POWER INCREASING MEASUREMENT AND ANALYSIS BASED
ON MODIFIED MECHANICAL SYSTEMS ADDED TO A
TURBOCHARGED INTERNAL COMBUSTION ENGINE
Submitted in partial fulfillment of the Requirements for the award of the degree of
MECHANICAL ENGINEER
By
Luis Felipe Navarro Rodriguez
Project Advisor
PhD, M.Sc Luis E. Muñoz Camargo
Los Andes University Bogotá, Colombia
ACKNOWLEDGEMENTS
A mi padre Ángel María Navarro Monsalve a mi madre Jackeline Rodriguez Carrillo y a mi hermana Laura Catalina Navarro Rodriguez por el apoyo incondicional en cada etapa de mi
vida.
También a mi Asesor Luis Ernesto Muñoz Camargo, por alentar y promover un proyecto de gran importancia y pasión personal.
1. ABSTRACT
One of the most interesting parts of building a machine is taking out the most amount of power it could give. As it is known, the vehicle industry has fought through the years to create powerful and faster cars, getting each year to the technological limit, ten years ago, talking of a road legal car with 600 Horsepower was impossible, but today we can talk of road legal cars with more than 1500 Horsepower. This document presents the analysis and measurement of the mechanical systems that can be installed on a turbo charged internal combustion engine, making possible the power increment of the present vehicles.
CONTENT TABLE
1. ABSTRACT ... 3
2. INTRODUCTION ... 8
3. OBJECTIVES ... 9
3.1. GENERAL OBJECTIVES ... 9
3.2. SPECIFIC OBJECTIVES ... 9
4. METHOD ... 10
4.1. INSTRUMENTS ... 13
4.1.1. Dyno-‐Dynamics Dynamometer ... 13
4.1.2. MAF Bosch (0280218063) ... 14
4.1.3. MAP Bosch (0281002401) ... 15
4.2. STOCK DATA ... 16
5. MODIFICATIONS ... 21
5.1. ADMISSION MODIFICATIONS ... 21
5.1.1.Cold Air Intake ... 21
5.1.2. Inlet ... 23
5.1.3. Front Mounted Intercooler ... 24
5.2. EXHAUST MODIFICATION ... 27
5.2.1.Downpipe ... 27
5.2.2. Cat-‐Back ... 28
5.3. ECU MODIFICATIONS ... 30
5.3.1. Etuners program system ... 30
6. RESULTS ... 31
6.1. DYNAMOMETER RESULTS ... 31
6.1.1. With Modified Admission ... 32
6.1.2. With Modified Exhaust ... 34
6.1.3. With Modified ECU program ... 36
6.2. QUARTER MILE RESULTS ... 38
6.2.1. With Modified Admission ... 38
6.2.2. With Modified Exhaust ... 39
6.2.3. With modified ECU program ... 40
7. ANALYSIS ... 42
7.1. BEST MODIFICATION SYSTEM ... 42
7.2. ADVANTAGES OF THE MODIFICATIONS ... 43
7.3. DISADVANTAGES OF THE MODIFICATIONS ... 45
7.3.1. Low cold air intake ... 45
7.3.2. Extreme Temperatures ... 45
7.3.3. Fuel Consumption ... 45
7.4. OTHER APPROACHES ... 46
8. SUMMARY ... 47
9. SUGGESTIONS ... 49
9.1. TECHNICAL SUGGESTIONS ... 49
9.2. COMPETITION SUGGESTIONS ... 49
10. FUTURE WORK ... 50
GRAPH LIST
GRAPH 1. POWER VS.TORQUE, STOCK ... 20
GRAPH 2. POWER VS. TORQUE, ADMISSION ... 34
GRAPH 3. POWER VS. TORQUE, EXHAUST ... 35
GRAPH 4. POWER VS. TORQUE, ECU ... 37
GRAPH 5. POWER INCREASE THROUGH THE MODIFICATIONS ... 43
GRAPH 6. TORQUE INCREASE THROUGH MODIFICATIONS ... 44
GRAPH 7. MAXIMUM VALUE FOR EACH MODIFICATION ... 47
TABLE LIST
TABLE 1. QUARTER MILE TRACK RESULTS ___________________________________________________________________ 16 TABLE 2. QUARTER MILE STOCK CONDITIONS _______________________________________________________________ 17 TABLE 3. SENSORS DATA _______________________________________________________________________________________ 18 TABLE 4. DYNAMOMETER STOCK DATA _______________________________________________________________________ 19 TABLE 5. DYNAMOMETER ADMISSION DATA _________________________________________________________________ 32 TABLE 6. OBDII ADMISSION DATA _____________________________________________________________________________ 32 TABLE 7. DYNAMOMETER EXHAUST DATA ___________________________________________________________________ 35 TABLE 8. DYNAMOMETER, ECU DATA _________________________________________________________________________ 36 TABLE 9. TRACK TIMES FOR NEW ADMISSION SYSTEM _____________________________________________________ 38 TABLE 10. TRACK CONDITIONS FOR ADMISSION TEST ______________________________________________________ 38 TABLE 11. TRACK TIMES FOR NEW EXHAUST SYSTEM ______________________________________________________ 39 TABLE 12. TRACK CONDITIONS FOR EXHAUST TEST. ________________________________________________________ 39 TABLE 13. TRACK TIMES FOR ETUNERS ECU PROGRAM _____________________________________________________ 40 TABLE 14. TRACK CONDITIONS FOR ECU TEST _______________________________________________________________ 40
FIGURE LIST
FIGURE 1. FOUR-‐STROKE ENGINE CYCLE _____________________________________________________________________ 11 FIGURE 2. VEHICLE SELECTION (VOLKSWAGEN JETTA GLI 1.8T 2012) _____________________________________ 12 FIGURE 3 DYNO-‐DYNAMICS 450DS SPECIFICATIONS ________________________________________________________ 13 FIGURE 4. DYNO-‐DYNAMICS DYNAMOMETER ________________________________________________________________ 13 FIGURE 5. MAF SENSOR _________________________________________________________________________________________ 14 FIGURE 6. MAP SENSOR FRONT VIEW _________________________________________________________________________ 15 FIGURE 7. MAP SENSOR _________________________________________________________________________________________ 15 FIGURE 8. TURBO CHARGER K03 BORGWARNER _____________________________________________________________ 17 FIGURE 9. STOCK INTAKE ______________________________________________________________________________________ 21 FIGURE 10. STOCK INTAKE VS. FORGE INTAKE _______________________________________________________________ 22 FIGURE 11. FORGE INTAKE _____________________________________________________________________________________ 22 FIGURE 12. STOCK INLET _______________________________________________________________________________________ 23 FIGURE 13 STOCK INTET VS. FORGE INLET ___________________________________________________________________ 23 FIGURE 14. FORGE INLET _______________________________________________________________________________________ 24 FIGURE 15. STOCK INTERCOOLER _____________________________________________________________________________ 25 FIGURE 16. STOCK INTERCOOLER VS. JDM INTERCOOLER ___________________________________________________ 26 FIGURE 17. FINAL ADMISSION MODIFICATIONS ______________________________________________________________ 26 FIGURE 18. STOCK DOWNPIPE _________________________________________________________________________________ 27 FIGURE 19. THREE INCH DOWN PIPE _________________________________________________________________________ 27 FIGURE 20. STOCK CAT-‐BACK __________________________________________________________________________________ 28 FIGURE 21. THREE INCHES CAT-‐BACK ________________________________________________________________________ 28 FIGURE 22 STOCK CAT-‐BACK VS. THREE INCHES CAT-‐BACK ________________________________________________ 29 FIGURE 23. STAGE 2 FROM ETUNERS __________________________________________________________________________ 30
