Formula Manipal Report

SUBMITTED BY: Siddhartha Jain, MIT Manipal

Formula Manipal Project Report

Department of Mechanical and Manufacturing Manufacturing

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ACKNOWLEDGEMENT We express our sincere gratitude to Mr. B Vijayakumar, Managing Director – L G Balakrishnan and Bros. for giving us the opportunity of undertaking this project at his facility. We thank all technicians, foreman and executives for explaining the practical aspects of theoretical knowledge that we have acquired at our college. Working at LG Sports, we were exposed to a wide array of technical detail, in the field of race car engineering. Having access to India’s only Formula – 3 certified tracks, helped us do extensive testing on our prototype and hence optimize its design and performance. We would also like to take this opportunity to thank all our sponsors, without whom the project would not have been possible. Their constant encouragement and morale boosting support made it possible for us to represent India and our University at the world’s toughest engineering design competition. We would like to thank Dr. Ranjan Pai, CEO MEMG, for being one of the first people in the industry to believe in our potential and funding us to a great extent. As a team, we would also like to sincerely thank Dr. N Y Sharma; without whose vision and belief in our capabilities this project would not have taken off. It was due to his constant guidance and indomitable support, that a project of this scale was possible. We would ever remain indebted to him, for all what he has done to make our dream project become a reality. We take the opportunity to specially thank: Mr. Leela Krishnan, Mr. Narain Karthikeyan, Mr. Sanjay Sharma, Mr. C Rajaram for their kind support and encouragement at every point of the training, in the form of this project, without which this would not have been successful.


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PREFACE With the relentless improvements in technology the older machinery are being replaced by new machinery. The handling of such highly sophisticated machines, no longer remains the work of a semi skilled person. It has opened a new horizon for young graduate engineers. But to contribute in an efficient and meaningful manner towards completion of the assigned task, at the industry, suitable training is needed. The knowledge of the system, as a whole, is a must for an engineer to do the trouble shooting in the smallest possible time so that production is not affected. Therefore, industrial training plays a vital role in developing practical knowledge. Thus, industrial training is not only an academic requirement but a professional necessity too. I’ am honored to have been a part of the team, which built Manipal University’s first Formula Society of Automotive Engineers (FSAE) race car. This project, as a part of one of the first projects of the University under the Conceive, Design, Implement and Operate (CDIO) paradigm served as the platform for rigorous industrial training for the team members. The car was built at the work shop of Indian racing enthusiast Mr. B Vijayakumar at the Kari Motor Speedway in Coimbatore. In this practical training report I have tried my best to introduce and explain all the important sections of the massive project, of which I have ha ve been a part for the past two and a half ha lf years.


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INTRODUCTION The principle objective of Formula SAE-A is for students to conceive, design, build and compete with a small open wheel race car. The restrictions on the car are designed to maximize the use of the student’s imagination and knowledge, and to give the students a meaningful project as well as good practice working in a team environment. The car is to be designed to maximize its acceleration, handling and braking. The maximum speed is kept to about 100kph by the track layout. The car needs to be easy to maintain, low in cost and reliable. The design brief is for a prototype of a car that is intended to be made as a production item for non-professional weekend autocross racers. As such the prototype should cost less than $25000. The challenge is to design and build a car that best meets these requirements that will then be compared with the other competing designs to determine the best overall vehicle. Being a first year team, and also a lso one amongst very few Indian teams participating in FSAE, Formula Manipal has faced its fair share of obstacles in the fields of design and engineering. Most of our initial design plans have been modified, if not completely revamped, as we came to understand unde rstand practical engineering. The formulation of our o ur first car, the FM 08, is a compromise between ideal designing and the limitations of manufacturing. FSAE relies entirely on an applied knowledge of mechanical, electrical elec trical and electronic systems. The completed product p roduct of o f our ou r efforts is thus an FSAE vehicle built with the idea of optimum o ptimum performance at a market‐friendly cost and reliability. We look to fulfill our design goals by providing a car which retains its simplicity of use, while still offering considerable power. Formula Manipal also looks to this car as a medium by which we, as students, gain confidence and knowledge in the all‐encompassing field of automotive race‐car engineering. My project aim is to undertake the design and development of various component of Formula SAE racing car that will optimize performance and reliability whilst minimizing cost and weight. The design must meet all Formula SAE-A rules and regulations including all safety features. This report describes various design process, calculation and decisions taken during the fabrication of FSAE car. It also includes manufacturing of few of the critical components installed in the car.


