ODU Formula SAE
MAE 435 - Spring 2013
Final Report
Faculty Advisors:
Dr. Sebastian Bawab
Dr. Collin Britcher
Dr. Nathan Luetke
Students:
Chris Caulkins
Andrew Rowe
Andrew Myers
Thomas Guglielmo
Aaron Hopkins
Stephen Christiansen
Charles Pearson
Kamod Gautam
Kevin Kelly
1
Abstract
The ODU Formula SAE team is well on its way to completing the 2013 vehicle.
Significant progress has been made in getting the team and vehicle ready for competition in
May. The main portions of the vehicle, such as frame, engine, suspension, and other hardware
are in place. In parallel with fabricating the new vehicle, the team has improved driving skills
using the 2012 vehicle. The combination of a well-designed vehicle and skilled drivers are
important for success in competition.
A large portion of the vehicle was designed by the previous semester’s team, and
approved by SAE early this year. After approval was given, the designs of the frame,
suspension, and control systems were constructed in the Motorsports Lab. In addition, other
critical components were added to the vehicle. Such tasks as creating a way to securely mount
the differential off of the rear of the frame were anecdote via a cantilevered bracket mounting
system. Conversely, the pedal layout was altered to allow for the addition of a clutch pedal, to
allow for a more intuitive driver experience. This pedal design was highly debated, and after
stringent computer analysis and redesigning, a final layout was constructed. In order to
maintain structural rigidity while decreasing the overall weight of the car several components
were machined out of aluminum, which include the front and rear rockers, the pedals, and the
front and rear uprights.
The engine mounting and positioning is particularly critical because of the large amount
of weight it adds. The engine mounting setup was designed in order to achieve the lowest
center of gravity as possible. A custom oil pan was fabricated which lowered the engine and
therefore created a low center of gravity. This greatly benefits the drivability and handling of
the vehicle. Engine performance testing was conducted using the 2012 vehicle because it
contains an identical engine. This provided a baseline which will be transferred to the new
vehicle that will require minimal changes due to different air intake setup.
Aero team's contributions are nearly complete as body panels, side-pods, and nose cone
are in assembly and paint process. The body panels were made from a light but stiff 4 layer
vacuum bagged fiberglass. The underbody tray required a stiffer construction so 10 layers of
fiberglass was used. The nose-cone, side-pods, and rear diffuser required additional support so
foam reinforcements were used between 8 layers of fiberglass. Minimal body work will be
required due to the use of female molds in the fabrication process. Aero team's other
responsibilities include fabrication of the seat, seat mounting, safety harness, and driver
ergonomics.
2
Table of Contents
Abstract ..........................................................................................................................................2
Table of Contents............................................................................................................................3
List of Figures..................................................................................................................................4
Introduction ...................................................................................................................................5
Background ....................................................................................................................................6
Methods.......................................................................................................................................12
1.1 Powertrain..................................................................................................................12
1.2 Aerodynamics.............................................................................................................16
1.3 Chassis........................................................................................................................20
1.4 Suspension/Brakes.....................................................................................................21
1.5 Controls......................................................................................................................22
Results..........................................................................................................................................24
2.1
Powertrain........................................................................................................................23
2.2
Aerodynamics...................................................................................................................24
Discussion.....................................................................................................................................27
Appendices...................................................................................................................................28
References....................................................................................................................................38
3
List of Figures
Figure 1: 2012 ODU Formula Car performing the Acceleration test..............................................8
Figure 2: Skid Pad Layout...............................................................................................................9
Figure 3: The 2012 ODU Formula Car Performing the Skidpad Test.............................................10
Figure 4: The 2012 ODU Formula Car Performing the Autocross Test.........................................11
Figure 5: Dyno curve for 2012 ODU FSAE vehicle........................................................................13
Figure 6: Baseline fuel map transferred from old ECU................................................................14
