.473536 0.826031286 7.767741583
3800 6863.20 6.667602 411.792 104.1666667 460.4569 60 0.57035811 5.119730408
0
200
400
600
800
1000
1200
1400
1600
1800
7.55325 13.89798 44.473536
AIR DRAG (N)
TRACTION VS
VELOCITY
INERTIA
ROLLING
RESISTANCE
FORCES v/s VELOCITY 0
1000
2000
3000
4000
7.55325 13.89798 44.473536
ENGINE RPM v/s VELOCITY
ENGINE…
Transmission
Briggs & Stratton Model 20 Specifications:
Displacement 305 cm3
Bore x stroke 79.25 mm x 61.93 mm
Compression Ratio 8:1
Max. Power 7.5 kW @ 4000 rpm
Max. Torque 25.18 Nm @ 2200 rpm

5. PARAMETER FRONT REAR
Suspension Type
Double
Wishbone
McPherson
Strut
Natural Frequency 2.23 Hz 2.29 Hz
Stiffness 11.8 N/mm 32.38 N/mm
Damping Ratio 0.35 0.35
Wishbone Material AISI 4130 AISI 4130
Max. Suspension Travel 127 mm 74 mm
Transmissibility Ratio < 2.5
Spring Material
SUP 7C
Steel
SUP 7C
Steel
Toppling Speed
(at min. turning radius)
20.3 kmph
Roll Gradient 5.19 deg/g
Sprung Mass 300 Kg
Un-sprung Mass 50 Kg
Pitch Frequency 1.79 Hz
Bounce Frequency 1.64 Hz
Camber Angle Variation -2.80 – 30
Suspension
CAMBER
ANGLE
VARIATION
SUSPENSION
GRAPHS

6. FEA of Critical Components
Wheel
Assembly
Wheel
Assembly
exploded
view

7. Steering
Ackerman Steering Geometry
(Rack & Pinion System)
Wheel Base (L) 58”
Pivot to Pivot distance (t) 42”
Kingpin Inclination 7⁰
Caster Angle 3⁰
Camber Angle
0⁰ to 0.5⁰
(+ve)
Toe Angle 0⁰
Scrub Radius 24 mm
Steering Arm Length 120 mm
Rack & Pinion
Steering Ratio 8:1
Rack Travel
(lock to lock)
4.25”
Steering Wheel Diameter 14”
Extreme
Turning Angle
Inside 35⁰
Outside 23.57⁰
Steer Angle Error (max) 2⁰
Minimum Turning Radius 2.77m
Characteristic Speed 77kmph
Parameter Value
Length of Tie
Rod
12.97”
Assumed O.D. 15mm
Calculated I.D. 12.82mm
Material AISI 1026
0
10
20
30
40
0 20 40 60 80
Y
a
w
G
a
i
n
Velocity (kmph)
Yaw Gain v/s Velocity
0
5
10
15
20
25
30
35
0 20 40 60 80
S
t
e
e
r
A
n
g
l
e Velocity (Kmph)
Steer angle v/s
Velocity
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
10 20 30 40 50 60
Lateral Acceleration
Gain v/s Velocity

8. Disc and
Caliper
assembly
Brakes
• Hydraulically actuated disc brakes on all wheels.
• Two different pedal designs (offering left/right foot flexibility).
• 200mm petal discs (SS304) with floating caliper.
Pedal and
Master
Cylinder
assembly
Part Specifications
Master Cylinder M800 (Bosch) Bore 19.05 mm
Hose STD 3/16”
Caliper
Apache 150 &
Suzuki GS
2 POT
Bore 26 mm
Disc
TVS Apache RTR
180 Rear Disk
200 mm OD
120 mm ID
Performance Parameters Value
Perception Distance 16.66 m
Total Braking Force 1024 N
Deceleration 8.812 m/s2
Stopping Distance (60kmph) 13.4 m
Max. Dynamic wt. Front Axle 2200 N
Min. Dynamic wt. Rear Axle 1233.61 N
% Weight transfer 34 %
Bias Ratio (Front : Rear) 16 : 9
Design
Parameters
Value
Pedal Force 100 N
Leverage
(Pedal Ratio)
6:1
Piston Ratio 3.75
Braking Torque
(per wheel)
71.9 Nm
Proportioning
valves
TMC