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Spaceframe:

The design of a chassis for a formula SAE-A race car must contain all

necessary components to support the car and the driver. It must also comply with the formula SAE 2008 rules. In order to produce a competitive vehicle with optimum chassis performance, many areas need to be studied and tested. A space‐frame was chosen over monocoque construction to allow for a simple reparation process and ease of manufacture in a limited facility workshop. Our spaceframe was entirely fabricated from round tubular steel members to provide a torsionally ridged chassis frame. This process involves more complicated fabrication techniques as precision notching is required to achieve a strong structural join. These joining methods have been made much easier for hardened steels with the introduction of high quality tooling. The joining of two round tubes through notching also increases the amount of weld area increasing the strength. Initial space frame was fabricated in TEBMA shipyard. However, after consulting experts, we realized it does not enough strength and hence a new spaceframe was fabricated at LGB Sports.


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Drivetrain: The transmission, also referred to as the drive-train, is that part of the race-car which transfers power from the engine crankshaft to the wheels. The power produced at the crankshaft is at an rpm too high for direct transmission to the wheels. Hence, it is the drive-train system which decides the most efficient “gearing down” of this speed. The drive-train system of the car technically also includes the gear box. However, the selection of a Honda CBR R600 engine meant that a gear-box would come attached with the engine itself. As a first-year team, the initial design decision with regard to transmission was to not touch the gearbox itself. Hence, the gear-box of the Honda engine has not been included in any further discussions. For the purpose of simplicity, we consider the drive-train to be the system which transfers rotary power from the front sprocket of the engine (attached to the end of the gearbox) to the wheels. Thus task ahead of the transmission team was to decide the differential to be used, designed the sprocket that has to be connected to the differential for power transmission and differential mountings. With a study of available options for differentials, we had to make an educated selection from a Torque-biasing Differential, Clutch-pack Limited Slip Differential, Open Differential and Spool Differential. We have opted for a Taylor Race Torque-biasing Differential for implementation in our first-year vehicle. With the TRE model, we do d o not have to design housing by ourselves a task acknowledged as very risky by most veterans of the competition. The TRE differential offers torque biasing at a theoretical ratio of 4:1 Tripod CV-joints are used on hollow shafts with plastic fillers. Using a 14 tooth drive sprocket, a chain-sprocket system has been incorporated. A custom designed 46 tooth rear sprocket is being used which gives a final drive ratio of 3.28. The 520 Oseries chain has been used over the 530 series, as it offers a better fit for our pitch and chain length. The sprocket was manufactured at the facility of LGB sports. Material used was Al 7075. Aluminum 7075 provides the advantage of reduced weight with high strength. Differential mountings were made of aluminum rested on the base of mild steel bolted to space frame. Mountings were in shape of two C cups bolted together to hold differential bearings. Design Calculations: The front sprocket of the HONDA CBR R600 engine used by our vehicle

is a 14-teeth Al 7075 sprocket. Target Speed (without restrictor) = 165 km/hr No. of teeth on small sprocket, z = 14.