Figure 7: Two 7” fans produce maximum airflow through radiator............................................15
Figure 8: Fuel injector rail assembly............................................................................................16
Figure 9: Side-pod mold being vacuum bagged...........................................................................17
Figure 10: A near perfectly smooth panel due to the use of female molds................................18
Figure 11: A heat lamp was used to cure the resin overnight; the surface temperature was
maintained at 90 Deg while atmospheric temperature was close to 40 deg...............................19
Figure 12: Nose cone mold was split in two sections to allow the mold to be reuseable to aid
future formula teams...................................................................................................................19
Figure 13: Impact Attenuator.......................................................................................................20
Figure 14: Chassis.........................................................................................................................21
Figure 15: Steering Arm................................................................................................................23
Figure 16: Mounted Shocks and Spring........................................................................................23
Figure 17: Baseline compared to updated fuel map....................................................................24
Figure 18: Improved power output after tuning ECU...................................................................25
Figure 19: A smooth “showroom” finish is a byproduct of using female molds and vacuum
bagging technique........................................................................................................................25
Figure 20: Body panels fastened onto car...................................................................................26
4
Appendix
Figure A1: Project Gantt chart......................................................................................................28
Figure A.1a: FSAE Club Gantt chart...................................................................................29
Figure A.1b: Aerodynamics Team Gantt chart..................................................................30
Figure A.1c:Powertrain Team Gantt chart........................................................................31
Figure A.1d:Chassis Team Gantt chart..............................................................................32
Figure A2: Aero body budget.......................................................................................................33
Figure A3: Aero safety budget.....................................................................................................34
Figure A4: Aero team shop supplies budget................................................................................35
Figure A5: Powertrain Budget......................................................................................................36
Figure A6: Course Layout.............................................................................................................37
Introduction
The objective of Formula SAE team is to design, build, and drive a formula style car. The
goal for the spring team was to create a competitive car by expanding upon the designs and
goals of the Fall 2012 semester’s team. The group worked on building the different components
of the car with primary goal to get it ready for competition on May 2013. In order to complete
such a large task, the team was split into three groups, chassis, aerodynamics, and powertrain
which allowed for each component to be built and assembled simultaneously.
The objective of the chassis team was to design and built a high quality chassis including
its different vital components. The frame, suspension, brakes, controls and mounts for all
elements were built throughout the course of the semester. Similarly, the aerodynamics team
focused on designing and fabricating body panels, side-pods, nose cone and rear teardrop.
Their designated task was to make the car safe as well as aerodynamically efficient. Finally, the
powertrain team were responsible for designing and fabricating the fuel system for the car
along with fitting the engine into the car.
5
Background
Formula SAE is a race vehicle design competition for students attending universities
around the world. The first competition was held in 1978 and the longest running competition
is held annually in Michigan, which is where the Old Dominion Formula team will compete in
May 2013. The teams are run primarily by engineering students with some faculty guidance to
complete their projects. Each vehicle is designed and manufactured from the ground up and it
is each team’s responsibility to create a project plan in order stay under budget and produce a
final product for competition. The participating teams must produce a new vehicle for each
competition year.
There are currently 120 teams registered for the May 2013 Michigan competition that
ODU will compete against directly. The event is safety orientated, considering most team
members are amateurs, and the vehicles must pass several safety tests before being allowed to
compete. These include a rollover stability test, in which the tallest driver will sit in the vehicle
as it is tilted sixty degrees to determine if the vehicle has a tendency to rollover. There is also a
braking test in which the vehicle’s brakes will be tested by seeing if all four tires can be
simultaneously locked. Additionally, there is a noise test to determine if the vehicle is operating
at a safe noise level, 110 dB [1].
The competition has several judging aspects: design, performance, and endurance. The
design aspect consists of the judges giving scores for how well they believe the vehicle was
designed and built[1]. They will be taking everything into account, including cost and making
sure the team did not break any of the design rules.
