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Turbocharger

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Turbocharger

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GENERAL INFO

A turbocharger is an exhaust gas driven compressor used in internal-combustion engines to increase the power output of the engine by increasing the mass of oxygen entering the engine. A key advantage of turbochargers is that they offer a considerable increase in engine power with only a slight increase in weight.[1]
In internal combustion engines a turbocharger is a turbine driven forced induction compressor powered by pressure from the engine's exhaust gas. This is in contrast to a supercharger, which is mechanically driven by the engine's crankshaft via a belt.[2]


KEY TOPICS

Section Contents:
  • Turbochargers start producing boost only above a certain rpm (depending on the size of the turbo) because they are powered by the movement of exhaust gases; without an appropriate exhaust gas velocity, they logically cannot force air into the engine.(More...)

  • Turbocharger kits, supercharger kits, blow-off valves, intercoolers, boost controllers, turbo timers, wastegates, and more.(More...)





Turbochargers start producing boost only above a certain rpm (depending on the size of the turbo) because they are powered by the movement of exhaust gases; without an appropriate exhaust gas velocity, they logically cannot force air into the engine. [2] Turbocharger starts producing boost only above a certain rpm due to a lack of exhaust gas volume to overcome inertia of rest of turbo propeller. This results in a rapid and nonlinear rise in torque, and will reduce the usable power band of the engine.[2] Using turbochargers to gain performance without a large gain in weight was very appealing to the Japanese factories in the 1980s. The first example of a turbocharged bike is the 1978 Kawasaki Z1R TC. It used a Rayjay ATP turbo kit to build 5lb (2.3kg) of boost, bringing power up from ~90 hp to ~105 hp. It was only marginally faster than the standard model (11 lb and 145hp (108kW) with a modified wastegate).[2] Some car makers use water cooled turbochargers for added bearing life. This can also account for why many tuners upgrade their standard journal bearing turbos (such as a T25) which use a 270 degree thrust bearing and a brass journal bearing which has only 3 oil passages, to a 360 degree bearing which has a beefier thrust bearing and washer having 6 oil passages to enable better flow, response and cooling efficiency.[2]

Turbochargers with foil bearings are in development which eliminates the need for bearing cooling or oil delivery systems, thereby eliminating the most common cause of failure, while also significantly reducing turbo lag.[2] Variable-nozzle turbochargers (discussed above) eliminate lag. Another common method of equalizing turbo lag is to have the turbine wheel "clipped", or to reduce the surface area of the turbine wheel's rotating blades.[2] In internal combustion engines a turbocharger is a turbine driven forced induction compressor powered by pressure from the engine's exhaust gas. This is in contrast to a supercharger, which is mechanically driven by the engine's crankshaft via a belt.[2]

The demands of the war led to constant advances in turbocharger technology, particularly in the area of materials. This area of study eventually crossed over in to the development of early gas turbine engines. Those early turbine engines were little more than a very large turbocharger with the compressor and turbine connected by a number of combustion chambers.[2] Often the same basic turbocharger assembly will be available from the manufacturer with multiple AR choices for the turbine housing and sometimes the compressor cover as well. This allows the designer of the engine system to tailor the compromises between performance, response, and efficiency to application or preference. Both housings resemble snail shells, and thus turbochargers are sometimes referred to in slang as snails.[2] The turbocharger has four main components. The turbine and impeller /compressor wheels are each contained within their own folded conical housing on opposite sides of the third component, the center housing/hub rotating assembly (CHRA). The housings fitted around the compressor impeller and turbine collect and direct the gas flow through the wheels as they spin.[2] A turbocharger consists of a turbine and a compressor linked by a shared axle.[2] Although adding a turbocharger itself does not save fuel, it will allow a vehicle to use a smaller engine while achieving power levels of a much larger engine, while attaining near normal fuel economy while off boost/cruising.[2] To minimise the effects of turbo-lag some high end vehicles use two turbochargers in series, one is somewhat smaller and spins up more quickly and thus cuts in at relatively low engine speed and improves low end torque whereas the other cuts in at high engine speeds. This creates a smoother and higher torque curve and thus makes the vehicle faster and easier to control.[2] Using a small turbocharger will give quick response and low lag at low to mid RPMs, but can choke the engine on the exhaust side and generate huge amounts of pumping-related heat on the intake side as RPMs rise.[2] Conversely on light loads or at low RPM a turbocharger supplies less boost and the engine is less efficient than a supercharged engine.[2] Because boost is related to engine load, the turbocharger only runs at full capacity when the engine is under load.[2] Newer turbocharger and engine developments have caused boost thresholds to steadily decline to where day-to-day use feels perfectly natural.[2] Since a turbocharger increases the specific horsepower output of an engine, the engine will also produce increased amounts of heat. This can sometimes be a problem when fitting a turbocharger to a motor that was not designed to cope with high heat loads. It is another form of cooling that has the largest impact on fuel efficiency: charge cooling.[2] Superchargers and turbochargers use output energy from an engine to achieve a net gain, which must be provided from some of the engine's total output.[2] Turbochargers are used in reciprocating aircraft engines which are designed for high altitude use.[2] Turbochargers were first used in production aircraft engines in the 1930s before World War II.[2]