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Diameter of smaller sprocket, d = p / Sin(180/z) = 15.875 / Sin(180/14) = 71.34mm For 40 teeth on driven sprocket, at 10000 rpm – 1st gear = 69.01 km/hr 2nd gear = 94.82 km/hr 3rd gear = 110.73 km/hr 4th gear = 137.61 km/hr 5th gear = 153.72 km/hr 6th gear = 166.7 km/hr Final gear ratio = 40/14 = 2.857 Now, velocity at wheels: V = [(pi) x D x N / 60000] m/s N at wheels = [10000 / (1.822 x 1.173 x 2.857)] = 1637.73 rpm Therefore, V = 166.701 km/hr Diameter of driven sprocket: D = p / Sin(180/Z) = 15.875 / Sin(180/40) = 202.33mm Pitch, p = 15.875mm = .625” = 5/8” Available motorcycle chains are 520, 525 and 530 series. Roller Dia = 5/8 of pitch = .390 = 0.4” (standard figure) Roller Width = Chain Width – 2 x Plate Thickness = (5/8 x .625) .62 5) – (2/8 x .625) = .25” . 25” = ¼” So, 520 series chain is selected. Corresponding sprocket thickness = .227” = 5.76mm Or, sprocket thickness = .93 x Roller Width - .006” = .226” ~ .227” (standard figure) Angle between teeth = 360/40 = 9 deg. Dia of bore = 3” = 76.2mm Half Shaft Analysis: Assumed Weight of car + driver = 400 kg.


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Assuming the worst case of 100% weight transfer to the rear wheels on launch, a coefficient of friction of 1.3, and a tire with a 270mm rolling radius, the maximum torque per axle would be, τmax = (400 x 1.3 x .270)/2 = 70.2 kg-m Using this torque, and the Handbook stress calculation for a tubular halfshaft, we can calculate the stress: Stress, σ = [16 x T] / [(pi)x(d^3)x(1-k^4)] = 503694675.6 N/m2 Assuming that shear ultimate is 75% of tension ultimate (again from the handbook) the ultimate shear stress for 300M steel would be (assuming heat treated to Rc54) would be about: 280,000 psi x .75 = 210,000 psi = 1448000000 N/m2 Therefore, the Margin of Safety in absolute worst case scenario, MOS = 1448000000 / 503694675.6 = 2.87 Communication with Taylor Race Engineering provided that actual failure upon testing only occurred at 1800 ft-lb = 248.2 248. 2 N-m. Therefore, in practical test situations, MOS = 248.2 / 70.2 = 3.54

TRE Differential with mountings


Halfshafts

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Suspension: The suspension was designed with the intention of keeping good straight line stability and minimal load transfer during cornering, braking and acceleration. The suspension is of Double Wishbone type with unequal, non‐ parallel parallel A arms. To maintain stability at high speeds without any handling problems, a longer wheelbase was decided upon. This, besides giving us reduced longitudinal load transfer and understeer, also gave us more space to pack the rest of the components. The track ‐width was measured in proportion with the wheelbase, giving us good lateral load transfer and corner entry. A front track of1400mm and a rear track of 1350mm were chosen. For the design of the suspension geometry Mitchell software was used and iterative methodology was adopted. Finally inboard suspension geometry was installed due to reduce unsprung mass and lesser aerodynamic drag. The suspension geometry gives us a rising rate, thus maintaining a consistent roll stiffness ratio throughout the suspension range and helping us to avoid bottoming of the dampers. The front roll centre was kept 15mm above the ground to keep the jacking forces and the roll moment arm minimal. The rear roll centre was kept higher, at 37mm, so as to reduce the roll moment arm even further. A minimal roll moment arm at the rear is important or stability in our case of a rear ‐mounted engine. Static camber of negative 1.5 degrees at the front and negative 2.5 degrees at the rear has been kept initially. Spring damper system was ordered from rise racing. Spring used had stiffness of 250 pounds per inch. Dampers were such that its damping coefficient can be varied with the help of valve. A arms were made of Mild Steel and TIG welding was done wherever required. Pipe used has elliptical cross section. Suspension mounting brackets were made of 2mm thick mild steel.