2. INTRODUCTION
Through the time, the human being has always tried to improve every system that he has had developed, specifically the automotive industry in which every company takes in to account some important factors that will help them to sell millions of vehicles worldwide, which are the looks, the horsepower and the torque that each model can deliver. So for a company to be able to create a greater income, they create a base model with a base price, and later that year they launch the same base model but with performance modifications and ask twice the price of the base model, for example, the Ford Fiesta and the Ford Fiesta ST, The Subaru Impreza and the Impreza STI, the Volkswagen Golf and the Golf GTI. But the modifications to this base models some times are very simple and can be made by the owner of the vehicle without having to pay the double of the price tag. That’s why the intention of this document is to show which are the systems that you need to install to your vehicle and how they work, to increase the power and the torque at the level of the race model of the brand and saving money at the time.
3. OBJECTIVES
3.1. General objectives
o To analyze and measure the performance increment of a turbocharged internal combustion engine caused by mechanical or electrical modifications to the air admission, the exhaust system and the engine control unit (ECU), based on a methodological process that can be applied to a specific case, with track and dynamometer tests.
3.2. Specific objectives
o To determine the torque and power increment graphs that shows the engine behavior and its response to each modification.
o To measure the quarter mile performance increment represented on the final speed and time for each modification.
o To analyze the effects of each modification on the track times and the dynamometer graphs.
4. METHOD
The intention of this project is to answer one of the most asked questions of a motor head, how can I modify my car and get from its engine the most amount of power? This question has been in everyone’s head, but there is a reason why, to this day, there is not an exact answer to that question. It is all based on the money someone has to expend to know which are the best ways to modify a car, taking into account that the automotive market is one of the most expensive in the world.
A big company like Ferrari, has done a lot of research on the way to get each engine to its maximum potential with the big advantage of owning different formula race teams to test them, they clearly know the answer to everyone’s question, but they will not share the information, because they have spend large amounts of money to acquire that knowledge and create a single and profitable market, and so it goes with different brands that have a very complex “know how”.
In this project would be explained the principal modifications to an internal combustion engine with a turbocharged, taking into account the way a four-stroke engine works as shown on the Figure 1. Four-Stroke Engine Cycle. It all stars at the admission of the air to the cylinders, this step is called “Intake” in which air comes in and the fuel is injected, in this step there are different aspects to be modified, you can increase the amount of air that enter in to the chamber, you can also increment the amount of fuel that enter in to the chamber or you can decrease the temperature of the air coming in, to have air with a higher density.
At the second step, the cylinder will compress the mixture that you have developed in the step before, this compression increments the performance of the car in the way you increment the pressure of the mixture inside the chamber, as a reaction of the compression the spark plug will be activated so the combustion takes action and forces the piston to go down which cause the motion of the crankshaft of your engine.
Figure 1. Four-Stroke Engine Cycle (Snout)
The final step will be the determined by the way mixture goes out of the chamber, in this step you can also do modifications to increment the power output of your engine, as the piston goes up, the mixture is forced to escape through the exhaust, but there is a force against it, called back pressure, in witch the mixture cant go through the exhaust as fast as it can because the area in which it flows isn’t big enough.
As a result of the way a four-stroke engine works, there are three basic modifications you can make to it taking into account the order of the steps explained, First it would be necessary to modify the air admission system, which is composed by the air filter (intake), the inlet and the Front mounted intercooler.
account its two main parts, the down pipe and the Cat back. In addition to it, the catalyst system will be removed to improve the flow of exhaust gases.
The third and final modification will be done to the programming of the ECU (electronic control unit), which manages the amount of air and fuel injected to each cylinder of the vehicle, as well as the timing of the spark plug. With this modification the way an engine runs can be modified easily from a computer taking into account different aspects of the race you are in as wheels, fuel, weight and atmospheric pressure.
To test the way these modifications affect an internal combustion engine, each of them will be done in this project to a Volkswagen Jetta GLI that has a turbocharged engine that work with the same principles of a four-stroke cycle. Each modification will be measured on a dynamometer to check the horsepower and torque curves, also on the quarter mile track time to have a real dimension of the increasing performance of the vehicle, were the main aspects that will be reviewed are the maximum power at the wheels for each modification, the maximum torque for each dynamometer test and an average of the quarter mile times.
4.1. Instruments
The uncertainty for each instrument was calculated experimentally based on the OBDII data, the dynamometer Graphs and the quarter mile times and speeds.
4.1.1. Dyno-Dynamics Dynamometer
Figure 3 Dyno-Dynamics 450DS Specifications (Dyno dynamics specifications brochure, 2016)
The front wheel drive Dynamometer 450 Ds was used on the experimentation, as there is no information available on the uncertainty or accuracy of the system, these values were experimentally calculated. This dyno has a 96 tooth and a 0,21 [m] diameter on the flywheel, and has an experimentally uncertainty of ± 0,7 Units for each torque and Power Graphs.
4.1.2. MAF Bosch (0280218063)
The MAF (mass air flow) sensor of the Volkswagen can measure the way temperature and weight of the air is coming in to the cylinders of the engine, is placed between the intake and the inlet, all the these information is processed by the ECU to calculate the amount of air and fuel that it needs to keep running.