9. Innovation
Event
Desired
Sensitivity
Pedal rotation
for Max Accn
(X)
Ra
(KΩ)
Ra=R1+Rp
Rb
(KΩ)
C
(μF)
R1 Rp 00 X0
Acceleration High 120 4.0 4.0 4.0 8.0 76 – 72 0.361
Endurance Medium 180 6.0 6.0 6.0 12.0 114 – 108 0.241
Maneuverability Low 240 8.0 8.0 8.0 16.0 152 – 144 0.180
Rack &
Pinion
Accelerator
Pedal
Electronic Throttle Control System
Max.
Pedal
Travel=
300
300
IC 7806

10. Ergonomics & Electrical
Hand Reach Envelope
Vision Cone
Reach
Limit &
Visibility

11. Infrared Emitter Infrared Sensor
Safety
ABC Grade
0.5 kg Fire
extinguisher
INFRARED
EMITTER

12. Component Potential Failure Mode
Potential
Causes/
Mechanism of
Failure
Potential Effects of
Failure
O S D RPN Recommended Action
• Gearbox
Provides
variable
torque and
speed to
lower power
train.
• Enables
effective
conversion
of engine
power
according to
variable
loads
Surface
Wear
Abrasive
Wear
Foreign particles
in lubricant
Lapped finish; radial
scratch marks;
grooves on contacting
surfaces
1 6 7 42
Oil filters; high viscosity oils;
gear enclosure; regular
replacement of oil; increase in
surface hardness
Corrosive
Wear
Chemical action
of active
ingredients in
lubricant
Fine uniform wear 1 6 7 42
Proper selection of lubricant;
regular check-up and
replacement of oil
Initial Pitting
Tooth profile
errors; surface
irregularity;
misalignment
Redistribution of loads
due to progressive
removal of high
contact spots
1 7 4 28
Precise machining and
alignment;
Destructive
Pitting
Loads > surface
endurance
strength of
material
Complete destruction
of tooth surface and
premature breaking
3 8 3 72
Design gears for wear strength
> (static + dynamic) loads;
increase surface hardness
Scoring
Overheating due
to excessive
frictional heat
Alternate welding and
shearing
2 6 4 48
Adjusting surface parameters to
reduce working temp.; proper air
and lubricant circulation
Breakage
Fatigue
Failure
Root stress >
endurance limit of
material
Fretting and breach
marks; breakage of
part or whole tooth
2 8 2 32
Design for reduced stresses;
polishing and shot-peening of
root fillet
Overload
Breakage
Sudden overloads
> tensile strength
of material
Stringy fibrous break
(pulled or torn apart
abruptly)
2 8 2 32
Design with greater factor of
safety, and higher value of
service factor.
DFMEA

13. Project Plan & Team Distribution
TeamDistribution(25)
Steering 1BE, 2TE
Suspension 2TE
Transmission 2BE, 2TE
CAD/CAE 1BE
Brakes 1BE, 1TE
Electrical 2SE
Innovation 3SE
Cat-Con 1BE, 1SE
Marketing/Project
Planning
2SE
Aesthetics/
Ergonomics
2SE
Safety 2SE

14. Workshop Facilities & Technical
Components
Facilities Technical
Components
Quantity Unit Cost (INR) Total Cost (INR)
Engine 1 20000 20000
Gear Box 1 20000 20000
CVT 1 80000 80000
Steering Rack 1 7000 7000
Hub 4 5000 20000
Knuckle 4 6000 24000
Brake Calliper 4 2500 10000
Brake Disc 4 500 2000
Shafts 2 2700 5400
Shock Absorbers 4 4500 18000
Battery 1 3000 3000
Kill Switches 2 2000 4000
Steering Column 1 1800 1800
Servo Motor 1 2800 2800
Grand Total = 218000
• Weight of Vehicle with Driver: 350 Kgs
• Finance Budget: INR 3.5 Lakh

15. Design Validation
Camber Angle Variation v/s Wheel Travel Roll Centre Height v/s Wheel Travel
Half Car Model

16. Thanks
Vehicle completion Date:
18 January 2014
Vehicle Inspection Date:
22 January 2014
Our Sponsor
M.I.T. Pune
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