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Module 4
Fundamentals of Motorsport Technology
Contents:
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Pages: 2 – 6 Task 1 Alternator Bracket Design and FEA testing.
Pages: 7 – 10 Task 2 Gantt chart report.
Pages: 11 – 13 Task 3 Rally car logic circuit.
Pages: 14 – 20 Task 4 ECU control systems, sensors, and actuators.
Pages: 21 – 24 Task 5 Waveforms.
Page: 25 – References.
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Module 4
Task 1
Alternator Bracket design and FEA testing
Introduction
Three materials were tested for use on an alternator bracket under engine environmental conditions
with a max torque of 245N. This load was applied vertically onto the bracket.
Mg Alloy WE54-T6
Mg WE54-T6 is a lightweight, heat treatable alloy and has been used in applications including
Motorsport and aerospace. It is ideal for motorsport applications according to (Matmatch.com
(n.d.), due to “their light weight, high strength-to-weight ratio, high stiffness-to-weight ratio,
castability, machinability, and great damping.”
The use of magnesium alloys in the automotive and motorsport industry is also stated by (IMA
International Magnesium Association (n.d.). Its longevity of service life is another key advantage to
other alloys and according to (SmithsmetalcentresLtd (n.d.) “ The machinability of WE54 is excellent,
and the alloy provides similar corrosion resistance to aluminium casting alloys under salt spray
conditions”. This allows the user to be confident that it can be used on components in an engine
compartment or on lower mounted components without risk of corrosion issues.
Material characteristics that make this good for motorsport are its strength, low weight and good
levels of stiffness. According to (S.Ugendera, A.Kumar, A. Somi Reddy (2014)) “The Mg alloys are
especially attractive due to their low density, high specific stiffness and strength and also the
recycling ability”, showing that Magnesium alloys are a good choice of material for applications in
the motorsport industry.
The weight of the bracket is 29.091g. Of all three materials, Mg WE54-T6 is 2nd for weight and
considerably less then Ti6Al4V, the trade-off for this is a lower stress yield under the loads it was
tested with.
Figure 1: A max displacement of 1.783mm where the loads would directly apply.
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The worst affected areas, by displacement, are around the M10 hole in which the loads would be
vertically applied. The displacement could lead to potential damage and movement of both the
bracket and the alternator. Below is the image from the Von misses stress which shows the worst
affected area to be around a secondary bolt hole, used for packaging reasons and weight saving. The
max being 169.3 Mpa which is under the yield strength of the material itself.
Figure 2: The Key areas of Von Misses stress.
An improvement could be made by removing the M10 bolt hole, thus gaining strength but also
weight. However, the overall curve on the design and height would lead to extra stress in this area.
The trade-off for weight saving has been a positive design feature with all factors considered. The
safety factor achieved was 1.36. This is just above the industry design standard of 1.2 - 1.5, however,
when looking further into the results the minimum of 1.36 is reached in a very small, concentrated
area around the secondary bolt hole. This again shows that the design would likely pass using this
material under further design changes.
Figure 3: The safety factor diagram on the bracket.
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Ti-6Al-4V
Grade 5 Ti6Al4V is a fantastic material regarding its strength and corrosion resistance. Engine
components are prone to suffering from damage from corrosion which will often accelerate failures,
due to water ingress into the compartment.
Its use in marine and offshore gas and oil environments means that it is not only corrosion resistant
but also very strong, of all three materials tested, Ti6AI4V has the highest Tensile and yield strength.
The counter to this is its density and weight being very high in comparison. The titanium alloy
Ti6Al4V is the most dense and heaviest of all 3 chosen materials, with the bracket weight at 69.66g.
The displacement results showed a value of 0.72mm which is a vast improvement on the
displacement results of WE54-T6.
Figure 4: The displacement maximum on the Ti-6Al-4V bracket.