It has an integrated system with a hot wire element that is protected with a previous filter so dust particles can’t damage it, this wire is at a constant temperature but when the vehicle accelerates, the air pass though it dropping it down, this can be related with ohms equation:
Figure 5. MAF sensor (Bosch, 2015)
𝐼 =𝑉
𝑅
Taking into account that the current is represented by I, the Resistance value by R and the Voltage by V. for the MAF to maintain the wire at a constant temperature it relates the Temperature with the resistance so when the value for the Resistance is dropping, the current needs to increase to keep the steady system, its has an accuracy of ± 3% [Dm/m] and ± 0,1 [g/s].
4.1.3. MAP Bosch (0281002401)
The MAP (manifold absolute pressure) works with the same principles of the MAF, its placed between the Cold Air Intercooler and the Manifold, it can determine the pressure that is entering to the cylinders so the ECU can calculate the amount of air and fuel to let into the chambers.
Figure 6. MAP sensor Front view (Bosch, 2015)
Figure 7. MAP sensor (Bosch, 2015)
It works by the use of a sealed chamber with a silicon chip that is flexible and have a current passing though it, so using again the Ohm`s Law, it can relate the resistance value change to determine the absolute pressure that the cylinders are taking in. it has an accuracy of ± 1,5 KPa and a rated resistance of 2,5 ± 5% [KOhms].
4.2. Stock Data
Based on the previous information, the stock data of the vehicle must be exposed to have a comparison point with the further modifications, there will be done 5 rounds for the track test in which the reaction time of the driver will not be took into account in the final quarter mile time.
For the dynamometer test it will be done 5 rounds too, but will only be exposed the one with the higher power and torque output so the reader can see the best performance it can produce.
Here are the quarter mile tests for the stock configuration:
Quarter Mile Track Test, Stock
Test # Reaction [s] 60ft [S] Speed [km/h] Time [s] 1 0,684 2,794 147,3 17,106 2 1,218 2,828 147,8 17,108 3 0,694 2,765 147,5 17,098 4 0,99 2,771 149,2 17,109 5 0,862 2,814 148,4 17,208 Average 0,88 2,79 148,0 17,12
Variance 0,03 0,0005 0,4 0,001
Standard Dev. 0,22 0,02 0,7 0,046 Table 1. Quarter mile track results
The most important values to observe are the 60 ft time, which reflect the amount of torque the vehicle can produce to perform a launch from the start, the Speed, that shows the development of the power to the wheel through the track, and the time, that determine if the modifications have made result on the performance of the vehicle.
As you can see, it has a stock quarter mile of 17,12 [s] at 148 [Km/h], which is comparable to the Mini Cooper SD Paceman and the Audi A3, values that comes from the same track and conditions of the volkswagen, a great quarter mile for a small 4-cylinder vehicle with a small K03 Turbo BorgWarner.
Figure 8. Turbo charger K03 BorgWarner (BorWarner)
This turbo is placed in different vehicles of the Volkswagen group, for its compact size and great full output power; at its compressor wheel it has a 33,6[mm] inducer, a 46[mm] exducer diameters, and a tip height of 3,7[mm]. At its Turbine wheel it has a 45[mm] inducer, a 38 [mm] exducer diameter and a tip height of 6,8 [mm]. Using 11 blades to increase the output power of the engine it’s connected to, as it is indicated on the specifications of the turbocharger.
Taking into account that the performance of the turbo and the engine can be affected by the conditions, here is a table witch some of the variables measured for every test:
Quarter Mile Track Test Conditions, Stock
Test # WS [m/s] RH [%] T [ºC] Tt [ºC] Ap [KPa] 1 0,4 73 14,6 23,2 77 2 0,3 70 14,3 27,1 77 3 0,6 75 13,1 28,5 77 4 0,6 78 12,3 25,4 77 5 0,5 79 11,4 27 77 Average 0,48 75 13,14 26,24 77
Variance 0,01 10,8 1,44 3,27 0
Standard Dev. 0,13 3,67 1,34 2,02 0 Table 2. Quarter mile stock conditions
o WS = Wind Speed o RH = Relative Humidity o T = Temperature
o Ap = Atmospheric pressure
All of the track tests were done starting at 8pm on the autodrome of Tocancipa, Cundinamarca, so the values of the atmospheric pressure are always the same, as you can see, temperature on the table 2. is dropping through the tests, which reflects the time passing through the night making a colder ambient also affecting the relative humidity of the ambient.
At the same time, OBDII data was recovered from the ECU of the vehicle to determine the values of the MAP and MAF shown in the Table 3.
Maximum data acquired by OBDII Port MAF [g/s] MAP [Kpa] Intake [ºC]
105,5 182 39-‐69 Table 3. Sensors data
These values are going to be useful to create a comparison of the air that comes in to the cylinders for the modifications of the air admission system, because the temperature of the intake should be lower, and de pressure that the MAP reports can be a tool to determine the pressure that the turbo charger is doing.
Besides this, more data was acquired by the dynamometer to be compared with the modifications, as you can see on the Table 4, and more easily reflected on the graph 1, in which toque and power are shown into one graph, the principal curves of the engine and how is it working through the revolutions range, For a more friendly lecture of the table, torque data is presented en newton meters, and in pounds foot.
Dynamometer data, Dyno dynamics [Stock]
RPM Torque [LbFt] Torque [Nm] Power [Hp] 2200 97 131,5 43 2500 127 172,2 65 2750 156 211,5 78 3000 169 229,1 93 3250 183 248,1 113 3500 196 265,7 128 3800 197 267,1 143 4000 194 263,0 148 4250 190 257,6 153 4500 183 248,1 158 4750 174 235,9 158 5000 168 227,8 159 5250 157 212,8 156 5500 150 203,4 156 5750 145 196,6 158 6000 139 188,4 159,7 6250 130 176,2 155 6500 120 162,7 153
Max 197 267,1 159,7
Table 4. Dynamometer stock data
The most important values of this table are the maximum torque and the maximum power, were they reach their greatest value at 267, 12 [Nm] and 159,7 [Hp], taking into account that this results were obtained at high altitudes with low atmospheric pressure, 2640 [m] and 1026 [hPa], and that the power given has loses on the crank, clutch and transmission, so the value is calculated to the wheels.
In the next graph it can be observed the way the stock engine of the Volkswagen Jetta developed their power, having a slow increment until the turbo charger comes in with a higher pressure at 3,100 [RPM] it maintains its value around 157 [Hp] though 4250 all the way to 650 [RPM].