There are two types of events, static and dynamic. The static events involve a design
and cost report that are given to the officials, who are experts from the automotive industry,
before the actual vehicle is tested. The design report explains the effort that went into the
vehicle and what engineering solutions were decided on to produce a functioning vehicle. The
cost report is a discussion on manufacturing the vehicle and it explains how much it would cost
to put the vehicle in large scale production. The presentation given to the officials will be based
off the design and cost reports. The goal is to prove to the officials that the team has a
comprehensive understanding of why the vehicle was decided in the way it was and how it can
be cost effective for large scale manufacturing.
The dynamic events include an acceleration test, skid pad test, autocross test, and
efficiency test. In these dynamic events, points will be awarded based on performance and
compared to the other teams in the competition (Tables 1 & 2)[1]. The endurance event is the
main event where the most possible points can be earned. The endurance event consists of a
twenty-two kilometer race to test the vehicles’ durability under long term conditions.
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Table 1
Page 109 from 2013 FSAE Rule Book [1]
Table 2
Page 139 from 2013 FSAE Rule Book [1]
The first event is a flat straight line test to evaluate the the car’s acceleration. This test
consists of two heats driven by two different drivers down a 75 m length of track. The score is
based off the fastest car and the total corrected time (elapsed time + penalty time). The
scoring equation can be found in section D5.8.2 of the FSAE Rule Book.
Acceleration Score = (71.5 x (Tmax/Tyour)-1)/((Tmax/Tmin)-1) + 3.5
Tyour = best corrected elapsed time including penalties
Tmin = elapsed time of fastest car
Tmax = 150% of Tmin
The scores range from a maximum of 75 to a minimum of 0 points for a Did Not Finish (DNF) in
the acceleration competition.
7
Knowing the baseline, the acceleration goal for the 2013 car can be accessed. The goal is to
have an acceleration of 6.5 m/s^2. This translates to a completion time of
Due to the weight reduction from last year’s car the goal is expected to be met.
Figure 1 2012 ODU Formula Car performing the Acceleration Test
The Skid-Pad event is designed to test the cars ability to turn in a constant radius. There are
two heats run by different drivers of which each heat consists of two laps. The layout of the
skid pad is below.
8
Figure 2 Skid Pad Layout
The skid pad scoring is computed by the judges using the following formula in section D6.8.3.
Skid Pad Score = (47.5 x (Tmax/Tyour)^2-1)/((Tmax/Tmin)^2-1)+2.5
Tyour = best corrected elapsed time including penalties
Tmin = elapsed time of fastest car
Tmax = 125% of Tmin
Completion of the course is within 125% of the fastest time is essential to score above the
minimum allotted score of 2.5 points.
9
Figure 3 The 2012 ODU Formula Car Performing the Skidpad Test
The third event in the competition is the autocross course which is a track setup for an
individual car to test its maneuverability and handling. The goal of the course is to combine the
features of acceleration, braking and cornering in order to evaluate the car as a whole without
the pressures of other drivers. The score for the heat will be taken from the best lap of the two
drivers during one of the two heats run. The scoring is judged from the following equation
found in D7.8.1 of the FSAE Rulebook.
Autocross Score = 142.5 x((Tmax/Tyour)-1)/((Tmax/Tmin)-1) +7.5
Tmin = lowest corrected elapsed time for any competitor
Tmax = 145% of Tmin
Tyour = lowest corrected elapsed time of either heat of the team being scored
The scores can range from 150 to 7.5 unless the car is considered a DNF which constitutes a
score of 0.
10
Figure 4 The 2012 ODU Formula Car Performing the Autocross Test
The final competition is the endurance and efficiency event. This event is a single heat of
approximately 14 miles designed to test the car’s durability. The endurance track is similar to
the track for the autocross as seen in Figure A.6. The course consists of straight aways,
constant turns, hairpin turns, slaloms, and miscellaneous turns. The endurance score will be
calculated using the following formula found in section D8.20.2 of the FSAE Rulebook.