As seen from the above image the displacement again takes place in the expected area of the
alternator bolt hole. Interestingly, Ti6Al4V and WE54-T6 have a very close maximum von misses
stress. With WE54-T6 having a maximum of 169.3 Mpa, and Ti6Al4V reaching 169.2 Mpa, this
indicates that despite the extra density and increased strength the trade-off in the results for Stress,
mean that this material is not weight to strength efficient. This is likely because the forming of the
material is designed for larger structural components.
Figure 5: Indicates the Von Misses stress.
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The safety factor of 4.89, is a reinforcement of that point and would make this material, unsuitable
for this specific use and task. Combined with the high weight and slightly more difficult forming
processes, this material should not be used for this component.
AlBeMet®162 (AM162)
AM162 is an Aluminum-beryllium metal matrix composite, used in a huge range of industries
including Aerospace, Satellites, Automotive and more. In its initial development it could be found in
many military applications such as night and thermal vision optics and fire control systems, thus
demonstrating its trust in components that will be used in particularly harsh and brutal
environments.
The bracket using AM162 weighed 32.55 G, slightly more than WE54-T6 and considerably less than
Ti6Al4V. Due to its use of Beryllium and the advantages of such when formed with its aluminium
content means that weight and density are reduced without losing a large amount of its strength
properties.
A key selling point of AM162, that makes it ideal for use in the engine bay, is its high heat capacity.
Its displacement under test conditions resulted in a maximum of only 0.4078mm beating the other
two materials by a large margin.
Figure 6: With a max displacement of 0.4078mm AM162 has the best results.
This is in large part down to its high modulus ratio which is cited by (Materion (n.d) in their technical
fact sheet; “High modulus-to-density ratio, 4 times that of aluminum or steel, minimizes flexure and
reduces the chance of mechanically induced failure.” This should be a key consideration, as at max
torque an engine will induce other affects such as high volumes of vibration, which could severely
affect the bracket.
With a safety factor of 1.61 it falls just above the 1.5 guideline, meaning that it will not be an
overengineered product, and material, but also sits comfortably in safety factor considerations. As
an average consideration, below are the test results from Nixon Motorsports F1000 car in a recent
test.
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The test results were sent in YouTube comment section on the 12th of August 2021 by Nixon
Motorsport YouTube channel. “With outside air ambient temp 102F - Out lap 67.222°C, lap1 80°C,
lap2 82.222°C, lap3 82.222°C, lap4 81.667°C, lap5 83.333°C, lap6 83.889°C, lap7 83.889°C, in lap
82.222°C - overall average was 75.556°C.” (These results were converted to degrees Celsius; the
temperatures are the peak temperatures from any point during that lap and the average
temperature is taken from start to finish of the session).
The component will need to remain stable throughout this temperature range and should be
expected to have a considerably bigger threshold if it is to be deemed viable for use in an engine
compartment. AM162 has the ability on paper to comfortably withstand these levels of heat whilst
working under stress, although testing would need to be conducted to confirm the extent of its
capability.
Conclusion
According to the tests, AM162 is the ideal choice for use on the alternator bracket, its weight is very
low, and although only just heavier then WE54-T6 its mechanical and thermal properties beat it by a
large margin, its safety factor is much higher. All the materials had good corrosion resistance with
very little difference between the three. The main separator being the elasticity modulus, due to
AM162 having a unique advantage in that regard the displacement results swung in its favour,
ultimately leading to it being a safe, light and very strong material with the ability to perform under
stressful conditions for some time.
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Module 4
Task 2
Gannt Chart report
Totals
Engine 1 cost: £56,000 (X2 Rebuilds).
Gearbox 1 cost: £18,000 (X1 Rebuild).
Front Crossmember cost: £4,200 (X1 Purchase).
Total Cost: £134,200.
Total usage
Engine 1: 23 hours run before first rebuild. 28 Hours run before second rebuild (Le mans Qualy and
Race) 51 Hours run all season.
Engine 2: 17 hours run all season.