If a turbocharger that is too large is used it reduces throttle response as it builds up boost slowly. Doing this may result in more peak power.[2] Gasoline engines often require extensive modification for turbocharging. Diesel engines have a narrower band of engine speeds at which they operate, thus making the operating characteristics of the turbocharger over that "rev range" less of a compromise than on a gasoline-powered engine.[2]

Complexity. Further to cost, turbochargers require numerous additional systems if they are not to damage an engine.[2] The first production turbocharged automobile engines came from General Motors in 1962. The A-body Oldsmobile Cutlass Jetfire and Chevrolet Corvair Monza Spyder were both fitted with turbochargers.[2] A pair of turbochargers mounted to an Inline 6 engine ( 2JZ-GTE from a MkIV Toyota Supra ) in a dragster.[2] The turbocharger was invented by Swiss engineer Alfred B"chi. His patent for a turbo charger was applied for use in 1905.[2] Race cars often utilize an Anti-Lag System to completely eliminate lag at the cost of reduced turbocharger life. On modern diesel engines, this problem is virtually eliminated by utilizing a variable geometry turbocharger.[2] Maserati in 1980 was the first to introduce twin or bi-turbo Maserati Biturbo. Renault however gave another step and installed a turbocharger to the smallest and lightest car they had, the R5, making it the first Supermini automobile with a turbocharger in year 1980. This gave the car about 160bhp (120kW) in street form and up to 300+ in race setup, which was extraordinary output for a 1400 cc motor.[2] In either case, an automatic or manually-controlled wastegate is used to vary the turbocharger output according to operating conditions.[2] Due to a lack of sufficient materials as well as funding, initial progress was slow. Turbochargers were used extensively in military aircraft during World War II to enable them to fly very fast at very high altitudes.[2]

One way to take advantage of the different operating regimes of the two types of supercharger is sequential turbocharging, which uses a small turbocharger at low RPMs and a larger one at high RPMs.[2] Electrical boosting ("E-boosting") is a new technology under development; it uses a high speed electrical motor to drive the turbocharger to speed before exhaust gases are available, e.g. from a stop-light.[2]

In the late 1970s, Ford and GM looked to the turbocharger to gain power, without sacrificing fuel consumption, during not only the emissions crunch of the federal government but also a gas shortage.[2] As turbocharger technology improved, it became possible to produce turbocharged engines with a smoother, more predictable but just as effective power delivery.[2]

One of the first applications of a turbocharger to a non-Diesel engine came when General Electric engineer Sanford Moss attached a turbo to a V12 Liberty aircraft engine.[2] Boost refers to the increase in manifold pressure that is generated by the turbocharger in the intake path or specifically intake manifold that exceeds normal atmospheric pressure. This is also the level of boost as shown on a pressure gauge, usually in bar, psi or possibly kPa. This is representative of the extra air pressure that is achieved over what would be achieved without the forced induction.[2] Because the turbocharger increases the pressure at the point where air is entering the cylinder, and the amount of air brought into the cylinder is largely a function of time and pressure difference, more air will be forced in as the inlet manifold pressure increases.[2]

