1. BHARATIYA VIDYA BHAVAN’S
SARDAR PATEL COLLEGE OF ENGINEERING
SPCE RACING
Reg. ID: 30469
Team Members
Sameer Kolte (C)
Parshva Shah
Amol Alsundkar
Chaitanya Joshi
Prashant Ramteke
Tushar Karande
Shweta Patil
Gaurav Munot
Pratik Baldota
Jaykishan Choksi
Akshay Jain
Priyank Gajiwala
Aniket Ghatvisave
Dhruv Phadke
Omkar Deshpande
Mukund Lahoti
Sanskar Panse
Nikhil Kotasthane
Sagar Dalvi
Siddhant Shah
Sumant Kherudkar
Presented By
Sameer Kolte, Aniket Ghatvisave,
Pratik Baldota, Parshva Shah, Priyank Gajiwala

2. Project Plan

3. Roll cage Design: Material and Cross Section Selection
Material Used: AISI 1018 Structural Steel
Property
Value
Ultimate Tensile Strength
460 MPa
Yield Strength
365 MPa
Density
7850 kg/m3
Young’s Modulus
2 x e11 N/m2
Poisson’s Ratio
Cross Section
Moment of Inertia (mm4)
Distance of extreme fibre (mm)
Section Modulus (mm3)
Area (mm2)
Circular
OD 1”
3mm Thick
12771
12.5
1022
207
OD 1.25”
2mm thick
20774
15.875
1308.5
187
Bracing: Circular cross section, OD =1”, pipe thickness= 2mm

4. Roll cage Design: Design Methodology
Objective: To provide minimal 3-D space surrounding the driver and ensure safety.
Driver’s measurements:
RRH design:

5. Roll cage Design: Design Methodology
RHO, SIM, FBM design :

6. Roll cage Design: Finite Element Analysis
Torsional Rigidity
Torsional rigidity: 2500Nm/deg
Stress Induced: 288MPa
Flexural Rigidity
Stress Induced: 107 MPa

7. Roll cage Design: Finite Element Analysis
Front Impact
Rear Impact
Rear Impact
Force=5G=17167N
Stress Induced= 123MPa
Front Impact:
Force=7G=24034N
Stress Induced= 319MPa
Side Impact
Side Impact
Force=3G=10300N
Stress Induced= 334MPa

8. Roll cage Design: Human Ergonomics
Side Impact Member Height: 9”; Kept close to minimum for less driver exit time.
Steering Wheel Position: Fixed according to driver comfort.
Driver Head Clearance: 7.5”; Kept greater than 6” as specified in rulebook.
RRH Inclination: 8 deg, fixed according to driver back leaning.
Width of chassis: Fixed such that there is clearance of 3” between any chassis member and driver body part.

9. Suspension, Steering and Brakes: Chosen Configuration
Type: Hydraulic disc brakes
Honda Aviator disc
Pulsar 220 calipers
Maruti 800 Master cylinder
Suspension:
Type: Double Wishbone unequal arm suspension (Front )
Double Wishbone, Twin outer ball joint suspension (Rear)
Coil Spring and Hydraulic damping
Steering:
Type: Ackerman Steering
Maruti 800 rack and pinion assembly

10. Brake System Human Foot force = 40kgf+ 20kgf(emergency)
Pedal Ratio = 4
Use of proportionate valve to achieve front: rear brake biasing.
Calculated stopping distance: 3.6metres

11. Suspension Design: Kinematics
Bump/Rebound travel: Front 200/-100, rear 200/-80 (mm) ; Roll angle: 5 degrees
Camber variation: Front: 0.85 deg/inch bump, 0.6 deg/deg roll
Rear: 1.34 deg/inch bump, 0.42 deg/deg roll
Static Data
Front
Rear
Camber angle
0 deg
Caster angle
7 deg
Toe angle
Kingpin angle
8 deg
6 deg
Scrub Radius
90mm
120mm
Caster Trail
23mm
0 mm
Roll centre height
400mm
396mm
Toe Variation: ZERO bump steer and Roll steer