Gearbox 1: 34 Hours run before first rebuild. 28 after the rebuild. Total 62 hours run all season.
Gearbox 2: 28 Hours run all season
Front crossmember 1: 68 Hours run all season
Front crossmember 2: 22 Hours run all season
Introduction
This document and corresponding Gantt chart have planned a full race seasons component usage
and costing. The aim of the planning cycle is to balance both performance considerations and the
overall costs, keeping the economic restraints as low as reasonably possible as well as considering
time and work scale factors regarding the workload required.
Performance vs cost
This plan keeps an economic approach whilst maintaining an acceptable performance factor for all
components where possible. This has been done by using one component for as long as possible,
without dropping below a certain service life.
This strategy takes into consideration key events in the calendar which require two of the same
components to be used. Le mans is the longest event of the calendar and due to the length of
qualifying and the race requires one engine with a full-service life to give enough performance
throughout the race, meaning another engine needs to be used in practice, again with enough
performance to conduct the practice session.
The lowest life left in a component, that was then subsequently used was: Engine 1 down to 2 hours
run time. The engine was used in the qualifying and race of the Le Mans 24 hours, and was rebuilt
before the event, the second lowest service life in a component was also Engine 1 after being used in
preseason testing and the full event at Sebring leaving it with 7 hours run time.
Alternative commitments
Motorsport teams often have a high workload over limited time. The busiest days are race
weekends, however there are other commitments such as tyre manufacturer testing, sponsorship
events etc. These events don’t necessarily require components to be peak performance they may
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require working components on the car. This has been considered by ensuring there is always one of
each component with at least 6-7 hours remaining service life at any one time.
Many of the components will be used up to a certain service life and then not used on the car again.
This allows for any R and D to be conducted on these components, ready for future seasons. It also
means that there are components ready for emergency use at events, should any of the components
being used, require switching out.
Timing of planned servicing
The lead time of two weeks for rebuilds, of Engines and Gearboxes makes certain gaps between race
weekends unviable. With the events this season there is plenty of time to get these completed, with
space before and after. This is important as the team needs time to get back from events, conduct
post-race tasks and send off components for their rebuilds. Post-race tasks can include Magnetic
Particle Inspection (MPI), Dyno runs and shakedowns. Even in one of the leading motorsport teams
in the world, the process of conducting post-race component testing, is very time consuming, as
according to MercedesAMGF1.com/news (2018) “It's all in the details. Even the slightest defect can
potentially cause a race-ending failure, making the NDT department one of the most crucial (and
busiest!) parts of the team, working relentlessly to make sure every part on the car is fit for
purpose.”
After the
component returns, there is enough time to conduct any setup changes for upcoming events, such
as gear ratio changes. Consideration must be taken for this time when looking at the workforce
behind a race team. Often in smaller race teams employees will be conducting multiple tasks. It
would be incorrect to forget this factor and look simply at the number of days between each event,
if the workforce is overworked it can lead to fatigue and complacency two factors not associated
with motorsport success.
Due to the
economical approach to this race season, the number of rebuilds are, two for Engine 1 and one for
Gearbox 1.
Negatives
One problem is that, due to economic reasons, certain components will use up a lot of their service
life. Aside from the unavoidable Le Mans race, which requires at least 28 Hours run time due to parc
ferme, the lowest any components reached beside this event was 6 hours. (Two other components
reaching 7 hours). Although not ideal, the trade off in performance drop for economic gain is a
hugely positive one. During the season this will require the engineers to place more effort into
provision plans in case of a component failure and will also require much greater work in preparing a
good method for strategy to compensate for the reduce risk in performance drop in key
components. Due to the need to utilise extra components to keep this performance window, the Le
mans race week will be a busy one for the team as after Practice, both the gearbox and Engine will
need to be changed before the Qualifying session begins.
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Gannt Chart
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Race season output chart
Figure 7: The full season output chart for all components.
