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lOOK, THIS IS A PROJECT I DID TO GRADUATE HIGH SCHOOL. WITH EVERYTHING, IT IS IN ALL 20 PAGES LONG. THIS IS HALF OF IT. IT IS ABOUT TURBOCHARGING, AND I HAVE ACUTALLY TAKING IT UPON MY SELF TO TURBO MY 1991 626 LX TO BACK ALL THIS INFO UP. THE ONLY THING KEEPING ME FROM COMPLETEING THAT GOAL IS MOENY. THIS IS ALL THE RESEARCH I HAVE DONE, AND IT REALLY IS RELAIBLE AND IN DEPTH.. I CAN GO INTO MORE DEPTH, BUT THEN I WORK HAVE TO WRITE A BOOK. THERE ARE BOOKS OUT THERE ALREADY, BUT THIS I A GOOD READ BASED ON A TURBO PROJECT ON OUR CARS.


Rob Hays
Senior Research Project
3/17/07
AP English
Mr. Allen
Turbocharging

ENGINE OVERVIEW AND HISTORY:

In 1867, at age 34, Nikolaus August Otto, an engineer from Germany, patented the first four-cycle internal combustion engine. (SIUC) That engine, and its design has not changed much since its original production in the late 1800’s, and is the main force that supports the fleets of transportation to this day. Otto has given us the blue print of a basic machine that works. However, in terms of efficiency, which is the evil of all machines, Otto’s original design leaves room for vast improvements that the auto industry has been trying to exploit for the last one hundred years. Turbocharging is a direct result of the industry’s lust for power and economy from a now basic and obsolete blue print to engine design.
FOUR STOKE ENGINE BASICS:

An internal combustion engine s we have known it has four stokes and is basically a big air pump. Understanding how this operation works, will allow you to understand the whole application of turbocharging as a whole system because the turbo is going to maximize the engines ability to suck in more air. The first stoke, is the Intake stoke where the piston starts at top dead center (TDC) of the piston bore, and is pulled downward. While this is happening, air is being drawn into the cylinder because of a vacuum that is created by the motion of the piston going down, and fuel is injected into the cylinder by the fuel injectors. The second stoke then begins when the cylinder reaches bottom dead center (BDC) and begins its way back up the cylinder. At this time, the intake and exhaust valves at shut and make a complete seal. This allows the second stoke, or compression stroke to compress the air fuel mixture so that is become more dense in a smaller, more explosive volume. When the piston fully compresses the air-fuel mixture, and reaches (TDC), the spark plugs ignite causing a force around 350-700 pounds per square inch down on the piston from the exploding expanding gases. This power stoke produces such Huge amount of energy with a downward force on the piston, that if it was not connected to the crankshaft, the piston would be buried into the ground. (Bouffard) This stoke is where all the torque and horsepower comes from, and this is where “gear heads” focus a lot of their studies on, cause everyone wants more power to go faster! The finial stoke in this series is the exhaust stoke where the exhaust valve opens and the pistons continues its path back up to (TDC) and pushes all the exspent gases out and into the exhaust system.
TURBO HISTORY:

The turbocharger is a device that has quite a history. It has been around since the early 1900’s, and was used largely in aircraft during WW1. It is a very precise piece of equipment that acts as an air pump.


TURBO TEST FROM HOTROD MAGIZNE

Turbocharging is known as the most efficient overall form of forced induction that man knows. In an actual test, from HOTROD Magazine, three forms o forced induction were put to the test on a stroker 5.0L ford engine. A Paxton Navi 1200 Centrifugal Blower (supercharger), Holley 174ci Blower, and a HP Performance Turbo, were all applied to the same engine. In terms of horsepower and torque, the Holley 174ci Blower came in last with 535hp at 6000 rpm and 513 ft-lbs of torque at 4600rpm. Even though it only produced 8 lbs of boost will the others produced 9 lbs, the gain of one extras pound of boost would only be about 20 hp and ft-lbs of torque. Now, the while the Paxton Supercharger produced slightly bigger numbers (617 hp at 6000rpm and 561 ft-lbs of torque at 52000 rpm) than the HP Turbo (600hp at 6000rpm and 617 ft-lbs of torque at 4200rpm) the overall performance goes to the Turbo because its torque and power peaks quicker and then drifts down a little while the supercharger gains its peaks gradually throughout the rpm range. The graphs do show that the Paxton’s hp peaks higher than the Turbo, but only after 5600 rpm. The area under the graphs shows clearly that the Turbo produces more overall power throughout the whole power curve. (Holdener) The Turbocharger is this efficient because it is not powered by a belt that is driven by the crankshaft. A Turbocharger is propelled by the wasted energy of the exhaust. Because heat is energy, and one third of that energy is absorbed in the cooling system to keep the engine in operating temperature, another third is used to actually propel the engine forward by turning the crankshaft, and the last third is just forced through the exhaust system. It is this one third of energy that the turbo uses to provide useful energy. A turbocharger changes wasted energy into usefully energy, therefore making the whole system more efficient.
POWER EQUATIONS... VERY HELPFUL!