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The efficiency is scored based off another equation that can be found in section D8.23.3 of the
FSAE Rulebook.
The combination of these two scores are judged from the same event and are the majority of
the points in the performance section of the competition.
Methods
1.1
Powertrain
The Powertrain team has the responsibility to design and fabricate the heart of the
vehicle. The engine selected for this year’s vehicle is a 2006 GSX-R 600cc motorcycle engine
and transmission. The fuel injected 600cc engine is expected and rated to produce 80
horsepower in the 2013 car (as noted later in the dyno testing this transmits to roughly 70
horsepower at the rear wheels). The engine has a 2.64 in X 1.67 in (67 mm X 42.5 mm) bore
with a compression ratio of 12.5:1. The engine’s power is transmitted to a final drive ratio of
3.52, which is then transmitted through the axles to the wheels. This engine/transmission
combination is used because of the reliability, availability, and usability of components that
have been designed from year to year. Since a 20mm diameter air intake restrictor is designed
per FSAE rules, using 93 octane gasoline is preferred to produce optimum power output. The
2012 vehicle has the exact same engine, and from this we will perform testing at TCC using a
SuperFlow dynamometer to capture baseline data which can be closely correlated to the 2013
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vehicle. This includes parameters such as power output, torque output, speed and fuel/ECU
mapping. Below is data taken using facilities at TCC using the 2012 vehicle:
Figure 5
Dynamometer curve for 2012 ODU FSAE vehicle
Figure 1 shows many errors found in the fuel map of the engine control unit (ECU) which have
been fixed since this test was performed. Between 5,000 and 7,000 RPM the performance is
very poor due to switching from having a rich Air/Fuel ratio and then becoming lean. Proper
engine performance requires a consistent A/F ratio to ensure efficiency and power output. The
ECU used is manufactured by Performance Electronics (West Chester, OH). The specific model
chosen is the PE3 since it is identical to the one used in the previous car. This allows a custom
fuel map to be programmed and modified as needed. A more in depth fuel map is shown
below:
Figure 6
Baseline fuel map transferred from old ECU
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Transmitting the output of the engine to the ground is another key factor of
performance. The final gear drive ratio is found using the following ratio of number of gear
teeth:
drive ratio = Ndiff /Neng = 53/15 = 3.533 [2]
(1)
This will give a significant amount of torque transfer to the rear wheels. This must be
transferred through a differential. A torsional differential is used to accomplish this while
maintaining good handling and drivability.
The six speed sequential gearbox allows less room to be taken in the cabin for the
shifter. It also helps the driver enter the correct gear, as there is only one dimension of
allowable movement. The transmission utilizes a slider clutch to stop the rear wheels from
losing traction due to excessive engine braking. This feature should help prevent unnecessary
wheel lock in dynamic event which require braking.
Another hurdle to overcome in the design phase is engine cooling. A properly designed
cooling system will allow the engine to run under heavy loads and not overheat. The objective
of this system is to maintain a constant optimum operating temperature in the engine.
Furthermore, the cooling system must be reliable and lightweight while mounted on our
vehicle’s frame. The calculations and design criteria were completed in a previous semester and
concluded that the Suzuki factory standard radiator should be used because it provided
sufficient cooling and would be readily available. The radiator was mounted using two fans
which allows maximum airflow because of the shape of the geometry (Figure 3). The fans are
manufactured by Perma-Cool and are designed to flow 2300 SCFM each.
Figure 7
14
Two 7” fans produce maximum airflow through radiator
The air intake manifold is another important factor in engine performance. This was
designed and validated in a previous semester and will not be included in this report. A throttle
position sensor (TPS) is used to measure the amount of air let into the engine. A manifold
absolute pressure (MAP) sensor is also used.
Since this is a sequential port injection style engine fuel injectors are used. A single
injector is used for each cylinder. The specific calibration and flow calculations were performed
by Synerject in Newport News, VA. The injectors used are manufactured by Continental
Automotive in Newport News, VA. They are Deka(R) VII short with standard tip length injectors
with a 26 degree cone spray and produce 2.79 g/s static flow at 350 kPa.