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Module 4
Task 3
Rally car logic circuit
Operation
The logic circuit was made using logic.ly. It’s function allows the driver to operate three different
switches for these three pre-sets: Service, Gravel and Tarmac.
Service: Traction Control on and Suspension settings off.
Gravel: Traction Control off and high Suspension setting on.
Tarmac: Traction Control off and low Suspension setting on.
Each input switch has a corresponding light that will indicate which setting is selected. Each setting
has been prioritised, with Service being the lowest, Gravel in the middle and Tarmac being the
highest. This means that if more than one switch is turned on, despite all the relevant bulbs being
illuminated, the priority setting shall be turned on. As seen below:
Figures 8, 9 and 10: Service setting is on however once gravel is switched on that setting becomes active, if all three are on
the Tarmac setting becomes active.
Also, by using two AND gates, none of the setting functions can be true at the same time. This is
because problems will likely occur with systems on the car if two or more settings were true at the
same time, e.g., both high and low suspension settings at the same time if the Gravel and Tarmac
settings were on.
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Service function
Service has one input switch; this leads to an indication bulb. Also, directly from the input switch it
leads to an AND gate which has three inputs. Through this AND gate it then leads onto the Traction
control function. The other switches also lead to this AND gate, the purpose of which is to allow the
changing of the settings in a much easier manor, if required later.
Gravel function
The gravel setting has one input switch, leading to an indication bulb. It then leads up to the first
AND gate via a NOT gate. This is to allow for a connection to be established with the traction control
function, without being live, meaning that when the gravel input is true, the TC output will not also
be true. From the input there is also a connection to a second AND gate, this one having only two
inputs. Leading out from this AND gate into the high suspension setting pre-set function. This means
that with both Gravel and Tarmac inputs into the second AND gate, only one can activate the gate.
Tarmac function
This input also leads to the second AND gate, however before it reaches there it passes through a
NOT gate, meaning that the Tarmac input, when True, will not activate the Low suspension pre-set
when activated. However it still enables a connection so any changes made later, if required, are
easier. The tarmac input also leads to the first AND gate, once again, passing through another NOT
gate, ensuring it cannot activate the TC on function when the input is true. Alongside this there are
two direct connections from the input switch, one being the indication bulb and the second being
the low suspension pre-set.
Truth Table
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Alternative Options
A good alternative to the options above would be to use a joystick style switch which would allow
the driver to navigate through the settings, either vertically or horizontally, in conjunction with a
digital display naming each setting. This would be beneficial as there would be more space on the
steering wheel itself, alternatively a rotary wheel could also be used.
The downside to these would be that they are easy to knock when driving and could change mid
stage. To counter this, for both options including each switch, would be to ensure the buttons have a
built-in guard around the switch so they can only be applied by deliberate action of the driver.
Figure 11: A Fanatec sim racing wheel with button switch and guard cover.
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Module 4
Task 4
ECU control systems, sensors, and actuators
Sensors
Crankshaft and Camshaft position sensors
Due to the engine running a turbocharger, with lambda and knock control as well as an ECU using
fuel, boost, lambda and ignition maps, it is vital that the engine runs both camshaft and crankshaft
position sensors.
The crankshaft sensor determines rotational speed, position of the crankshaft and pistons. It detects
the teeth mounted on the reluctor ring and the gap left in the teeth to indicate the position. The
rotation of the crankshaft is essential to the engine being powered. It is important the ECU has an
accurate and timely feedback of this data. The engine could cut out as the ECU times any injection
and ignition from this data.
The camshaft sensor relays, to the ECU, the position of the engine within its cycle to determine the
sequence of firing. Different types of sensors have different outputs, whilst the input remains
roughly the same, around 5v up to 24v depending on the type of sensor.
Figure 12: Hall sensor output voltages in waveform (Full function engineering 2012).
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Figure 13: Variable reluctance sensor output voltage in waveform. Note the blue alternating current (Full function
engineering 2012).