Gaining power is a not that complicated to calculate in theory on paper. Using three very simple equations, you can calculate Theoretical HP, Torque and Pressure curves. The first equation is Power=PxLxAxN.
L is the stroke length.
A is the area of the piston.
N is the rpm divided by two, times the number of pistons.
P represents the pressure that is pushing the piston down the bore.
In addition, parts of this equation equal certain values.
PA=Force
PAL=Torque
Torque X rpm= Power
If you can maximize the pressure on the piston during its power stoke, then you can make more power than having and engine with more displacement. (Bell)
The second equation is HP= Torque X RPM/ 5252.
HP x 5252= Torque X RPM
HP x 5252= Power
If you know the torque or horse power at a given rpm, you can find the opposite with this equation. In order to get these graphs, you must combine the first two equations together, and solve for the unknown you want. Now, lets put this into perspective (go to sheet labeled Equations and graphs.)
PARTS OF A TURBO AND HOW THEY WORK:

The turbo is made of three main parts, each having its own specific job that keeps the turbo functioning efficiently as possible. The turbine, commonly known as the hot side of the turbo, is put in the path of the exhaust gasses exiting the block. This is done by customizing an exhaust manifold that will allow a place to bolt the turbine side of the turbo. Now, when the engine is running, the force of the gasses will run through the fins of turbine, and cause the turbo to spool up to speeds of 100,000-140,000 rotations per minute. (RPM) Now, because this side of the turbo is the hot side, it experiences huge fluxes in temperature ranging from ambient temperature in cold New England nights to full operational temperature that can exceed 1500 degrees Fahrenheit. Due to these huge extremes, the turbine must be able to cope with both, and the engineering shows it. Turbines housings are usually cast Iron. However, with resent developments, ceramic turbines, which are lighter and spool faster than heavy iron turbines, are being used in high power applications. Turbine size, fin size changes, and fin direction different between each application, each having its own characteristics.
 

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TURBO COOLING:

The turbo spins at speeds that are 10 to 12 times faster than an engine. The reason that the turbine shaft does not just shatter into a million pieces is the center piece that holds the whole setup together. The mid-section lubricates and cools the rod so that it will stay at an operating temperature that will not deteriorate the turbo and keep it working for many boosted mile. Most turbos are just oiled cooled, where oil is run through the mid-section and drained out to both lube and drain heat from the rod. Factory OEM turbos sometimes are made with an oil and water cooled rod. This dramatically increases heat loss which is good for the turbos sake. This is workable because engineers were able to effectively design a water jacket, like those around the cylinders in the engine block, and enables coolant to run though and further cool the rod. However, because most aftermarket turbos are not water-cooled and just oil cooled, you can not neglect coolant from a turbo that was designed to be water-cooled as well
COMPRESSOR:

The compressor side, or cold side of the turbo, is the air pump. It is powered by the turbine, and spun because of the turbine shaft that connects the two together. The compressor is what creates all the boost, and this is what the turbo enthusiasts wants to hone to create street machines with huge power with limited displacement. Ideally, it would be splendid if you could just add more air into the combustion chamber. But, it just doesn’t work like that. Everything has its draw backs, and air has its when being compressed. Let’s move away from the compressor talk for a minute and talk about atoms that is taught in chemistry. As a law of thermodynamics, air raises in temperature dramatically as it is compress, and the more it is compressed, or more boost you add, the hotter the air will become as it enters the combustion chamber. It is known that as an atom is heated, the more excited it becomes. This in turn causes the air entering the throttle body to be less dense. So even with the boost level higher than atmospheric pressure, 14.7 PSI, the amount of air able to be forced into the chamber is limited. The idea of forced induction is to cram as much air into the combustion chamber as possible, so the air must in some way lose its charged temperature after it is compressed by the turbo.
ECU:

Even with the fact that a turbo is a power adder in any correct application; the turbo itself must be run within certain parameters and has to be supported by a number of devices. First off, the ECU, or Electronic Control Unit, is probably the most important device to whole system. The ECU is the brain of the engine, in that it reads a whole bunch of different input devices that are set to measure things such as boost, oil pressure, oxygen content, water temperature, air temperature ect. It then takes these readings and provides the correct fuel map and the amount of fuel to the injector to inject so that the engine may run correctly. With a turbocharger, the fuel/air ratios not only change throughout the whole rpm range, but also during different boost situations. This is because the more air that is forced into the cylinder, the more fuel must also be injected into the cylinder to compensate and meet the standard 12:1 air to fuel ratio. If you run to rich, you will damage the catalytic converter and have bad emissions because all the fuel will not burn fully. Or, even worse, if your run your engine lean on run, you increase your chances for detonation, knock, and can damage your engine quickly. With electronic fuel ignition, the ECU controls the injection of the fuel, as well as ignition. This is because the ignition timing, like the fuel injection, changes during different boost pressures and RPMs. The ECU has the job of ignition advance and retard during boost and non-boost situations.
EXHAUST:

On a normally aspirated engine, the stock exhaust system of any OEM vehicle is very restrictive, and a good start to change to get a quick and easy jump of at least 20 extra horsepower. The reason that you would switch out the stock exhaust system, for a more free-flow system with lower back pressure, is because it allows the engine to breath better. When the engine can breathe, no exhaust gases will have a chance to be sucked back into the cylinders, robbing the engine of potential energy. However, with a turbocharged vehicle, you must have a little backpressure or resistance in the exhaust system so that the turbine is not constantly spinning at full spool. In other words, on a stock system, you should add a less restrictive exhaust system to the vehicle, but that does not mean you put four inch exhaust pipes after the turbocharger. Bigger is not better in this case, because the bigger the pipe, the faster the exhaust gas will cool. In this case, this is bad because the gas will not flow as fast, and because of the larger pipe, the gas does not travel at a slower velocity, further slowing its exit. A larger pipe that provides lower restriction, and is small enough to keep the velocity of the exiting gas up is the desirable design for a turbo exhaust system. Mandrel bends are also desired when putting the system in.
INTAKE:

Just like the exhaust flow, the intake flow must be just like this. The intake piping must be non-restrictive with the use of mandrel bends. Velocity is also a big part in how the much air can enter the cylinder. Just like the exhaust, the bigger the air pipe is not always better, because the intake air has the same properties the exhaust gas has. Air intake pipes are commonly made of aluminum or mild steel pipe because of there lightness and ability to be mandrel bent in anyway. Routing techniques start at the air filter and end at the throttle body. It is convenient for the system to be as short as possible, but do not distort bends or forget devices to reach this objective in compromising the correct application of the whole system. To start at the air filter, it must be located where it a get cool, free flowing fresh air. The piping then will be directed to the Compressor inlet where the air is then compressed and charged. The air will now exit the compressor housing under pressure and is piped into the intercooler. The efficiency of the intercooler is important to the max output of the system. You do not want an intercooler that will restrict the air flow more than 2 PSI drop at max boost. From the intercooler outlet, the piping should continue right to the throttle body.
 

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COOLING:

Now, because the engine is going to be making more power in a turbocharged system, it is going to make more heat. It is advisable to make sure your stock cooling system will be able to keep up with the extra heat load. If not, then you must upgrade so you don’t overheat, or otherwise put your engine in a melt down situation.
Oil coolers are also another good way to keep your engine cooler, and to reduce wear on bearings. Oil coolers are commonly found on heavy duty trucks, but are a great accessory to a turbo system. The turbo, being cooled by the oil in entire lubrication system, causes the oil to be hotter than usual. Oil will break down at a certain temperature and lose its lubrication properties and viscosity. The oil cooler is just like a radiator, that the oil runs through the passages and is cooled by the air rushing through it. Mount this cooler respectively to free flowing air that is cooler than the oil itself. An oil filter relocation kit may be required to purchase as well. There are also oil coolers that are cooled by the coolant system of the car. These can be mounted anywhere, because the system does not need cool air flow to cool the oil that is run through it. (Devon)
INTERCOOLER:

Another very important part of a turbo system is the intercooler. Even though, in some applications, it is not needed in low boost situations, it is a must in all boost situations higher than 7lbs. The intercooler it self is a radiator that cools the intake air temperature. There are two types, the air to air intercooler, and the air to water intercooler. To start with, the air to air intercooler is the simplest and most common type of intercooling. It is made of a core of aluminum fins that have air passages in them. With the intake air passing through these passages, and the ambient air of the environment rushing through the aluminum fins attached to these passages, the warmer intake air will transfer its heat to the cooler outside air rushing past the fins. For maximum efficency of the air to air intercooler, it must be mounted in a place where it can have the coolest and best air flow. It is commonly mounted in front of the radiator. The air to water intercooler has the same design in that the air intake air is flown through the same type of aluminum passages. However, it is cooled by a surrounding body of water. This fluid can be either circulated though the original engine cooling system, or though its own separate system. In extreme applications, such as drag racing, it is known for racers to have an air to water cooler mounted somewhere in engine compartment in a water sealed container. That container then would be filled with cold water and ice for maximum air intake cooling. This application is only practical for racing, not economic for daily driving. Overall, the air to water intercooler is more efficient than the air to air intercooler. It is in respective, more costly and much more complicated to run. If you are looking for max power, then invest in an air to water intercooler. If not, then settle for an aftermarket air to air intercooler and find or make a good place to mount it.
KNOCK SENSOR:

The knock senor is a must in any turbo application. It is the saving grace to your engine if it is not running properly. It is an electrical device that sends an output voltage back to the ECU when it senses a ping or knocks in the engine. The signal to the ECU will then conversely adjust air-fuel ratios and timing accordingly. Boost pressure will also be dropped automatically if the ECU controls the boost actuator if the knocks continue. The knock sensor is mounted in the back of the block and connected to the knock control unit and ECU.
BOOST CONTROLLER:

A boost controller is a device that controls the boost that enters the engine. This controller senses the change in pressure between the intake manifold and the compressor outlet. When the pressure in the in the intake manifold is equal to the boost pressure set on the boost controller and the compressor outlet, it then sends a vacuum reading to the waste gate. When the waste gate is open, it diverts exhaust gas around the turbine directly to the rest of the exhaust system. By doing this, the boost will level off at the wanted boost pressure and will not climb any further. There are two types of boost controllers, a manual and electronic boost controller. The manual boost controller is set to boosts by just turning an adjusting knob left of right. The farther you screw the knob into the controller, the more boost will be forced into the cylinders before the wastage is open. The electronic boost controller controls the boost the driver wants electronically. The driver can set often more than one boost pressures with this kind of boost control. Then, at the flick of a switch, under boost, the turbo will boost the amount specified at that setting. So, you could be boosting 5 lbs. while driving normally, then suddenly hit the switch and be boosting 20 lbs instantly.
WASTE GATE:

The Waste gate of the turbocharger is needed to produce level boost at a specific pressure that is less than the turbos max output. There are two different types of waste gates, an internal and external waste gate. First up, the internal waster gate is used for mass production proposes and is part of the turbine housing. The external waste gate is not part of the turbo in any way. It is piped into the exhaust system as an optional route from the exhaust manifold to the catalytic converter. When the waste gate is open, the exhaust will reroute down this passage around the turbo, directly to the catalytic converter. The external waste gate is known to be more responsive and accurate at holding boost pressure.
BLOW OFF VAVLE:

The last, and probably the coolest device in the turbo system, besides the turbo itself is the blow off valve. This is because it can make a cool pppsssshh sound. The noise is created by the rushing of charged air out off the intake system, and into the engine compartment. In any turbocharged car, you must have a blow off valve or by-pass valve. This is because if there was no way for the air to go when the throttle plates where closed, that compressed air will travel back to the compressor wheel, and cause it to slow down, or completely blow up. The blow off valve releases this pressure from the system when it senses the change in boost pressure in the intake manifold and intake pipe. A by pass valve is a stock OEM blow off valve that dumps the air from the intake pip back to the pipe before the compressor inlet instead of the atmosphere, and does not make the pppsshhhh sound.
In order to turbocharge a normally asteriated engine, the process does not just include bolting a turbocharger to the exhaust manifold, connecting the intake pipes to the throttle body and the rest of the tailpipe to the turbine side of the Turbocharger. This is not an effective way of producing any type of aftermarket performance for any type of internal combustion engine. You will only end up blowing it up, and wasting a bunch of money that could have been better spent. However, when a turbo is setup to meet thermodynamic, structural, and legal parameters, it will be one of the most effective types of aftermarket performance you could use to gain the horsepower your engine can make. When the engine, exhaust, intake, cooling, ignition, and turbocharger are all working in sync, you have a machine that is made to perform with reliability and power.