Turbochargers also provide more direct fuel savings when compared to a supercharger.[2] Lastly, the efficiency of the turbocharger itself can have an impact on fuel efficiency.[2]

Heavily modifying OEM turbocharger systems also require extensive upgrades that in most cases requires most (if not all) of the original components to be replaced.[2] The oil is usually taken from the engine-oil circuit. Some turbochargers use incredibly precise ball bearings that offer less friction than a fluid bearing but these are also suspended in fluid-dampened cavities.[2] Diesel ships and locomotives with turbochargers began appearing in the 1920s.[2]

To manage the upper-deck air pressure, the turbocharger's exhaust gas flow is regulated with a wastegate that bypasses excess exhaust gas entering the turbocharger's turbine. This regulates the rotational speed of the turbine and the output of the compressor.[2] As the turbocharger's output flow volume exceeds the engine's volumetric flow, air pressure in the intake system begins to build, often called boost.[2]

A turbocharged engine produces more power overall than the same engine without the charging. This can significantly improve the power-to-weight ratio for the engine (see How Horsepower Works How Horsepower Works for details). In order to achieve this boost, the turbocharger uses the exhaust flow from the engine to spin a turbine, which in turn spins an air pump.[3] The turbine in the turbocharger spins at speeds of up to 150,000 rotations per minute (rpm) -- that's about 30 times faster than most car engines can go.[3] In this article, we'll learn how a turbocharger increases the power output of an engine while surviving extreme operating conditions. We'll also learn how wastegates, ceramic turbine blades and ball bearings ball bearings help turbochargers do their job even better.[3] Turbochargers are a type of forced induction system. They compress the air flowing into the engine (see How Car Engines Work How Car Engines Work for a description of airflow in a normal engine).[3] In the Engine Performance section, learn about horsepower, carburetors, the difference between turbochargers and superchargers and even how nitrous oxide boosts engine performance.[3] The typical boost provided by a turbocharger is 6 to 8 pounds per square inch (psi).[3]

This is a high quality cast iron manifold for all 12V VR6 applications, that allows mounting a standard T4 flange (tangential housing) turbocharger.[3] When people talk about race cars race cars or high-performance sports cars, the topic of turbochargers usually comes up.[3]

With air being pumped into the cylinders under pressure by the turbocharger, and then being further compressed by the piston (see How Car Engines Work How Car Engines Work for a demonstration), there is more danger of knock knock.[4] There are many tradeoffs involved in designing a turbocharger for an engine. In the next section, we'll look at some of these compromises and see how they affect performance.[4] In order to handle speeds of up to 150,000 rpm, the turbine shaft has to be supported very carefully. Most bearings would explode at speeds like this, so most turbochargers use a fluid bearing. This type of bearing supports the shaft on a thin layer of oil that is constantly pumped around the shaft. This serves two purposes: It cools the shaft and some of the other turbocharger parts, and it allows the shaft to spin without much friction.[4] Cars with turbochargers often need to run on higher octane octane fuel to avoid knock.[4]

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Turbocharger kits, supercharger kits, blow-off valves, intercoolers, boost controllers, turbo timers, wastegates, and more. [5] Got a question about turbocharger kits? Get answers to some of the more common ones.[5]

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IN-DEPTH

Section Contents:
  • " Satya, Traffic Turbocharger Traffic Turbocharger is FANTASTIC!(More...)

  • Melett supplies replacement turbocharger repair kits and parts to the independent aftermarket to allow reconditioning, remanufacturing and repair of turbo models originally manufactured by Garrett, Holset (Cummins Turbo Technologies), Borg Warner (Schwitzer & 3K), MHI (Mitsubishi), Komatsu, Toyota, IHI & Hitachi.(More...)

  • I've looked at a number of other consumer-oriented turbocharger books and they have all been poorly written, not well illustrated and out of date.(More...)