Front Steering Geometry


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Analysis on Mitchell Software


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Steering System:

Rack and pinion steering system was selected for our car. There are

advantages of choosing the rack and pinion steering gears over other types of steering systems. The rack and pinion steering gear is compact and it uses fewer parts. Therefore, it requires lesser space for installation. With a rack and pinion steering gear, the rack is connected by linkage directly to the upright. It does not require complicated linkage to change the rotary output of the steering shaft to back and forth movement of the wheels. Therefore, the rack and pinion steering gear system is relatively light. The simple steering linkage gives sharp steering response; hence the road feel is improved. Design constrains: The steering system must affect at least two wheels to operate effectively. The steering system must also have positive steering stops, which prevent the steering linkages from locking up. The stops may be placed on the uprights or on the rack and must prevent the tires from contacting suspension, body, or frame members during the track events. Allowable steering free pay will be limited to 7 degrees total, measured at the steering wheel. The steering system must not exhibit any bump steer characteristics. The steering wheel must round in shape and the top of the steering wheel must lower than the front hoop of the chassis. The steering wheel must be removable for quick driver exit of the car. Design specification: Since Formula SAE race cars are required to turn sharp corners, perfect Ackerman geometry is desired. In order to achieve perfect Ackerman, a straight line is constructed from the tie rod end to the kingpin axis, extended and then intersecting at the centre of the rear axle. Numerous iterations were carried out to obtain optimize steering geometry. Steering ratio of 12:1 is desired. Steering was design for maximum turning angle of 30deg and minimum turning radius of 2.89m was obtained. Final rack length was decided to be 415mm and tie rod length of 344mm. As per the above specification, a customized steering was manufactured at the manufacturing plant of RANE TRW Steering system limited. However during the fabrication of car, track width was increased and hence above steering system could not be used. Hence custom made aluminum rack machined at facility of LGB Sports was used. Later used rack was better than previous design as it was lighter compare to the previous design and required less effort for turning because of increased steering arm length. Because of the larger wheel base of the car, rack was placed in front of the driver foot. It pose a big problem as rack was hitting the master cylinder. Hence modification was done in master cylinder mounting plate to incorporate rack in that confined space.


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Rack and Pinion Final Steering Specifications: Number of turns lock to lock

2 turns

Rack travel per turn

41mm

Steering Arm length

60mm

Steering Arm angle with front Axial line

59deg

Rack length

415mm

Tie Rod length

344mm

Tie Rod Diameters

inner dia=15mm, outer dia=19mm

Rack position

60mm behind front tires centre line

Maximum turning angle

30deg

Minimum Turning Radius

2.89m

Steering Ratio

12:1


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Braking System: It was required to design a brake system for a vehicle of mass of approximately 300kg, maximum speeds of 120 km/hr and average speed of 60km/hr. The brake system must give high performance braking efficiency and stability during operation. The weight and the dimension of the brake system must be as small as possible because of the unsprung weight and inside wheel diameter limitation. Finally, the safety of the vehicle occupant is also a primary concern. Selection of braking system: A disc brake system is used in the front and rear of the car. The advantages of disc brake system are its stability to enable more consistent frictional behavior to be obtained from the front brake. It also has given a better braking performance at high speed to overcome fade associated with the high temperatures developed. On the thermal side, disc brake systems can lose heat very quickly because air can reach the discs every time the brakes are applied. During the running of the car, most of the load will be transferred to front of the car when braking. Thus, a stable brake system must design at the front of the ca r. Final design: It has been decided to use disc brakes of pulsar 150cc on all the four wheels having outer diameter of 240mm. Static weight distribution 0f 45:55 is considered. It is require, to have separate hydraulic circuits for front and rear for safety purpose. Hence, two master cylinders were used. II type hydraulic circuits will be used since our vehicle is rear heavy. Pulsar disc brakes were used because they were light, cheap and easily available. Better design would have been to use disc different size on rear and front wheels so better ratio can be obtained. But our options were limited in India. It was not possible to fit a disk bigger than 240mm in 13inch wheel and disk smaller than 240mm would have not produced enough brake torque. Twin piston floating calipers were used on all four wheels with bore diameter 20mm.Since actuating components on all four wheels were similar, proper brake ratio was obtained with the help of using separate master cylinder for rear and front, having different bore diameter. Front master cylinder has bore diameter 15.5mm and rear has 19.8 mm. Rear master cylinder was obtained from Maruti 800. However since 15.5mm bore master cylinder was not available in the market slave cylinder was used as master cylinder. Brake pedal custom made and has a pedal ratio of 4:1. Higher ratio was better but could not be obtained because of space constrained. Since hubs for our car were exported, a separate aluminum plate was fabricated for each wheel having six slots, on which disc was bolted. Aluminum was used as it has less weight and hence reduces the unsprung mass. Both flexible and rigid mild steel brake lines were used as per the requirement.