Manifold Absolute Pressure (MAP) sensor
A MAP sensor detects the intake manifold pressure, and subsequently calculates air volume. This
data is sent to the ECU, which will use it to adapt the fuel and ignition maps. The output to the ECU
will vary in voltage, depending on this reading, whereas the input will be 5v like other sensors.
Figure 14: The map sensor operation showing warping on the silicone diaphragm and the MAP circuit (A,Sohane n.d.).
Figure 15: MAP sensor signal voltage graph for a VAG 3Bar MAP sensor (Darkside Developments 2018).
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Throttle position sensor
A throttle position sensor is fitted, as the ECU utilises Throttle position vs RPM as the X and Y axis
across all maps. This monitors the position of the throttle valve and, particularly a motorsport spec
model, will usually have at least some input regardless of the throttle position being closed.
They tend to be a potentiometer using a sliding or rotating contact that acts as a divider, with two or
three terminal resistors. By only using two of the resistors, it becomes a variable resistor, the three
pin sensors inside include a 5v input.
By providing a variable output signal to the ECU it can determine any changes required to Maps such
as fuel injection timing, amongst others. Generally, the voltage input for a throttle position sensor is,
according to (Pico Technology n.d.) “in the region of 0.5 to 1.0 volts at idle, rising to 4.0 volts (or
more) with a fully opened throttle.” Should there be any complete drop off in voltage on the wave
form, then a problem has occurred. The driver would notice this in the form of a dead zone affect
under acceleration.
Figure 16: An example waveform starting at 0.5v [Throttle position closed]. (Pico Technology n.d.).
Knock Sensors
Knock sensors are fitted to the engine block to detect any vibrations, thus detecting engine/rod
knock. This is done by listening for certain pre-determined frequencies. It will then turn these
detections into an electrical signal input to the ECU.
It does this by use of three key components. A washer transmits the engine vibration through a
seismic mass which in turn transfers down to a piezoelectric ring. A series of contacts will connect
from here to a resistor from which the burdens may be downloaded. The electrical signal is then
passed on via a cable to the ECU. The ECU then determines the forces from the voltage of that
electrical signal and from there can determine the changes required for ignition timing, if any
changes are required at all.
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Although the sensor does not have input on the engine running, it is an essential safety to feature to
give the ECU the information required to counter any engine knock.
Lambda/O2 Sensors
Lambda sensors are sometimes known as O2 sensors and provide critical feedback for the ECU.
There are a variety of lambda sensors, wideband, Thimble and Planar, the latter two typically coming
in narrowband format. Recently, Thimble and Planar have become available in wideband, which is
more beneficial to motorsport. Wideband gives a larger feedback to the ECU.
Lambda sensors, in real time, relay the fuel to air ratio in the engine to the ECU. Thus, allowing
correction to the values in the engine matching the target values within the map itself.
A lambda sensor on most road cars will determine if the vehicle has a lean or high mixture by
measuring the exhaust gases from the car, this information is passed onto the ECU via an altering
voltage signal. This is accomplished by detecting the various level of oxygen on its sensor plates.
Each plate will have differing levels of oxygen and thus different voltage. This allows the ECU to
determine whether the engine is running on a Lean or High mixture.
Figure 17: A cut-out diagram of three types of Lambda sensors (Gordon, 2016).
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Actuators
Fuel Injectors
A fuel injector holds fuel at a specific pressure until the ECU sends a signal to spray the fuel into the
combustion chamber. The ECU controls both the timing of the injection and the pressure.
The fuel injector should only spray the fuel, to aid the engine in burning it.
The plunger will only open on command of the ECU for a certain amount of time, referred to as
pulse width. The injector will also receive a 12v signal from the ignition supply. On certain systems,
that don’t run pulse width, this can tie in with the Traction control system, as the injectors will run
on a constant voltage when everything is working correctly.
