Project by:

Team Thunderbirds(SAE BAJA 2015)

Thunderbirds set out to design and constructan all-terrain utility vehicle. The team’s vehiclethe trendnought ,has two treads to allow it totraverse a wide variety of terrains such assnow, mud ,grass and gravel.

BRIGGS AND STRATTONBriggs & Stratton is the world's largest manufacturer of air-cooled gasoline engines primarily for outdoor power equipment. Current production averages 11 million engines per year.

Briggs & Stratton engines are commonly used on lawnmowers.

Displacement [cc] = 306

Bore [mm] = 82

Stroke [mm] = 58

Weight [kg] = 25

Oil Capacity = 1.1

Compression Ratio = 8.0 to 1

MAHINDRA ALFA

The Alfa is a three wheeler goods carrierdesigned to make the loading, transportation,and unloading of small cargos easier.

Mahindra equipped the Alfa with the largestand strongest cargo box yet at 24.5 cubicfeet, and then adapted the structure tohandle oversize loads.

Engine Type = 4-stroke, Single Cylinder, air cooled diesel engine

Displacement = 395.00 CC

Maximum Power = 5.51 KW @ 3600 rpm

Maxiumum Torque = 16.7 Nm @ 2200-2800 rpm

MaxSpeed = 53 Kmph

Transmission = Constant Mesh

Clutch = Multi Plate Wet Clutch

Gearbox = 4-speed

Mechanical The engine and power train option that was considered was a mechanical gearing system powered by an internal combustion engine. While the mechanical system can’t provide the zero-turn capabilities as simply as hydraulic or electric systems can.

Primary gear ratio=2.86

Secondary gear ratio=2.38

Final gear ratio=primary gear ratio*secondary gear ratio*individual gear ratio

Gear Individual Gear ratio Final gear ratio

1 4.62

31.45

2 2.75

18.70

3 1.67

11.40

4 1.08

7.35

Reverse 8.09

55.05

TORQUE=Maximum torque by engine*final gear ratio

Gear Torque(N)

1 587.80

2 349.50

3 213.06

4 137.37

5 1028.88

Radius of wheel=0.317m

Force on wheel=torque/radius

Gear Torque(N) Radius(m) Force(N)

1 587.80 .317 1854.25

2 349.50 .317 1102.52

3 213.07 .317 617.94

4 137.37 .317 433.34

Reverse 1028.88 .317 3245.67

RPM =Engine rpm/final gear ratio of different gear engine rpm=3800

Gear Engine rpm Final gear ratio rpm Rps=rpm/60

1 3800 31.45 120.82 2.01

2 3800 18.70 203.20 3.38

3 3800 11.40 333.33 5.55

4 3800 7.35 517.00 8.61

reverse 3800 55.05 69.02 1.15

Circumference=2𝝅r

r=0.314

Gear Speed=rps*2 pie r in m/s

1 4.07

2 6.74

3 11.05

4 17.15

Reverse 2.28

Aerodynamic drag=0.5 *p*A*V*Cd

A=frontal area of vehicle=1.0966

Cd=coefficient of drag=0.6

Gear Aerodynamic drag

1 6.33

2 17.93

3 48.27

4 116.13

Rolling resistance =mg*Crr

m=mass of vehicle=250kg

g=accelaration due to gravity

coefficient of rolling resistance=0.15

total resistance =drag+rolling resistance

Gear Rolling resistance Aerodynamic

resistance

Total resistance

1 367.5 6.33 373.83

2 367.5 17.93 385.43

3 367.5 48.27 415.77

4 367.5 116.13 483.63

Tractive force =force on wheel-total resistance

Gear Force on wheel(N) Total resistance Tractive force(N)

1 1854.25 373.83 1480.42

2 1102.53 385.43 717.10

3 617.94 415.77 202.17

4 433.34 483.63 50.34

Acceleration=tractive force/weight of vehicle

Gear Tractive force Acceleration Time taken

1 1480.42 6.02 0.66

2 717.10 3.02 2.32

3 202.17 1.16 4.36

4 50.34 1.08 11.34

Components Cost

Frame & Body 40,000-/

Suspension 20,000-/

Wheels & Tires 50,000-/

Steering 10,000-/

Breaks 15000-/

Engine & gearbox 60000-/

Instruments & wiring 10000-/

Driver accessories 50,000-/

Logistics & travel 40,000-/

Promotion & merchandise 20,000-/

Competition fees 50,000-/

Total 3,65,000-/

Engine & gear

Total Rs3,65,000

Components Cost

B&S Engine 35,000

Transmission 19,000

Labour Cost 6,000

Total 60,000

Engine & Gearbox:Standard B&S engine, Mahindra Alpha Transmission.

It is used to get various speeds in different load conditions.

It increases fuel efficiency. Increases engine efficiency. Need less power input when operated manually. They are more practical when there is a space

limitation.

Robust transmission and longer gearbox life.

Best suited for Briggs and Stratton engine.

Compact and easily available in the market.

Data of Specification and features are easily available.

www.bajasaeindia.org/

www.irdindia.in/journal_ijmer/pdf/vol1_iss1/17

www.mahindrasmallcv.com/bolero_alfa_passenger_diesel

www.grabcad.com/library/briggs-and-stratton-10hp-engine-for-baja-sae

www.briggsandstratton.com

www.mahindrajhbsouth.co.za/mahindra-alfa-specifications/

grabcad.com/library/mahindra-alfa-champion-gearbox-1

Thank you!