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Floating Caliper

Master Cylinder


Connector Flange

Brake Disc

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Upright Design:

Upright connects the suspension geometry and the wheels. Upright is provided with various mounting for steering, suspension arms, brake disc etc. Uprights should be light weight as they are part of unsprung u nsprung mass. We made the upright design on CATIA and validated it on ANSYS for various loads of static and fluctuating nature. The uprights were manufactured out of single blocks of 6082 grade Aluminum. Key suspension parameters can be easily adjusted during testing, since the mounts or A‐arms and brake calipers are fixed onto the upright. This process also decreases material cost and wastage.

ANSYS validation of Upright


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Engine: The engine chosen was based on the best power to weight ratio, availability and the restriction of using a maximum 610cc displacement engine for the FSAE competition. The Honda CBR 600F4i was best suited for the above needs and is the most powerful 600cc engine producing 103.5bhp for a weight of just 59kgs.The engine has a cassette built 6 speed wet multiplate clutch gearbox with a primary reduction of 1.822, and a final sprocket for output. This sprocket was linked to the final differential. The specifications of the engine are as follows: Inline 4 cylinder 4 stroke Compression ratio =12:1 Bore x Stroke=67 x 42.5 mm Fuel system: Injection. Programmed Fuel Injection (PGM-FI) with automatic enricher circuit Dual Overhead Camshafts Computer controlled transistorized with Coil-on-plug Ignition System Liquid Cooled

Engine mounted on Space Frame Department of Mechanical and Manufacturing Manufacturing

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The main objective was to mount the engine on the chassis and ensure its proper running, design of the intake manifold, manufacture of a new fuel tank, and fuel metering. Engine mounting and running: This was achieved by thorough understanding of the engine

manual and troubleshooting, and the engine electronics map. The fuel and ignition system diagrams were studied in detail and the sensors involved were carefully understood along with their relationship with each other as well as the ECU (Electronic Control Unit).For example the MAP (Manifold Absolute Pressure sensor) sensor was directly used for load measurement along with the IAT sensor. But if the IAT was not connected the ECU could extrapolate the load data from the MAP alone. Similarly the Bank angle sensor used as a safety measure in the original bike, was coupled with the ignition circuit and its function was to break the ignition circuit in case the vehicle toppled. The troubleshoot guide in the engine manual was used whenever the engine was not firing, to understand and overcome electronics problems for example the breaking of the main ignition fuse, any a ny fault with the pressure regulator, loss of battery voltage or a faulty spark plugs etc. Intake Restrictor Design: The Intake Restrictor is a component which is to be designed and

fabricated by the students for the FSAE competition. Except the diameter of the throat the rest parameters are flexible and can be designed according to our specific requirements. The basic design for the restrictor with all the parameters in terms of the throat diameter and the length of the restrictor is shown below.


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The throat diameter is fixed an its value is 20mm. F r the engine we were orking with we decided o choke it at 10,500 R PM to get he maximu mass flo rate through the restr ictor. This RP was arri ed at by using the basic equatio s used to alculate th mass flow rate through convergin -diverging ozzle.