This will use a full circuit fuel system. The pump will supply fuel to the injectors be
means of a regulator. The regulator is downstream of the injectors to allow the fuel to flow
through them at the proper pressure. The system pressure will need to be fine tuned to allow
the proper amount of fuel to flow to the engine. The fuel injector rail is seen in figure 4. Note
that each injector will point toward each valve head in order to be as efficient as possible.
Figure 8
Fuel injector rail assembly
In order for the injectors to provide consistent fuel to the engine, a regulator and pump
must provide such an environment. The same in-line, external fuel pump as used in the
previous car is used since it is proven to be an acceptable solution. A similar fuel regulator is
used as in the previous car as well. This regulator is adjustable which has the advantage of fine
tuning the fuel flow through the injectors. This is crucial in finding optimal engine performance
since the injectors need to stay in the linear range of performance. A pressure damper is not
15
used to eliminate pressure pulsations in the fuel system because there is not time to test and
prove it to be beneficial.
The fuel tank is made of aluminum to reduce its weight. The tank has two baffles
located inside of the fuel storage compartment to provide less weight transfer in lateral
acceleration (corners). Location was a design hurdle because of the difficulty of keeping the
center of gravity low and in the center. Also, the exhaust runs towards the front and port side
of the car and care needed to be taken in placing the fuel tank to prevent overheating. The
tank’s final location was decided to be under the backrest of the seat, due to its inclination. This
placed it away from the exhaust, which also was given more insulation for safety, and directly
on top of the frame, providing the lowest possible center of gravity.
The axles are made of steel for durability and are identical to the previous year’s car.
Since an axle was not broken last year we know that this is an acceptable design. The axles
connect to the wheel hubs through constant-velocity joints which allow the the drive shaft to
transmit power to the wheels under any loading condition in the range allowed by the
suspension.
The exhaust system is a combination of previous designs proven to produce acceptable
results. The headers are a 4-1 design with effective runner lengths of 12” each. They come
together into a small plenum which then runs to the muffler. The muffler is taken from a
similar size and style Yamaha engine. It was used and taken to a car in a previous competition,
so it is proven to satisfy the noise restriction requirement of 110 dB. This measurement is
taken 50cm away from the exit of the muffler at a 45 degree angle [1].
1.2
Aerodynamics
The aerodynamics team has been tasked the responsibility of designing and fabricating
the body panels, side-pods, nose cone, and rear teardrop. The aero team has also been tasked
with safety design and fabrication. Flat body panels were created using an advanced vacuum
bagging technique as opposed to a traditional hand lay fiber glassing technique.
A traditional method to laying fiberglass has several different ways for human error to
affect the outcome of the piece. Environmental factors such as dust or moisture could create
flaws in the fiberglass which could lead to issues later on in the fabrication. Laying the glass by
hand could also lead to the glass having issues with varying thicknesses or air bubbles inside the
finished product. The benefits from vacuum bagging outweigh the negatives that are
associated with the time and preparation it takes to set up the fabrication.
16
Figure 9
Side-pod mold being vacuum bagged
The vacuum bagging technique eliminates many of the issues that can be found in the
more traditional methods. Since the parts being fabricated for the vehicle are all relatively
small, this makes it ideal for the use of vacuum bagging. What vacuum bagging does is remove
the air from a mold and allow the epoxy to be distributed evenly between the mold and the
vacuum bag. This also creates a relatively smooth surface on both sides of the body panels that
normally would be tougher to achieve if laid by hand.