Graph 1. Power Vs. Torque (Pope, 2009) (Ademola, 2009; Casal, 2014; PECIURA, 2014; Kristoffersson, 2006; BorWarner), Stock
On the other hand the torque curve reaches it maximum value at a high value of revolutions (3800 RPM) which shows a safe development of the engine by Volkswagen, not taking any chances for it to cause a malfunction or exceed their limits, and this is done thanks to the ECU stock Program in which they limit some aspects of the vehicle such as the turbo pressure and the maximum speed of the vehicle set at 210 Km/h.
Using this data as a base to the development of the project, its very interesting to know if the increment of this curves its going to be significant, or by the other side all the modifications done are just going to produce a minor increment of the output power and torque of the engine.
This modifications can be very expensive if you choose to buy from some tuning brands, but in this project I will show you that sometimes, is better to do the modifications by yourself and save larges amount of money for importation and installation.
0 50 100 150 200 250 300 350
2200 2500 2750 3000 3250 3500 3800 4000 4250 4500 4750 5000 5250 5500 5750 6000 6250 6500 RPM
Volkswagen Jetta GLI Stock
Torque [Nm]
5. Modifications
This chapter contains all the process of modification for the three systems, admission, Exhaust and ECU programming in which each one shows the stock and the tuning aspects of the installation. As well as a physical differentiation of the system installed to the Volkswagen.
5.1. Admission Modifications
As explained at the beginning the first step to increment the power of an engine is by introducing a colder and higher amount of air to the cylinders. The parts that form the admission of an internal combustion engine are the intake, the Inlet, and the front mounted intercooler.
5.1.1.Cold Air Intake
A cold air intake is use to obtain cold air air to the engine, because it has more density than the hotter air, as you can see on the stock intake image, the air filter is covered with a black case and is placed next to the engine, this means that when the car is running, engine it´s going to heat everything near it, including the filter causing the heat up of the stock intake.
Fortunately there is a solution, you can remove the stock filter, and replaced it with a Forge Cold air intake, as you can see on the Figure 10. The forge filter has a longer pipe to take the conic filter right next to the wheel, were it can take the outside air that is colder tan the air close to the engine.
Figure 10. Stock intake Vs. Forge Intake
The amount of air that is coming into the engine is also increased, without mentioning that the sound of a cold air intake is increased due to the pressure increment. On the other side, it can be seen that the materials of the pipe line for the intake are from carbon fiber, which means that the air that flows through the pipe wont be heated up by the heat of the engine as much as the older intake. Finally you can see how the system looks installed on the figure 11. Leaving a big space and letting a better view of the engine components.
5.1.2. Inlet
The inlet is a very important hose that connects the cold air intake to the turbo charger, its also the union of the Front mounted intercooler and it has connected different pressurized turbo systems like the diverter valve. The stock inlet is placed on an area that is difficult to see because the turbocharger is connected behind the engine.
Figure 12. Stock Inlet
As it can be seen on figure 13, there are some important differences between the stock and modified inlet, for example, the end that connects to the turbocharger is originally of steel, but the one from forge it´s all made by rubber, other significant difference is the diameter of the hose, which is bigger on the forge.
Finally, after the installation, you can observe the way it connect the different hoses of the system on figure 14. Tanks to this hose the air will stay cold, as it comes though the pipeline to the turbocharger, because previous inlet heated up the air with the steel at the end of the connection.
Figure 14. Forge inlet
5.1.3. Front Mounted Intercooler
The intercooler of a turbocharged engine is one of the most important systems of the vehicle because it´s in charge of cooling down the air that comes through the turbo to the engine cylinders, as it is known when a fluid is compressed like on the turbo charger, he temperature increases drastically, is this why the air need to pass through the intercooler before entering to the manifold.
Based on the ideal gas law, we can determine the density of the air and how temperature affects it as shown in the next equations (Cengel) (Etuners):
𝑃𝑉 = 𝑛𝑅𝑇
𝑃𝑉 = 𝑚 𝑀𝑅𝑇
𝑃𝑀 = 𝑚 𝑉 𝑅𝑇
𝑃𝑀 = 𝜌𝑅𝑇
𝜌 =𝑃𝑀 𝑅𝑇
Knowing that the density of a gas is determined by it´s temperature and pressure, the variable that we can change will be the temperatures, as they are proportionally inverse, when the temperature rises, the density gets lower, and when the temperature is low, the density increases.
Figure 15. Stock intercooler
A bigger area will be needed to create a bigger drop on the temperature that comes in to the manifold, as you can see on the figure 15, the stock intercooler is placed in front of the front right tire, but as the new intercooler need a higher flow, the front of the vehicle is more suitable for this situation.
Figure 16. Stock intercooler Vs. JDM intercooler
After installing the after market intercooler, in the front of the vehicle including a pipeline with a 2,5 in diameter to increase the flow area in which the air passes through, a notable result must come out of this modification due to the heat exchanger.
Figure 17. Final admission modifications
Finally after modifying all the admission system, it can be seen on the figure 17. The way the Volkswagen has change to create an increment on the power and torque output. It can be expected that the quarter mile times are going to drop as the amount of air to the cylinders has increase and the temperature of the gas has dropped to it´s maximum value.
5.2. Exhaust Modification
The exhaust modification is the second big step to obtain a high power turbo charged internal combustion engine. There are two main parts of the exhaust, the down pipe and the cat-back, this entire pipeline determines the backpressure of an engine, and the way the gas flows to the exterior of the vehicle depending.
5.2.1.Downpipe
The downpipe, connects the turbine of the turbo charger and the cat-back of the vehicle, it is known for having a catalyst system in it, which is shown on the figure 18. And it is made from steel, collecting some corrosion through the years, that's why it looks orange.
Figure 18. Stock Downpipe
The best way to release the backpressure of the engine, so it can have a steeper torque curve, it is by increasing the diameter of the pipe line and taking out all the obstructions to the exhaust gases flow such as the catalyst system and the muffler, but as a consequence it will only be able to be driven at the race tracks due to the CO emissions increment.
As shown in the figure 19, a three inches of diameter down pipe was installed, it’s made from stainless steel, to avoid corrosions, and increases the flow rate of the exhaust gases as the same time releases the back pressure at the last step of the four stroke cycle.
5.2.2. Cat-Back
The cat-back is the pipe line of the exhaust that is placed behind the catalyst system, that is why it is named “cat-back”, as shown in the figure 20, the stock cat-back has a two inch diameter, a presilencer is placed at the beginning of the pipeline to reduce noise and a muffler at the exit.