When the TC detects wheel slippage it will change the voltage sent back thus deactivating,
individually, each injector dependant on how much the TC deems necessary to rectify the wheel
slippage. This system is becoming more common in motorsport.
Boost solenoid
An electronic boost control solenoid is required to allow the boost pressure to be bled off from the
wastegate actuator, particularly the hose actuator. Certain actuators can be programmed to block
any pressure from reaching the wastegate actuator thus allowing for a more responsive turbo and
better boost control. The ECU will continue to control the Solenoid so that a constant update is
being carried out to achieve the desired boost pressure. This is done using pulse width modulation
and are optimal for use with standalone ECUs.
The input for the boost solenoid is either 5v or 12v depending on the make, the output is typically
between 1.5v on idle to 4.5v on max boost.
Maps
The ECU optimises car performance by using maps. Maps have target values for various engine
running processes. These are designed to optimise performance or potentially other goals such as
economy, seen more in road cars.
The ECU uses the various actuators and sensors to have a constant feed of the engine’s current
values in areas such as Boost, Fuel mixture, engine torque and many more. The ECU will use this
information to meet the target values within the map itself, like a runner using a smart watch to
monitor their BPM.
The more maps in the ECU the more sensors and actuators are required. This ECU will require an
ignition timing map, a boost map and a fuel map.
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Figure 18: Left hand picture showing a fuel XYZ graph. Right hand picture shows what a VE Table looks like when creating
the fuel map in the software. (Motorsport Electronics Ltd, 2019).
Control Diagrams
Figure 19: Main Control diagram with inputs indicating information ECU requires, outputs indicating where the information
is required, to action ECU demands.
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Figure 20: Ignition control, red indicates monitoring and where corrections will be carried out and by what.
Figure 21: Boost control in which the boost control solenoid updates from the ECU.
Figure 22: Fuel injection controlled by ECU and corrections made by the Lambda sensor and map in the ECU.
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Module 4
Task 5
Waveforms
Task 5A
Crank and Cam sensors
The first image from appendix 3 shows a single revolution of the crankshaft on a waveform. The blue
line indicates the voltage output. The red line above indicates the camshaft sensor. Circled in orange
are the output readings that indicate top dead centre. This allows the user to see the position of the
crankshaft during revolution.
Also in the waveform is an unusual dip in reading that is not consistent with the flow throughout.
This indicates that around the number 7 to 8 tooth, past TDC, there is potential damage, or there are
teeth missing. This would result in an inaccurate reading returning to the ECU that would likely
confuse it, and lead to the engine not running correctly thus causing damage. This is because the
ECU uses the data from the Crank sensor to time ignition and fuel injection, this would lead to the
engine running poorly or not at all.
The ECU potentially can use just the data received from the camshaft sensor; however, this would
likely soon not be accurate enough to keep the timing of the engine correct. Once this anomaly has
been discovered on waveform, it needs to be confirmed that there is indeed damage to the 7th and
8th tooth. The easiest way to do this would be to use a borescope, if that is not possible then the
reluctor ring would need to be removed for examination.
Figure 23: Orange circles indicating gap in reluctor ring teeth used to mark top dead centre. Red indicates broken or
damaged teeth.
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Task 5B
Lambda sensor
Normal
This waveform displays a normal running engine, shown by the continuous wave oscillations, formed
between around 0.1v and 0.9v. This means that the Lambda sensor is collecting the correct target
values set for normal running by the ECU. The engine will run normally, without excess fuel usage or
any potential damages that will be discussed on the other waveform diagrams.
Figure 24: Normal waveform output of a working lambda sensor Appendix 4.
Rich
In figure 25, the waveform of the lambda sensor indicates a rich mix. The rich mixture implies that
on this vehicle there is more fuel to air ratio found by the sensor in the exhaust gasses.