" Satya, Traffic Turbocharger Traffic Turbocharger is FANTASTIC! It really is easy to use and understand. Anyone looking to get better rankings in the top search engines needs to check this software out! Any webmasters primary goal, should be to increase targeted traffic to their sites and apply several income paths along the way. [6] In fact you can also use your own templates with the Traffic Turbocharger tags added in.[6]

Because Traffic Turbocharger not only creates pages that attract search engines like bees to a honey-pot, but also ENSURES your pages are ALWAYS attractive to your human visitors.[6] Every time you run the Traffic Turbocharger script on your server, not only can you create a website with THOUSANDS of CONSTANTLY SELF UPDATING pages that consistently rank high on search engines, but also ones that will earn YOU DEFINITE income from 5 different sources.[6]

That's not all, because along with your copy of Traffic TurboCharger you'll also receive these amazing bonuses.[6]

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Melett supplies replacement turbocharger repair kits and parts to the independent aftermarket to allow reconditioning, remanufacturing and repair of turbo models originally manufactured by Garrett, Holset (Cummins Turbo Technologies), Borg Warner (Schwitzer & 3K), MHI (Mitsubishi), Komatsu, Toyota, IHI & Hitachi. [7] APS Turbo Kits APS have over twenty years experience in designing and manufacturing turbocharger and intercooler systems combined with an extensive background in EFI engine management systems for select 4X4 and performance passenger cars.[1] With a GReddy bolt-on turbocharger kit, you can obtain instant horsepower gain with less time and money and still have the potential for upgrading. Since they are based completely on stock engines, these kits come with all the necessary basics, including fuel enrichment. If competition use is your goal, there are many GReddy upgrades to boost the power output even further, such as: intercoolers, blow-off valves, fuel management and boost controllers.[1] Conversely on light loads or at low rpm a turbocharger supplies less boost and the engine is more efficient than a supercharged engine.[1] Turbochargers spin between 80,000 and 150,000 rpm depending on size, weight of the rotating parts, boost pressure developed and compressor design. Such high rotation speeds would cause problems for standard ball bearings leading to failure so most turbo-chargers use fluid bearings. These feature a flowing layer of oil that suspends and cools the moving parts.[1] A turbocharger is an exhaust gas driven compressor used in internal-combustion engines to increase the power output of the engine by increasing the mass of oxygen entering the engine. A key advantage of turbochargers is that they offer a considerable increase in engine power with only a slight increase in weight.[1] A turbocharger also has a turbine that powers the compressor using wasted energy from the exhaust gases.[1] The turbocharger was invented by Swiss engineer, Alfred Buchi, who had been working on steam turbines. His patent for the internal combustion turbocharger was applied for in 1905.[1]

HKS Turbocharger Kits Every HKS Turbo, Turbo Kit, and other turbo related components, from the HKS sport & GT turbos to the HKS cast iron turbo manifolds & Turbo Set-Up Kits, are all race proven and engineered with the highest standards in performance, function & reliability.[1] Greddy Turbocharger Kits GReddy Bolt-On Turbocharger Kits are designed specifically for driveability and reliability, as well as performance.[1]

To manager air pressure, the turbocharger's exhaust gas flow is regulated with a wastegate that bypasses excess exhaust gas entering the turbocharger's turbine. This regulates the rotational speed of the turbine and the output of the compressor.[1]

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I've looked at a number of other consumer-oriented turbocharger books and they have all been poorly written, not well illustrated and out of date. This book is perfect - it mixes a good introduction to four stroke engines, theoretical and practical aspects of turbocharging and several interesting project cars. [8] This is a very easy to understand book. suited for the enthusiast not an engineer. The author takes the reedier through all the aspects of turbocharging, like selecting a turbocharger, types of intercoolers, exhaust manifold design, boost controllers, and so on. Seldom, theory is discussed in this book except in chapters 1 and 16. Be aware, this author for some reason wrote misleading sentences in this book that contain his opinion, not facts! Over all very good book.[8]

The power-enhancing capability of the turbocharger has been most thoroughly demonstrated by the Grand Prix racing cars of the 1977 to 1988 era of Formula 1.[8]

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