Figure 10
A near perfectly smooth panel due to the use of female molds
Vacuum bagging is a fairly simple process that can be done quickly and efficiently. The
first step is to set up the mold and vacuum bag it so that there is a smooth surface to begin
laying the glass. For a flat body panel, a 24” X 48” acrylic sheet was used to create not only a
nonstick surface but also a perfectly flat surface for the glass to mold to. After the mold has
been prepared a release agent cloth can be placed across the mold followed by the desired
layers of glass and then finally topped off with bleeder cloth across the entire mold. Once all of
the layers have been put down, the mold can be outlined using butyl tape. After the tape has
been laid out a tube with a spiral cut pattern can be draped across one end of the breather tape
17
so that the epoxy can be distributed across the glass. A second tube with the spiral cut pattern
will be covered in shop towels and placed across the other end of the mold. From here the
vacuum bag can be placed and secured over the mold and checked to see how well the seal is
holding. Once the seal has been properly tested the epoxy can be mixed and drawn through
the tube without the shop towels so that it covers the entirety of the glass. The tubes can then
be clamped and the whole mold placed under a heat lamp so that the epoxy can dry. Twenty
four hours later, heated by the heat lamp, the epoxy has cured enough for the mold to be
delaminated and the fiberglass to be removed from the vacuum bag.
Figure 11
A heat lamp was used to cure the resin overnight; the surface temperature was maintained at
90 Deg while atmospheric temperature was close to 40 Deg
The curved body panels required a slightly different method. Molds had to be custom
made before the vacuum bagging technique could be applied. These molds were made with
expanding foam and plywood. Plywood pieces were cut out and assembled into a skeleton of
the desired shape of the mold, and then expanding foam was used to cover the plywood
structure. The foam was then cut and rasped until it was flush with the plywood, and then
sanded until the desired shape was formed. After the shape is finalized, resin is poured over the
mold to fill in the pores of the foam, and it is sanded once more to give a smooth surface for
the vacuum molding process.
18
Figure 12
Nose cone mold was split in two sections to allow the mold to be reuseable to aid future formula
teams
The safety components that the aero team has been given responsibility of are the seat,
harnesses, and roll bar padding. The seat was custom made for a previous competition and fits
securely into this years car. It will be mounted at about a 37 degree angle which according to
page 50 sections T5.1 of the FSAE rulebook [1] is considered a reclined position and requires a
six point harness which has also been purchased online from Jegs (Columbus, OH). The
rulebook also states on page 53-54 section T5.6-5.7 that padding must be placed anywhere on
the frame where the driver’s helmet may come in contact with it so 0.5” roll bar padding and
padding for a head restraint have been purchased from Jegs.
The attenuator was purchased through Formula Society of Automotive Engineers as the
standard attenuator for the 2013 competition year. The schematic in figure 8 is of the 2012
version of the standard attenuator because it has been unchanged for the 2013 year. The
purpose of the attenuator is to safely decelerate the vehicle in the event of a frontal collision.
The frontal impact will compress the attenuator foam and create a relatively uniform force on
the anti-intrusion plate, which mounted to the attenuator and the frame on their respective
sides. The required load for the attenuator anti-intrusion plate is 26,755 pounds force and since
the FSAE setup was used no testing was required.
19
Figure 13 Impact Attenuator
1.3
Chassis
The chassis is an integral part of race vehicle performance. It consists of the frame,
suspension, brakes, controls, and mounting of all elements. The frame is the rigid body that all
parts of the vehicle are attached to. It is made out of one inch diameter Chromoly steel tubing
and welded together for strength and rigidity. The frame for the current vehicle will provide a
longer wheelbase and was designed without a rear box. This requires the rear differential to be
mounted cantilevered from the back of the frame. All of the mounting tabs were laser cut by
Bauer to ensure quality, consistency and integrity. A variety of tab shapes were made to allow
for flexibility when mounting different elements to the frame. Steel tabs were made as well as
aluminum tabs to mount certain elements. The entire frame and attached mounting tabs will
be painted matte black while the control arms and pushrods are painted silver metallic. The
total weight of the car without the driver is estimated to be just under 500 lbs.