Figure 20. Stock Cat-Back
The same principle as used on the downpipe is used on the cat-back, in which a three inches pipeline is used in stainless steel as shown on the figure 21, the presilencer was removed to improve the flow of the exhaust gases, an a direct muffler was installed to let the gases pass through it without difficulties.
Finally it can be seen the difference of diameter and materials for each pipeline on the figure 22, to create a higher speed of the exhaust gases though it, this specific modification will increase de volume of the sound that comes out of the vehicle to son unnecessary levels that can disturb the ears of some people, so it is advised that this modification can only be done to a track only car like this Volkswagen Jetta.
5.3. ECU Modifications
The ECU modification is the last step of the three main modifications, this modification has no mechanical system included or replaced, it is done by connecting a tuning company computer to de OBDII port downloading a new program data to the computer of the car. 5.3.1. Etuners program system
Etuners is a tuning company created in Sydney, they have created their own maps for the Volkswagen Jetta including some interesting systems such as launch control, antilag and No lift shift. Although they don't give the information of what exactly do to the programming of the ECU there are several changes that are notable by the OBDII port.
Figure 23. Stage 2 from Etuners
The boost pressure of the turbo charger is increased to 20 PSI, the amount of fuel injected to the cylinders also is increased and some electronically limitations are removed, such as the top speed. One of the most interesting systems added is the anti-lag, which eliminates the lag of the turbo between gear shifting.
The antilag system starts working at the peak range of the power output, in which at the moment the clutch is pressed by the pilot, the spark plug timing is modified, letting the combustion takes place out of the cylinders, forcing the turbine to maintain the spool up even when the acceleration pedal is not pressed (Etuners).
6. Results
In this chapter is going to be exposed all the dynamometer and quarter mile results, taking into account that for each configuration, five tests were done at the track and at the work shop. For the power and torque graph, it’s going to be shown the best performance of the stage (level of modification) in which the vehicle is, and for the quarter mile, it`s going to be shown all the five runs at the autodrome, using as reference point the probabilistic functions, average and Standard deviation.
6.1. Dynamometer Results
The process of testing the performance of a turbo charged internal combustion engine, based on modifications done to the vehicle is very interesting, to see the evolution of the curves along the time and feeling the difference on track when driving all out.
The process of a dynamometer test it`s very simple, you first take the front wheels of the vehicle to the rollers of the dynamometer (Remembering that the Volkswagen Jetta is a front wheel drive vehicle), then make sure all the save points of the system are strapped to the vehicle, then start the engine and make sure that the vehicle is aligned with all the system. The front wheel must be pumped up to a pressure in which all the torque is completely passed to the rollers, and minimize losses at the wheels.
For each stage the wheels pressure was 45 [PSI], then the relation for the transmission and vehicle speed was set for the fourth gear because it's the gear in which the test took place, were 3000 [RPM] corresponds to 100 [Km/h]. Finally five runs with 100% admission were done with 30 seconds apart from each one.
The deviation was experimentally calculated for the torque and power graphs with a value of ± 0,74 units that its not going to be showed on the graph because its not significant.
6.1.1. With Modified Admission
For the first stage of modification, in which the cold air intake, the inlet and the front mounted intercooler were installed, the results show a great improvement for the output power and the torque, with a maximum value of 185,1 [Hp] and 284,7 [Nm] as it can be seen on the table 5.
Dynamometer data, Dyno dynamics [Admission] RPM Torque [Lbft] Torque [Nm] Power [Hp] 2200 101 136,9 64 2500 141 191,1 74 2750 169 229,1 86 3000 183 248,1 106 3250 204 276,6 127 3500 205 277,9 137 3800 209 283,4 152 4000 210 284,7 158,5 4250 206 279,3 165,5 4500 204 276,6 172,5 4750 198 268,4 180,5 5000 193,5 262,3 183 5100 190 257,6 185,1 5500 171 231,8 179,5 5750 168 227,8 183 6000 162 219,6 183 6250 151,5 205,4 180 6500 141 191,1 175
Max 210 284,7 185,1
Table 5. Dynamometer Admission data
Based on table 4, were stock data was shown, it can be seen a 15,9% increment on the power at the wheels, and a 6,6% increment on the Torque, which means that the modifications to the admission system were effective.
Maximum data aquired by OBDII Port MAF [g/s] MAP [Kpa] Intake [ºC]
By observing the values for the temperature range at the intake on table 6, it can be inferred, that colder air is coming in to the engine cylinder, and to calculate the percentage of air mass included to the cylinder, its necessary to use the ideals gas law.
The minimum temperature of the air with the stock intake was 39ºC, and the minimum temperature of the intake with the Forge intake was 24ºC, so we can calculate the density at which air is coming into the inlet (Cengel).
For air at 39ºC
𝜌!"#$% = 𝑀𝑃
𝑅𝑇 =
28,97𝑔𝑠 ∗0,78𝑎𝑡𝑚
0,082𝑚𝑜𝑙𝐾𝐿𝑎𝑡𝑚∗312,15𝐾= 0,88 𝑔 𝐿
For air at 24ºC
𝜌!"#$%%$&' =𝑀𝑃 𝑅𝑇 =
28,97𝑔𝑠 ∗0,78𝑎𝑡𝑚
0,082𝑚𝑜𝑙𝐾𝐿𝑎𝑡𝑚∗297,15𝐾=0,92 𝑔 𝐿
Tanking into account that the atmospheric pressure used to calculated the value was at Bogota Colombia, by doing this three simple modifications to the admission system was improved and let 4,5% more air mass in.
Finally the new characteristic curves of the Volkswagen Jetta are shown on the Graph 2, were the greater increase was made to the horsepower curve because the combustion of the engine was affected in a better way to make it more explosive, but on the on the other hand, it can be observed that the torque curve comes down to early.
This is caused by the great amount of air but the small amount of exhaust gases that can be expelled from the exhaust pipeline, is this why its necessary to do the modifications to the exhaust system so the engine can be relive from the back pressure the stock exhaust is making.
Graph 2. Power Vs. Torque, Admission
6.1.2. With Modified Exhaust
For the second modification stage in which the cat-back and downpipe were changed, these are the main values for all the RPM range, which are surprisingly better than the stock values, making now a top output Power value of 204,7 [Hp] and a Torque max value of 302,3 [Nm].
On the Table 7, can be seen that the admission modifications united with the exhaust modifications let a better development of the engine passing the 200 horsepower units and the 300 Newton meters barrier, what can let someone to ask, why do the main companies produce their vehicle with that much limitations, if the engine can hold more torque and power? This question can be answered on future investigations.