Rob Hays
AP English
3/17/07

Works cited​
Bell, Corky. Maximum Boost: designing, testing, and installing turbocharger systems.
Mass. Bentley Publishers, 1997

Bouffard, Paul. Auto teacher. Class lesson about cooling system.

Devon4x4. “Oil cooling, an overview.” 2004-2006 Devon 4x4 Ltd. 11 March. 2007< www.devon4x4.com/library/?articleid=11>

Holdener, Richard. “Battle of the Boost.” Hot Rod August 2003 p.28-34
SIUC Automotive Students and ATO Club members. “Back to the Basics: Fundamentals of the Four Stroke Internal Combustion Engine.” 2002. Southern Illinois University. 16 March. 2007<http://www.siu.edu/~autoclub/frange.html>
 

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Discussion Starter #4 (Edited)
I had a bunch of graphs that i got from all these equations on this link.. if you realy want them, just let me know,and i will just send them to you..
this is actually stuff for stock GT and N/A engines. It is not exact, but pretty damn close for my likings
these equations are very useful.. look at them!!!!

http://blog.myspace.com/index.cfm?fuseaction=blog&pop=1&indicate=1
 

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Nice read, and shows an understanding of the basic concepts. HOWEVER, turbocharging is an art. As Sick6Six always points out, compressor maps and UNDERSTANDING the engines air flow characteristics will net the greatest power, reliably. Then there's the tuning aspect.

In no way am i dissing your work, just pointing out that there is ALOT more than whats written. I shared the same enthusiasm as you when I was 17 (22 now) and my turbocharging knowledge basis is still growing. It will never stop, my friend.

Good luck with it all.

~Nick.

P.S - Blow Off Valves aren't THAT kool.......:jump:
 

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Discussion Starter #6
yea.. there definatly is a lot more to it.. and i kno that... i jsut was posting it up,cuase this is what I handed in.. it had a ten page limit and it came out 20 pages.. and like you siad.. there is a lot more to cover.. thats just basics
 

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I'm sure that took you a lot of work, but frankly it's the exact same thing that's written in Maximum Boost for the most part. For everything you've written, I've read the exact same thing somewhere else...:shrug:
 

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yes. i stated the same facts that corky bell did. thats reasearch, you only have to cited someone elses ideas or opinons abou somthing. There is no opion in this paper. its straight facts. Where I did parapharse what other people siad, i gave them credit. BUt I cant just re-invent the facts about turbocharging, i stated them how you will find them in any article or book you will read about turbocharging... thats what makes them facts, cuase they don't change. Yea... its probaly the same old stuff you veterans have known for only gods knows, but for starters, me for example, are just bown away with all this information, and actuaully seeing how it works... i didnt plagerize if thats what anyone was thinkin... the citation is there
 

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got a question for everyone... besides the bad grammar are the facts that I stated right?.. or are they worng.. cause I dont want to mislead anyone
 

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If we didn't have spell checker, that would really thin out the herd, wouldn't it? He also seems unfamiliar with sarcasm.
 

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Discussion Starter #20 (Edited)
Equations:
The first equation is Power=PxLxAxN.
L is the stroke length. (3.7in)
A is the area of the piston. (8.501 inches squared)
N is the rpm divided by two, times the number of pistons. (Number of cylinders x rpm/2)
P represents the pressure that is pushing the piston down the bore.
PA=Force
PAL=Torque
Torque X rpm= Power

HP= Torque X RPM/ 5252.
HP x 5252= Torque X RPM

http://picasaweb.google.com/Robmx1390/ALLDATA626Graphs


HP x 5252= Power

N/A- 110 HP at 4700 rpm
-130 ft-lbs at 3000rpm
GT- 145HP at 4500 rpm
-190 ft-lbs at 3500 rpm At 7lbs of boost

HP= 130 X 3000/5252 HP= 190 X 3500/5252
HP= 74.24743. HP= 126.61843
 
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