= The Mach number i equal to 1 for choked low at the throat. Usin these we got the mass-flow rate as .7kg/s, which would be ideal for our purpos . After car rying out uch iterati n on FLUEN we arrived at the follo ing geometrical dimensions of the restrictor: The inlet diameter = 38mm The outl t diameter 60mm The tape half-angle at the diver ing section = 4.5 degrees The tape half-angle at the converging section = 3.5 deg ees The following are he results obtained b modelling the restrictor in the 3-dimensio s on GAMBI and analyzing it on LUENT. The k-epsilo model of turbulence as used f r the analysis and aroun 2000 iter tions were carried ou . The cha ge in the ensity of sir is according to the ideal gas equati n. The bou dary condi ions given ere: Pressure Inlet and P essure outl t with an a erage pres ure differe ce between them being 0.08 bars.

Department of Mech nical and M nufacturin

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It is clear that the air is accelerated at the throat. The magnitude of the static pressure starts increasing as it moves through the diverging section of the nozzle. Its maximum value is at the inlet and minimum at the throat. Design of the Intake Manifold: The Intake manifold was redesigned because of requirements of a

20mm restrictor at the upstream of the plenum, just after the air filter as per the competition rules. The aim was to keep a large plenum volume for good power surge at low RPMs. This was due to the relatively high weight of the car and requirement of good initial acceleration. The plenum volume was kept at 1960cc. The volume was decide depending on empirical equations from years of research from automotive firms, as is given in the following p aragraph. Tunnel Ram intake runners with bell mouth ends were chosen for easy manufacturing and their extensive use in race applications. The runner lengths were chosen for effective 3rd order reflections of the reflected wave from the bell be ll mouths, for 9000 RPM , which is on the lower side given that maximum engine RPM was close to 16000. This method of ram charging is effective in increasing power by about 15 to 20 percent. The lower RPM design was again for good low speed acceleration. Intake manifold design for 9000 rpm

Intake valve opens =22BTDC Intake valve closes=43ABDC Crank angles for which inlet valve is open=245 degrees Crank angles for which inlet valve is closed=475 degrees. Time for which inlet valve is closed=0.008796 closed=0.00 8796 second=EVCD(Effective valve closed duration) Let RV=6 Then 12 total reflections give 12L=0.008796 * 342.9 L=0.2513m=251.3mm Let RV=8 16L=0.008796 * 342.9 L=0.1885m=188.5mm By david vizerds formula L=17.8 + (1 * 4.3)=22.1cm=221mm Diameter of Intake Runners

SQRT(target rpm * displacement * percent volumetric vo lumetric efficiency)/3330) Department of Mechanical and Manufacturing Manufacturing

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=SQRT((9000 * 0.599 * 0.9)/3330)=1.20737 inch=30.6mm But due to the throttle body bore on the Honda cbr(stock) being 38mm we keep intake runner diameter as 38mm. Using formula in GRAPEAPE racing ,we get L= ((EVCD * 0.25 * V * 2)/(RPM * RV)) – (0.5 * diameter of runner inches) For RV=2,L=16.404inch=416.68mm For RV=3,L=10.687inch=271.45mm For RV=4,L=7.828inch=198.84mm For RV=5,L=6.1130inch=155.272mm For RV=6,L=4.96956inch=126.22mm For reflective value of RV=3,L=271.45mm is selected PLENUM VOLUME As per suggestions from 92TypeR racing We select plenum diameter=1.5 to 1.7 * (diameter of runner)=57mm to 64.6mm Taking plenum diameter as 58mm.This would ensure good initial acceleration According to Mr Leela Krishnan who is an Ex-national rally champion and a professional racer, we take plenum volume=1.5 * volume of a runner The volume of runner runner =3.14* {(40/1000)^2}/4 * 270/1000.=3.3929 * 10^-4 The plenum volume=1.5 * 3.3929*10^-4=5.08935 * 10^-4mm3 The length of the plenum to accommodate the runners is 310mmTherefore diameter of the plenum is= 45.7mm.We keep plenum diameter as 45mm.The CFM for maximum rpm of 10000 and 90 percent Volumetric efficiency comes out to be 95. RAM Tube Diameter