0 50 100 150 200 250 300 350
2200 2500 2750 3000 3250 3500 3800 4000 4250 4500 4750 5000 5100 5500 5750 6000 6250 6500 RPM
Volkswagen Jetta GLI modiRied Admission
Torque [Nm] Power[Hp]
Dynamometer data, Dyno dynamics [Exhaust] RPM Torque [Lbft] Torque [Nm] Power [Hp] 2200 105 142,3 66 2500 145 196,6 76 2750 176 238,6 94 3000 206 279,3 115 3250 214 290,1 134 3500 220 298,3 149 3800 223 302,3 161 4000 221 299,6 168 4250 218 295,6 177 4500 216 292,8 187 4750 212 287,4 193 5000 206 279,3 198 5100 200 271,2 200 5500 188 254,9 201 5750 182 246,7 203 6000 174 235,9 204,7 6250 164 222,3 201 6500 161 218,3 199
Max 223 302,3 204,7
Table 7. Dynamometer Exhaust Data
On the next graph can be seen the relation between the power and the torque, taking into account that both of the systems are installed, admission and exhaust.
0 50 100 150 200 250 300 350
2200 2500 2750 3000 3250 3500 3800 4000 4250 4500 4750 5000 5100 5500 5750 6000 6250 6500 RPM
Volkswagen Jetta GLI ModiRied
Exhaust
Torque [Nm]
6.1.3. With Modified ECU program
The data recovered from the last modification, the reprograming of the ECU with the company Etuners, shows an impressive out put of horsepower and torque, which can be seen on the table 8.
Dynamometer data, Dyno dynamics [ECU StageII] RPM Torque [Lbft] Torque [Nm] Power [Hp] 2200 106 143,7 68 2500 143 193,9 78 2750 172 233,2 96 3000 210 284,7 117 3250 230 311,8 144 3500 233 315,9 156 3800 238 322,7 174 4000 240 325,4 185 4250 242 328,1 198 4500 245 332,2 209 4750 242 328,1 218 5000 237 321,3 227 5100 236 320,0 231 5500 224 303,7 234,7 5750 203 275,2 220 6000 188 254,9 217 6250 178 241,3 212 6500
Max 245 332,2 234,7
Table 8. Dynamometer, ECU Data
This information shows the latest data with the combination of the three main modifications done to a turbocharged internal combustion engine, reaching a maximum power output of 243,7 [HP] and an impressive 332,2 [Nm].
Taking this into account, this modifications can affect the performance of a vehicle on a major way, increasing the output power on a 31,95% from stock and a 19,59% output torque from stock.
Graph 4. Power Vs. Torque, ECU
By observing the graph 4, it can be seen that the torque curve is longer maintained through the revolutions range, in comparison to the previous graphs, which means that increasing the air and fuel in the internal combustion chamber combined with a colder air admission and a higher exhaust flow is represented on constant torque outlet.
The power curve shows a different behavior than the previous graphs, represented on an earlier reach of the peak power a 5500 revolutions per minute, which shows the difference of the basic states were power peak is reached at least at 6000 revolution per minute.
0 50 100 150 200 250 300 350
2200 2500 2750 3000 3250 3500 3800 4000 4250 4500 4750 5000 5100 5500 5750 6000 6250 RPM
Volkswagen Jetta GLI ModiRied ECU
Torque [Nm] Power [Hp]
6.2. Quarter mile Results
Knowing the theory of how each system of the vehicle works, and how it preforms on the dynamometer, is time to know if those changes are really effective on the track. Fore some companies, the numbers of the quarter mile are very important information because it can determine the decision of a new buyer or fulfill the needs of a new market of the automotive industry. The total Deviation of the time measurements is not going to be included because they are not significant.
6.2.1. With Modified Admission
On the graph 2, can be seen a the way the power curve has a greater improvement than the torque one, this can be observed on the track times represented to the Table 9, in which quarter mile time was improved from stock, resting 0,3 [s] on the overall average time.
Quarter Mile Track Test, Modified Admission
Test # Reaction [s] 60ft [S] Speed [km/h] Time [s] 1 0,54 2,624 151,2 16,87 2 0,93 2,745 150,8 16,90 3 1,63 2,733 152,1 16,86 4 0,74 2,693 151,7 16,84 5 0,64 2,678 150,9 16,97 Average 0,90 2,694 151,39 16,89
Variance 0,15 0,001 0,243 0,001
Standard Dev. 0,43 0,04 0,55 0,04 Table 9. Track times for new admission system
Quarter Mile Track Test Conditions, Modified Admission
Test # Ws [m/s] RH[%] T [ºC] Tt [ºC] Ap [KPa] 1 0,3 67 13,3 23,4 77 2 0,4 66 13,2 28,7 77 3 0,3 69 13,3 28,5 77 4 0,5 70 12,9 29,6 77 5 0,4 69 12,8 28,5 77 Average 0,38 68,2 13,1 27,74 77
Variance 0,005 2,16 0,04 4,87 0
Without taking into account the reaction time of the pilot at the quarter mile, the 60 foot time represent how the torque curve is developed into de first and second gear, and how the car was able to put down the power to the track floor, with the air admission modification the driver was able to rest a 0,1 [s] to the 60 [ft].
As it can be seen, the variance from the data for the final time of the quarter mile has a very small value of 0,001 [s], which means that the new intercooler is maintaining the performance of the vehicle through each race.
6.2.2. With Modified Exhaust
With the new configuration of the vehicle, and the release of the back pressure from the stock exhaust, the main value to be observed on this stage, is the final speed of the vehicle because it shows how the engine developed on the high revolutions, being able to reach 156, 8 [Km/h], 8,71 [Km/h] more than the stock run.
Quarter Mile Track Test, Modified Exhaust
Test # Reaction [s] 60ft [S] Speed [km/h] Time [s] 1 0,78 2,643 156,1 16,59 2 0,62 2,573 155,9 16,53 3 0,51 2,598 157,4 16,59 4 0,95 2,613 158,2 16,61 5 0,84 2,604 156,3 16,52 Average 0,74 2,606 156,80 16,56
Variance 0,02 0,0005 0,758 0,001
Standard Dev 0,17 0,02 0,97 0,03 Table 11. Track times for new exhaust system
Quarter Mile Track Test Conditions, Modified Admission
Test # Ws [m/s] RH [%] T [ºC] Tt [ºC] Ap [KPa]
1 0,5 82 13,8 23,5 77 2 0,7 88 13,7 24,5 77 3 0,6 92 13,8 23,2 77 4 0,6 93 12,7 25,4 77 5 0,7 95 10,9 24 77 Average 0,62 90 12,98 24,12 77
Variance 0,005 21,2 1,25 0,60 0
As you can see on the Table 12, the conditions of Tocancipa`s autodrome, shows very high values of relative humidity, which can affect the temperature of the tires, causing a decrease on the grip of the tires for the launch.