20
Figure 14
Chassis
1.4
Suspension/Brakes
The suspension is a double wishbone type in the front and rear with adjustable caster,
camber, and toe. The rear suspension features coil over Penske shocks mounted directly to the
frame. The rear rockers are made in house from aluminum. The rear uprights are being reused,
and re-tooled to save time and money, also custom rear support arms have been made. Antipenetration bars have been made and installed on all suspension A-arms to increase the safety
of the driver in the event of a crash. All A-arms have been painted, properly spaced, and
attached to the car. The front suspension features coil over shocks and custom made rockers
that are all contained outside the frame to comply with competition rules. The motion ratio is
1:1 for the front suspension and 1:1.25 for the rear. The front uprights and spindles were
designed in house and the designs were sent to L&W to be machined. L&W has completed and
returned all parts needed for the suspension. The Wilwood hubs, brake calipers, master
cylinders, pads, and other small brake components were ordered through Jegs. The brake
rotors were designed in house and were laser cut by Bauer. The aforementioned calipers,
master cylinders, rotors, and pads are all completely mounted on the vehicle. There is one
brake caliper and rotor for each front wheel, and one brake caliper and rotor for the rear
wheels. The rear brake rotor is mounted directly to the rotating portion of the differential,
which only necessitates one rear brake caliper. The only remaining task for the brake system is
to complete the brake plumbing and cables. The wheels have a 13 inch diameter with slick
Hoosier tires and custom student-designed wheel centers. The only component of the
suspension that is incomplete is the wheel centers which are still being fabricated in the ODU
machine shop. The only elements of the chassis that are incomplete are the painting of the frame, the
brake plumbing and linkage, and the wheel centers. The steering system for the vehicle has been
21
completed and installed. Custom tie rods were made with heim joints to allow for dynamic toe of the
car. Clevis rod ends were machined in house from solid aluminum to connect the tie rods to the steering
rack.
1.5
Controls
The control pedals are being fabricated in the motorsports lab. In order to create a
more familiar driving atmosphere and also to free up the driver’s hands, the pedal design will
include a clutch pedal alongside the enlarged brake pedal and slim throttle. The base that the
pedals will be sitting on is to be made out of square tubing. The final design of this component
is still being created in SolidWorks (Dassault Systèmes SolidWorks Corp., Waltham, MA). The
rack and pinion assembly is being reused from a previous year. A bracket has been made and
the assembly is mounted to the frame. Tubing was cut and fitted to universal joints to make the
steering linkage. A housing was made to fit the bearings and steering column which was rigidly
connects them to the frame. The internal and external bearing sizes have been determined and
the bearings are to be ordered. A quick release steering wheel will be used on the vehicle to
allow quick driver change. A special hexagonal connector has been mounted to the end of the
steering column. The steering wheel can then be quickly and easily removed, in compliance
with page 49 section T4.8 of the 2013 FSAE Rule Book.
Figure 15
Steering Arm
22
Figure 16
Mounted Shocks and Spring.
Results
2.1
Powertrain
Engine tuning has proved to be a successful venture to the team. Using the previous
year’s vehicle at Tidewater Community College testing facility (Chesapeake, VA), the ECU
control and fuel map was tuned to remove fat and lean performance by using PE Monitor V.
This program allows the fuel map to be tuned and modified according to the specific
application. A 13 x 13 size fuel map of throttle position sensor vs revolutions per minute (TPS
vs RPM) is used since this is a common practice and both parameters are easily measured.
Below is a comparison between the baseline and updated fuel map tuning:
23
Figure 17
Baseline compared to updated fuel map
From the above graphs there was clearly a major change needed to optimize engine
performance. Once this was applied to the ECU and the proper fuel pressure was found,
performance increased greatly. Figure 10 shows the improved performance. This updated data
and tuning will be transferred to the new vehicle. Small changes are expected to be required
since the air intake and exhaust headers are different. However, even with small changes this
test showed great improvements that will directly apply to the new engine.