12. Suspension design: Spring selection
Objective:
To achieve desired ground clearance of 12”
To achieve ‘oversteer’ while cornering.
Spring selection:
Rear springs: Maruti Zen Front struts
Measured spring stiffness ‘k’ = 21N/mm
Precompressive force= 140kgf
Front Springs: Inhouse designed springs
Target spring stiffness ‘k’ = 21N/mm

13. Wheel assembly components
Hubs:
Front hub: Designed hubs
Torsion and Bending
Braking Torque= 235Nm
Bending force= 1800N
Max Induced stress= 71MPa
Factor of safety= 6.5
Rear hub: Maruti 800 front hubs

14. Steering sub system Ackerman geometry C-factor = 37 mm/rev
Rack travel = 45mm
Wheel angles:
Inner= 43deg, Outer= 35deg
Minimum Turning radius= 4 metres

15. Maximum stress induced= 23 Mpa
Powertrain: Engine
Specifications:
Briggs and stratton 10bhp OHV engine
Torque: approx 18.75Nm at 2600 rpm
Power: 10bhp at 3600 rpm
Engine mounts:
Operating frequency range: 25 Hz to 70 Hz
Engine Mounts
Natural frequency= 460Hz
Maximum stress induced= 23 Mpa

16. Powertrain: Transmission
Schematic:
Engine-> CVT-> Reduction gearbox
Continuously Variable Transmission
1. CVTech CVT Ratio= 3.6:1 to 0.59:1
2. Comet 780 series= 3.75:1 to 0.6:1
Reduction gearbox
Constant reduction = 10:1
Final ratio= 36:1 to 5.9:1

17. Powertrain: Reduction
Differential
Input from CVT
Output to driveshafts
Total reduction: 11.45

18. Design Failure Modes And Effects Analysis (DFMEA)
Items
Potential Failure Mode
Potential Cause of Failure
Potential Effect Of Failure
Remedies to avert Failure
Chassis
Structural
Front/Rear/Side
Collision
Driver Injury, Chassis deformation, Damage to engine/suspension.
Incorporate bracing members, Nodal Structure, Use of Bumpers.
Fatigue
Resonance of engine frequency with chassis natural frequency.
Failure of welded joints
Use of rubber pad below engine, Incorporate bracing to increase natural frequency
Suspension
(A-Arms, Springs, Shock absorbers)
Bending, compression, Force due to anti dive;
Torsional shear failure of spring, Buckling
Permanent buckling of spring affects ground clearance;
Wishbone failure
Rear twin Ball joint suspension , High Factor of safety
Transmission
Mechanical
Cyclic loading, Radial loads due to CVT, Torsional shear stress in shafts
Gear failure, Shaft failure, Misalignment of shafts in gearbox
Use of standard shafts and gears, Bearings capable of taking high radial loads
Brakes
Brake fluid contamination, Bending of brake pedal, Bending of master cylinder rod
Brake system failure
Master cylinder cap, Brake Bleeding, High FOS for pedal, proper Master cylinder mounting

19. Safety Summary 5 point harness.
Battery placement: Away from rotating parts, Covered to prevent fuel spill on battery.
Front and rear bumpers to protect tie rod and toe link.
Master cylinder mount at height from base of chassis to prevent brake failure.
Resilient foam material on all pipes of cockpit.
Use of fire extinguisher.
Summary
Data
Value
Overall Length
90 inches
Overall height
58 inches
Track Width
Front: 52 inches
Rear : 50 inches
Wheelbase
66 inches
Gear Ratio
36:1 to 5.9:1
Estimated Weight of vehicle
Gross Weight : 350 kg
Kerb Weight : 290kg
Estimated Weight of chassis
55 kg with all mounts and welds

20. 3-D view of car