Another important result is shown in the Table 11, were the time improved more than half a second than the stock run, what can be understood as a real improve of the admission and exhaust modifications.
6.2.3. With modified ECU program
The last track test was one of the most important modifications, the new ECU program, which include the launch control and the no lift shift system, which allows the driver to up shift without having to remove the foot from the accelerator pedal. On Table 13, can be seen the average quarter mile of 1 second less than the stock configuration.
Quarter Mile Track Test, Modified ECU
Test # Reaction [s] 60ft [S] Speed [km/h] Time [s] 1 0,72 2,632 159,9 16,11 2 0,54 2,593 161,1 16,07 3 0,97 2,574 160,9 16,00 4 0,67 2,589 162,7 16,00 5 0,78 2,602 160,6 16,10 Average 0,736 2,598 161,09 16,06
Variance 0,024 0,0004 1,041 0,003
Standard Dev 0,15 0,02 1,02 0,05 Table 13. Track times for Etuners ECU program
Quarter Mile Track Test Conditions, Modified ECU
Test # Ws [m/s] RH [%] T [ºC] Tt [ºC] Ap [KPa]
1 0,5 65 14,1 23,3 77 2 0,4 66 14,1 28,7 77 3 0,4 72 13,6 24,2 77 4 0,5 80 13,2 23,5 77 5 0,6 83 12,2 22,8 77 Average 0,48 73,2 13,44 24,5 77
Variance 0,007 65,7 0,623 5,765 0
Standard Dev 0,08 8,10 0,78 2,40 0 Table 14. Track conditions for ECU test
For time conditions with that high relative humidity and low tire temperature, this times can be improved with better conditions of atmospheric pressure, but taking into account that the modifications can be done easily in less than a month, it is able to lower a vehicles quarter mile time lower more than a second.
Finally it can be observed that he maximum speed reached at the end of the race is 161,1 [Km/h], 13 [Km/h] more than the stock configuration. Another important value is the way torque is developed on the first 60 ft, which shows a bigger Variance but a mucho lower value than the stock configuration.
7. Analysis
Knowing how to modify a four-stroke engine, its three main steps, the track and dynamometer results, is easy to do a relation of the concepts and the experimentation, taking into account that these modifications can be done to a turbocharged internal combustion engine.
This chapter will show the relation between each of the modification an the way their characteristic curves relate, also some concerns are going to be solved, such as the advantages and the disadvantages of the modifications, understanding that some of them can be dangerous for the longevity of the engine life.
7.1. Best Modification System
Choosing the best modification system is not easy because as the results provide, is the combination of them that could took out the maximum performance of the Volkswagen engine, but less review one by one to understand which is the best one.
The modifications of the admission system (intake, inlet and FMI) can cost around 3,000 $ without taking into account the installation cost, and its modification leads to a mandatory modification of the exhaust because, back pressure can affect the performance of the vehicle. On the other side, if only the exhaust system modification is installed, a lot of backpressure will be released but the amount of air coming into the cylinder is not enough to fulfill the compressing rate of the pistons.
So, the modification of the ECU leads to be the best modification system because it can be done easily by connecting the OBDII port to the tuning company`s computer and change the way fuel and air is injected to each of the chambers of the engine, without removing or installing any mechanical system.
7.2. Advantages of the modifications
The Advantages of the three modifications done in this project to a turbocharged engine, are mainly the way it power output is developed, and how the torque graph ins increased through the rev range, as it can be seen on the graph 5, the power is considerably increased from the stock configuration to the admission stage, to the exhaust stage and to the ECU stage.
The power curve its affected by the type of mixture inside the combustion chamber and how the exhaust gases are expelled from the cylinder; For the last configuration, the revolutions are limited to 6000 RPM range because at this point all the pressure od the turbo is used and doesn't have more air to blow in.
Graph 5. Power increase through the modifications 0
50 100 150 200 250
2200 2500 2750 3000 3250 3500 3800 4000 4250 4500 4750 5000 5250 5500 5750 6000 6250 6500 RPM
Power increase Graph
Stock [Hp] Admission [Hp]
Exhaust [Hp] ECU [Hp]
Graph 6. Torque increase through modifications
As shown in the graph 6 is a great advantage that the amount of torque delivered by the engine was increased on a great percentage, thanks to the way engine behave witch each modification, but it is important to show how close each of this curves are between 2000 and 3000 [RPM], which means that the development of the maximum torque is reached earlier for each modification, this means, that torque comes to the vehicle sooner than you would expect.
Another advantage of this modifications are the type of vehicles that the engine can out run, taking into account the money spent on the vehicle and modifications, having a 31,9 % of the power increasing means that the power is now equivalent to cars worth double or even triple than the Volkswagen Jetta, for example, with this configurations, new contenders at the racetrack are the new Audi A3, the BMW 1 series and 3 series, and even Chevrolet Camaro from 2000, which creates for sure a satisfaction feeling.
0 50 100 150 200 250 300 350
2200 2500 2750 3000 3250 3500 3800 4000 4250 4500 4750 5000 5250 5500 5750 6000 6250 6500 RPM
Torque increase Graph
ECU [Nm]
Exhaust [Nm] Admission [Nm] Stock [Nm]
7.3. Disadvantages of the modifications
The disadvantages of these modifications are mainly three, the cold air intake filter to close to the floor, the heat at the turbocharger and the fuel consumption rates. These are some of the reasons, people stay with a stock vehicle instead of increasing it`s performance.
7.3.1. Low cold air intake
A low cold air intake can some times be the cause of several damages to an internal combustion engine, for example, on a rainy track day, its very probable that this filter absorbs some of the water of the floor, meaning that this water will come through the inlet, intake and directly to the cylinders, and as it is known, the water is uncompressible, which means that the pistons could brake or even the engine walls can collapse.
7.3.2. Extreme Temperatures
Knowing how the antilag of the Etuners reprogram system works, and that the exhaust system can take all the combustion of the cylinders, temperatures can go un to 1200ºC creating a thermal deformations of the turbo spools creating several damages to the engine an the exhaust pipes.
7.3.3. Fuel Consumption
Fuel consumption is one of the main disadvantages, for being able to reach high amounts of power and torque, the mixture inside the cylinders need to me rich, and using more fuel is the best option, but sometimes, people is not attracted by this consequence so they stay with a stock engine.