D in inches =SQRT ((Cubic inch displacement * volumetric efficiency * rpm)/(V * 1130)) V=speed of pressure wave =180ft/sec Designing this for 8000 rpm since 1000 rpm less than plenum rpm design. D in inches=SQRT((36.55 * 0.9 * 8000)/(180 * 1130))=1.1374inch=28.89mm But the Honda ram tubes fitted on the cylinder head with 38mm.Thus we have to keep the Runner diameter at 38mm The design of the restrictor nozzle was done by use of Fluent and basic Bernoulli’s treatment of nozzles. We obtained a shockwave in the calculations, just after the throat(20mm) throat(20mm) by which Mac number dropped from supersonic to subsonic suddenly and our aim was to make the exit Department of Mechanical and Manufacturing Manufacturing

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large enough for the air to reduce speed to about 223feet/sec i.e. around 0.75gms/sec. at the plenum. For this we obtain 70mm 7 0mm as the final exit diameter and we freeze the plenum diameter at 80mm.Thus the plenum would serve as a good storage of air. The restrictor design along with the final design of the manifold is given below.

The Maruti 800cc throttle body for inlet of air was selected based on advice from literature sources which specify that a large plenum of volume between 1200cc to 1800cc should have throttle body size ranging from 20mm to 40mm.The Maruti throttle body was easily available and was an average of the above reading. The Intake manifold was manufactured of Stainless Steel with sheet folding and TIG welding the lines. The Plenum was internally buffed to give as fine a finish as possible. The restrictor was also made with sheet metal. Due to lack of experienced hands the internal surfaces were not very well finished, with weld juts which had to be removed by grinding and buffing. Also smooth bend of the designed restrictor was not possible thus increasing friction head loss in flow. The restrictor analysis as was done is given below. The pressure at the plenum was approximated at 0.8 bar so that the design can produce minimum drop in pressure. Due to the throat restriction of 20mm the air speed at the throat reaches sonic speed and causes the drop in pressure. The nozzle design ensures recovery of the pressure as much as possible to 0.8 bar so that the plenum has full of air at this pressure for the engine to take in. Fuel Metering:

The metering and control of fuel injection was accomplished by making use of the DYNOJET POWER COMMANDER for the Honda CBR f4i . The power commander is essentially a piggyback ECU which is connected to the ECU through its fuel injection plug loom. This device alters the signal of the ECU to the injectors as per the map we feed into its memory. Department of Mechanical and Manufacturing Manufacturing

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The input map consists of the RPM on y axis and throttle opening percentage on the x axis. The values entered in the boxes are percentage decrease or increase of duty cycle of fuel injectors altered from basic ECU signal. Thus a negative sign indicates the duty cycle is reduced and thus lesser opening of the injector, supplying lesser fuel. The map is inputted into the device by computer USB and the fuel is controlled as per RPM and throttle opening. The fuel opening at lower rpms had to be made about -30 to -20(duty cycle percentage decrease) due to large pressure at the plenum to which the MAP was connected. Thus probably the ECU would sense the MAP reading as high air concentration, thus increasing fuel supply to maintain set A/F ratio. The idling was tuned for 8.5 percent Throttle opening. Due to lack of a dynamometer and lack of time we could not perform a dyno test of the engine for further optimization of the manifold and fuel metering control. The fuel metering performance was tuned with assistance from Mr Leela Krishnan due to his vast experience in race engine tuning. Further optimization is still possible with help of a dynamometer test.