Figure 18
Improved power output after tuning ECU
2.2
Aerodynamics
Basic flat panel fiber glassing has proved to be an effective method of producing high
quality body panels. Simple 2 dimensional panels are easy to manufacture and are highly cost
effective. These panels are more than ½ the weight of an equally sized aluminum panel. Since
these panels are fabricated with a female mold there is little bodywork to be done. This saves
24
time as only a coat of paint and simple fasteners is all that remains to get the body panels on
the vehicle.
Figure 19
A smooth “showroom” finish is a byproduct of using female molds and vacuum bagging
technique
Initial measurements of body panels indicate that just over 60% total weight reduction
in the side body panels over last year's foam core design. This equates to 3 pounds saved for
every new panel that is installed. The nose cone resulted in a 70% weight reduction over last
years design as well as 10% reduction in drag coefficient. This reduction in mass and weight will
allow the car to accelerate and decelerate faster. This has resulted in approx 9 pound reduction
of weight in the front end of the car. The side pods will add about 6 pounds to the car that last
year did not have but the side pods allow more airflow over the components located in them.
This year the side pods will include the the cooling system in the left side and the exhaust
system in the right side. This allows this weight to be lowered and more centered over last
years design resulting in a lower and more centered C.G. A race car that has a lower, centered
C.G. will allow for better handling characteristics.
Figure 20
Body panels fastened onto car
25
2.3
Chassis
SolidWorks modeling was required to ensure the safety and proper function of
components that needed to be designed. Detailed measurements were taken from all of the
parts to be modeled, and these dimensions were entered into SolidWorks. After the parts were
modeled in 3 dimensions, constraints and forces had to be added in order to run a simulation.
Using the SolidWorks built in FEA simulation, the models were evaluated to ensure an
appropriate factor of safety appropriate factor of safety.
Figure 21
Stress Analysis of the impact attenuator
Figure 22
Stress Analysis of the brake pedal mount
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Figure 23
Stress Analysis of the brake pedal
Discussion
The ODU Formula SAE team has made significant progress in completing the vehicle in
order to compete in May 2013. The design phase has been completed and the final assembly
and fabrication has begun. This allows the students to apply engineering design skills alongside
hands-on manufacturing experience in a real world situation. This vehicle is then taken to a
worldwide competition between 120 engineering schools where the teams are scored based on
engineering designs and efficiency.
Engine performance tuning has shown important preliminary results that will greatly
benefit the knowledge and experience of the team, and will directly affect the new vehicle. A
vast majority of the engine tuning is complete since the engines are identical between this year
and the previous year vehicle.
The initial runs of the fiber glassing have returned good results. Flat body panels need
only a coat of paint and quick release fasteners are required. Three dimensional molds are
proving to be time consuming and difficult. The plus side of preparing three dimensional molds
is that the finished side is smooth and ready for a coat of paint. The use of multi-piece molds
will allow the molds to be reuseable. This will save future formula teams valuable time that
could be going to designing wings or other aero treatments. Once the seat arrives from Jegs
seat mounting and safety harness will be mocked up and mounted. Driver ergonomics are
going to be taking into account as soon as the seat is in place as reduction of driver fatigue is
important in the endurance race.
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Appendices
A1
Gantt chart
Figure A.1
Project Gantt chart
28
Figure A.1a
FSAE Club Gantt chart
29
Figure A.1b
Aerodynamics Team Gantt chart
30
Figure A.1c
Powertrain Team Gantt chart
31
Figure A.1d
Chassis Team Gantt chart
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Figure A.2
Aero body budget
33
Figure A.3
Aero safety budget
34
Figure A.4
Aero team shop supplies budget
35
Figure A.5
Powertrain Budget
36
Figure A.6
Course Layout
37
References
[1]
2013 Formula SAE Rules, 2013.
[2]
R. N. Budynas, Keith, Shigley's Mechanical Engineering Design (9th), 9th ed., 2011.
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