7.4. Other Approaches
Taking into account that all the mechanical modifications are done to the vehicle, there are other ways to have a better performance on track, or competition. There are three ways to increase the performance, the fuel used, the weight of the vehicle and the tires used.
The fuel is usually bought on a petrol station, but there are several brands that are dedicated to produce fuels with a higher octane number such as Sunoco, there is also another fuel called Ethanol, which is a mixture between normal fuel and ethylic alcohol, and is represented with a letter and a Number, for example the E50, is ethanol with 50% concentration of ethylic alcohol.
The weight of the vehicle can be reduced by removing all the seat and the spare tire, although this doesn’t seem like a lot, it can be represented on two or even three tenth´s of a second on the quarter mile, crucial for a final drag race.
The tires are one of the most important part of a racing vehicle, because are in charge of setting the power down to the tack, For a quarter mile, soft slick´s tires are the best option to chose, being able to win five or even six tenth of a second.
These modifications were also proved on the tested vehicle, but with street tires, in which it reached a top speed of 171 [Km/h] and a quarter mile time of 15,26 [s].
8. Summary
So, a summary to this projects results and process is showed on the graph 7, which shows the specific value reached for each stage of the project, were it can be seen an improvement from modification to modification.
Graph 7. Maximum value for each modification
Taking into account all the results on the previous chapters, the intention of this one is to show the explicit values of the project and get to some conclusions of the same, just as shown in the graph 8, that shows the revolution at which the maximum power and torque is reached, a very important value that shows the relation between the transmission and the engine.
The maximum power is reached earlier on each modification, starting with the stock configuration that reaches is higher power at 6000 [RPM] in comparison to the all modified system which reaches maximum power at 5410 [RPM]. On the other side the torque is reached earlier until the ECU modification because at the last configuration, the curve can reach higher values but it takes the engine a bit longer to make them.
159,7 185,1 204,7
234,7 267,132 284,76 302,388
332,22
0 100 200 300 400
Stock Admission Exhaust ECU
Maximum Value for each
modiRication
Graph 8. Maximum revolution value for each modification
So, it can be concluded that the power an torque of a turbocharged internal combustion engine, can always be modified, it just depends on the owner of the vehicle, how far is he able to go and if his economic system can hold it, as it was mentioned at the very beginning, automotive industry is one of the most expensive ones.
But this is only a good reason to so experiments and get dirty underneath the engine, this project was developed with a very positive intention, in which all modifications coasted around 1000 $ dollars.
Finally, this project fulfilled each one of its objectives were more than 75 horsepower were increased to the turbocharged Volkswagen and more than 65 Newton meters by the modifications of the admission, exhaust and ECU mechanical systems. On he other side specific graphs were obtained to determine the unique engine behavior at each modification level. Also the project was done with less than 5000 $, saving money to the sponsors up to a 4000 $.
6000
5125 6150 5410 3850 3700 3650 4420
0 2000 4000 6000 8000
Stock Admission Exhaust ECU
RPM
RPM at which maximum value
is reached
9. Suggestions
9.1. Technical suggestions
The technical suggestions are based on the experiences at the installation of each modification system. Were it can be helpful if some one tries to replicate the work done on this project.
For the Admission system, its important to start from the inlet installation, because its, closer to the turbo, wait until the engine temperature is not harmful to the has and disconnect all the hoses that get to the inlet, paying close attention to he hoses order. For the cold air intake it’s as hard as pulling of the battery, connect the filter and install again the battery. For the Front Mounted intercooler is necessary to do a very careful calculus of the pipeline that connects it to the engine.
For the exhaust System, some welding and materials skills will be needed, but nothing very out of the reach of a normal workshop, make sure to measure all the angles needed for each curve of the pipeline, and to set at the center of the exit the exhaust muffler.
9.2. Competition Suggestions
The divers skills are needed to a correct measurement of the specific times for each modification stage, practice is the only one that can help to get a very accurate result. First and second gear are the most important gears at a quarter mile race, so make sure to slip a little bit the clutch just to know were the traction of the wheels is starting to let it go completely.
10. Future Work
The future work of this project, can involve the answer of the question asked in the section 6.1.2. Why do the main companies produce their vehicle with that many limitations, if the engine can hold more torque and power?. It is certain that factories around the world produce their vehicles to last through the years, but the limitations imposed to each model seem to be impose to create a different range of vehicles with the same components and being able to charge more money to their buyers for a car less limited.
On the other side, future work can involve further and complex modifications to an internal combustion engine, such as the installation of a bigger turbo, a different transmission that can hold the power out put of the engine and it can be took as far as the investigator is able.
Some important approaches in the automotive industry include the vehicle dynamics in which the movement of the vehicle can be analyzed. Also every component of the vehicle can be studied in depth such as the suspension, the tires, the transmission and the engine.
11. References
pope, j. (2009). analysis of a turbocharger system for a diesel engine. thesis, rensselaer polytechnic institute, mechanical engineering, connecticut.
ademola, a. (2009). a study of the local design modifications on imported heavy vehicles in ghana. thesis, college of engineering, faculty of mechanical and agric engineering, ghana.
casal, i. g. (2014). aerodynamic analysis and improvement of a roof box car. thesis, cracow university of technology, mechanical faculty, krakow.
peciura, j. (2014). swirling airflow influence on turbocharger compressor performance. thesis, chalmers university of technology, department of applied mechanics, goteborg.
kristoffersson, i. (2006). model predictive control of a turbocharged engine. thesis, electrical engineering, stockholm.
snout, a. (s.f.). recuperado el 04 de 04 de 2016, de http://www.autosnout.com/quarter-mile-car-list.php
arcoumanis, d. (12 de 02 de 2011). thermopedia. recuperado el 13 de 02 de 2016, de internal combustion engine: http://www.thermopedia.com/content/880/
cengel, y. a. termodinamica (septima ed.). mc graw hill.
bosch. (2015). bosch auto parts. recuperado el 24 de 02 de 2016, de bosch: https://www.boschautoparts.com/en/
borwarner. (s.f.). borewarner. recuperado el 12 de 04 de 2016, de
http://www.borgwarner.com/en/_layouts/mobile/mblwiki.aspx?url=/en/mobilepages/home. aspx&mobile=1
luis felipe navarro uniandes. (24 de 03 de 2016). obtenido de youtube: https://www.youtube.com/channel/ucxxut9ud_clgfewpnu3groa