A rich mixture above the optimal ratio of 14.7 (Air) : 1 (Fuel) will lead to potential problems such as
bore wash. Bore wash occurs when a rich mixture leads to excess fuel not being burnt off and in
effect ‘washing’ the oil from the cylinder. This can lead to catastrophic damage as the metal-onmetal movement of the piston rings will damage the cylinder internals.
From a performance perspective, negative effects of rich fuel mixture can also lead to poor
acceleration and inefficient fuel usage. The spark plugs may also be affected, often being coated in
excess carbon, again leading to poor performance. Generally, the engine will run cooler with a rich
fuel mix.
Figure 25: Appendix 4 showing a rich reading Lambda sensor waveform.
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Lean
Figure 26 shows a lean mix waveform. As an opposite to rich running, the engine will tend to run at
much higher temperatures with a lean mix. This can lead to a lot of internal damage to components
such as valves, seals and multiple other components in the engine bay itself. In the worst case the
engine can seize or cut out, sometimes not even starting at all. This can often tie in with knock as a
lean mix and increased temperatures are more likely to induce knock. The increased temperature is
a cyclic effect, pockets of air become extremely hot when the fuel is ignited. This leads to
temperature increase which again leads to greater volume in these pockets of air. This premature
detonation will subsequently begin to damage the pistons. As this high temperature focuses on a
small area it can lead to a similar affect to bore wash, in that the heat evaporates the lubrication in
the chamber.
Figure 26 Showing a lean mix waveform from a lambda sensor appendix 4.
Broken Sensor
The sensor shown below looks like the working example in terms of shape and frequency of the
bands, however the voltage output is completely stuck in the middle without much variation. For the
lambda sensor to work correctly it needs to use its variable voltage output to give concise
information to the ECU. That way the ECU can get a clear reading of the richness or leanness of the
mixture. With a reading as below, the ECU is not getting any indication of any reading. This will lead
to the ECU being unable to adjust the fuel mixture to meet target values. Meaning an uncontrollable
rich mix, the effects of which have been discussed previously. With a broken sensor the likelihood of
mixture failure increases and will lead to subsequent damage.
Figure 27: a broken lambda sensor, showing little to no output voltage appendix 4.
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Task 5C
Appendix 5 (below) shows a good example of a fuel injector trace.
Figure 28: Appendix 5 showing a fuel injector trace waveform, the red circle indicates the pintle hump.
The fuel injector’s basic purpose is to spray an atomised jet of fuel to aid combustion at the correct
time in the engine cycle, into the cylinder head.
The fuel injector contains a pressurised fuel chamber. In one side pressurised fuel, the other side
contains the nozzle, with an electromagnetic coil controlling the movement of the fuel to the nozzle.
During normal operation, when the injector initiates the coil, it should use 12 volts. According to
(Markel, 2017) the coil is typically energized by a driver pulling the circuit to ground.
As the electromagnetic coil is saturated by energy, the pintle moves upwards against a spring.
Circled in red is the “Pintle hump” that indicates the injector closing. If the injector was to get stuck
in the closed position this would not be visible on the trace. The engine would likely run rough and
would cause misfires as fuel would not be delivered to the specific cylinder.
If the injector was stuck open, there would be a constant trace as the switch would be on. The
engine would likely flood, and the cylinder of the bore would have a wash affect. This is incredibly
damaging to the cylinder and would lead to rough running just as a closed injector would.
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References
A,SOHANE (n.d.)MAP sensor operation and MAP circuit diagram. [Online image] Available from:
https://cecas.clemson.edu/cvel/auto/AuE835_Projects_2013/Sohane_project.html [Accessed
29/08/2021].
AUTOSERVICEPROFESSIONAL (2016) Oxygen sensor cut-out. [Online image] Available from:
https://www.autoserviceprofessional.com/articles/1097-oxygen-sensor-heaters-how-do-you-knowif-that-heater-fault-code-is-real [Accessed 28/08/2021].
Darkside Developments (2018) Map Sensors Blog. [Online image] Available at:
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