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FINANCES of FM of FM-08 -08 The Cost Report of Formula Manipal 08 (Manipal University) is a financial analysis of the oneoff production of the FM 08 600cc race car. This report is intended for the perusal of a race-car production firm, with the objective of mass-production of this car, looking at the “weekend amateur racer” as its potential market. The FM 08 has been designed and manufactured for the FSAE Italy competition held during 20th – 22nd September, 2008. Since Formula Manipal was a first year team, several obstacles were faced during the design and manufacture of this first-year vehicle. Numerous changes made in design and purchase decisions over the passage of one and a half years, have had their impact on the Cost Report.Since the inception of the project, cost-friendliness has been a major design goal. Before any purchasing decision was made, we have made efforts to find lesser-cost alternatives offering similar performance and reliability. However, in the efforts to reduce cost, one must not discount on car performance and reliability. Due to shortage of racing-standard equipments in India, we have imported a significant number of car-parts from Europe and America. Cost-reducing measures must take a hit sometimes, if performance is to be guaranteed to the “weekend amateur racer”. This policy is reflected in our resolute decision to purchase the Taylor Race Engineering differential with pre-constructed housing, over slightly cheaper available substitutes. On the other hand, we have purchased parts indigenously whenever they were found to match desired performance, since they come at farlesser costs. In this respect, Bajaj Pulsar brake calipers and Rado wheels have been purchased over more popular conventionally preferred international products. The exchange rate for the US Dollar with respect to the Indian Rupee was $1 to Rs.39.40, to the Euro was $1 to € 0.6785, and to the Pound was $1 to £ 0.504 as on 2nd January 2008. This is the standard henceforth used to budget budg et the money spent within the $25,000 limit. The fabrication of FM-08 was possible by getting funding from various corporate. Following is the list of sponsors who were associated with FM-08:

Main Sponsors 1) Manipal University 2) Maruti Udyog Ltd 3) Manipal Universal Learning 4) National Instruments Ltd Associate Sponsors 1) Sparco 2) Bosch 3) L G Balakrishnan Balakrishnan and Bros.-engine, gear box and overall design evaluation 4) J K Tyres Department of Mechanical and Manufacturing Manufacturing

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Additio al sponsor 1) elphi TVS ltd 2) icardo 3) ane TRW Steering Systems Limite 4) ltair Engin ering 5) dsync - Ma keting Sup ort 6) TEBMA Shi yard In total e have ge erated Rs. .4 million in cash and Rs. 2.5 mil ion in-kind sponsorshi . All this wer done with dedication of all team members. Handling fi ances of t am helped team member to make budget and execution of plan. They learned many things like arketing, bill of material, planned an un-planne budget an cost break up.

Brake System Engin and Drivetrain Fram and body Instrumentation an Wirin Miscellaneous, Fit a d Finish Steering System Suspension and Shocks

Cost Sum st Sum ary of FM f FM 0 8 Area Tot ls Sub Total ($) ($)

B ake System

Labo Laborr fo Assembly to Vehicle ($)

397.87

Total ($)

192.5

590.37

E gine and Dri etrain

505 5053.25

490 490

5543.25

Frame and body

211 2113.68

437.5

2551.18

Instrumentation and Wiring

139 1393.66

262.5

1656.16

Miscellaneous, Fit and Finis

593.23

122.5

715.73

208.85

140 140

348.85

S spension an Shocks

121 1214.88

245 245

1459.88

Wheels, bearin gs and tires

195 1951.41

122.5

Steering Syste

Total Co t

Department of Mech nical and M nufacturin

2073.91

14939.33

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SUMMARY The successful participation in FSAE, Italy 2008, has marked the culmination of our project. We were extremely pleased with our performance. The FM 08, had met with all our expectations in terms of design and part operations. Having completed all end-level manufacture and some amount of track- testing at the Kari Motor Speedway in Coimbatore, India helped us give a strong representation at the FSAE Italy competition this year. In the process of the competition, we became the first Indian team in the current year to qualify for all the four dynamic events at the competition. Although we did successfully complete the task we started out on, we do believe there are several aspects of the car that need to be redesigned. Design being an iterative process, this would take several complete cycles of prototyping and testing, before we arrive at a world championship winning car. The major areas of design consideration would be weight reduction and packaging optimization. Also, at the end of it all the successful implementation of the Data Acquisition system would help us fine tune the car, and be ready for a much improved performance in the 2009 competition.


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Formula Manipal Report

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