How Superchargers Work!

Supercharger Basics:

A supercharger is any device that pressurizes the air intake to above atmospheric pressure. Both superchargers and turbochargers do this. In fact, the term "turbocharger" is a shortened version of "turbo-supercharger," its official name.

A twin-screw supercharger

The difference between the two devices is their source of energy. Turbochargers are powered by the mass-flow of exhaust gases driving a turbine. Superchargers are powered mechanically by belt- or chain-drive from the engine's crankshaft. An ordinary four-stroke engine dedicates one stroke to the process of air intake. There are three steps in this process: 1-The piston moves down. 2-This creates a vacuum. 3-Air at atmospheric pressure is sucked into the combustion chamber. Once air is drawn into the engine, it must be combined with fuel to form the charge -- a packet of potential energy that can be turned into useful kinetic energy through a chemical reaction known as combustion. The spark plug initiates this chemical reaction by igniting the charge. As the fuel undergoes oxidation, a great deal of energy is released. The force of this explosion, concentrated above the cylinder head, drives the piston down and creates a reciprocating motion that is eventually transferred to the wheels. A basic engine with the addition of a supercharger. Getting more fuel into the charge would make for a more powerful explosion. But you can't simply pump more fuel into the engine because an exact amount of oxygen is required to burn a given amount of fuel. This chemically correct mixture -- 14 parts air to one part fuel -- is essential for an engine to operate efficiently. The bottom line: To put in more fuel, you have to put in more air. That's the job of the supercharger. Superchargers increase intake by compressing air above atmospheric pressure, without creating a vacuum. This forces more air into the engine, providing a "boost." With the additional air in the boost, more fuel can be added to the charge, and the power of the engine is increased. Supercharging adds an average of 46 percent more horsepower and 31 percent more torque. In high-altitude situations, where engine performance deteriorates because the air has low density and pressure, a supercharger delivers higher-pressure air to the engine so it can operate optimally. Unlike turbochargers, which use the exhaust gases created by combustion to power the compressor, superchargers draw their power directly from the crankshaft. Most are driven by an accessory belt, which wraps around a pulley that is connected to a drive gear. The drive gear, in turn, rotates the compressor gear. The rotor of the compressor can come in various designs, but its job is to draw air in, squeeze the air into a smaller space and discharge it into the intake manifold.

ProCharger DISC centrifugal supercharger

To pressurize the air, a supercharger must spin rapidly -- more rapidly than the engine itself. Making the drive gear larger than the compressor gear causes the compressor to spin faster. Superchargers can spin at speeds as high as 50,000 to 65,000 rotations per minute (RPM). A compressor spinning at 50,000 RPM translates to a boost of about six to nine pounds per square inch (psi). That's six to nine additional psi over the atmospheric pressure at a particular elevation. Atmospheric pressure at sea level is 14.7 psi, so a typical boost from a supercharger places about 50 percent more air into the engine. As the air is compressed, it gets hotter, which means that it loses its density and can not expand as much during the explosion. This means that it can't create as much power when it's ignited by the spark plug. For a supercharger to work at peak efficiency, the compressed air exiting the discharge unit must be cooled before it enters the intake manifold. The intercooler is responsible for this cooling process. Intercoolers come in two basic designs: air-to-air intercoolers and air-to-water intercoolers. Both work just like a radiator, with cooler air or water sent through a system of pipes or tubes. As the hot air exiting the supercharger encounters the cooler pipes, it also cools down. The reduction in air temperature increases the density of the air, which makes for a denser charge entering the combustion chamber.

but WHAT ABOUT NOS:

Nitrous oxide has another effect that improves performance even more. When it vaporizes, nitrous oxide provides a significant cooling effect on the intake air. When you reduce the intake air temperature, you increase the air's density, and this provides even more oxygen inside the cylinder. The only problem with nitrous oxide is that it is fairly bulky, and the engine needs a lot of it. Like any gas, it takes up a fair amount of space even when compressed into a liquid. A 5-liter engine running at 4,000 rotations per minute (rpm) consumes about 10,000 liters of air every minute (compared to about 0.2 liters of gasoline), so it would take a tremendous amount of nitrous oxide to run a car continuously. Therefore, a car normally carries only a few minutes of nitrous oxide, and the driver uses it very selectively by pushing a button.

How Turbo Chargers Work!

When people talk about race cars or high-performance sports cars, the topic of turbochargers usually comes up. Turbochargers also appear on large diesel engines. A turbo can significantly boost an engine's horsepower without significantly increasing its weight, which is the huge benefit that makes turbos so popular!

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 help turbochargers do their job even better. Turbochargers are a type of forced induction system. They compress the air flowing into the engine (see How Car Engines Work for a description of airflow in a normal engine). The advantage of compressing the air is that it lets the engine squeeze more air into a cylinder, and more air means that more fuel can be added. Therefore, you get more power from each explosion in each cylinder. 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 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. 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. And since it is hooked up to the exhaust, the temperatures in the turbine are also very high. The BasicsOne of the surest ways to get more power out of an engine is to increase the amount of air and fuel that it can burn. One way to do this is to add cylinders or make the current cylinders bigger. Sometimes these changes may not be feasible -- a turbo can be a simpler, more compact way to add power, especially for an aftermarket accessory.

Turbochargers allow an engine to burn more fuel and air by packing more into the existing cylinders. The typical boost provided by a turbocharger is 6 to 8 pounds per square inch (psi). Since normal atmospheric pressure is 14.7 psi at sea level, you can see that you are getting about 50 percent more air into the engine. Therefore, you would expect to get 50 percent more power. It's not perfectly efficient, so you might get a 30- to 40-percent improvement instead. One cause of the inefficiency comes from the fact that the power to spin the turbine is not free. Having a turbine in the exhaust flow increases the restriction in the exhaust. This means that on the exhaust stroke, the engine has to push against a higher back-pressure. This subtracts a little bit of power from the cylinders that are firing at the same time. High AltitudesA turbocharger helps at high altitudes, where the air is less dense. Normal engines will experience reduced power at high altitudes because for each stroke of the piston, the engine will get a smaller mass of air. A turbocharged engine may also have reduced power, but the reduction will be less dramatic because the thinner air is easier for the turbocharger to pump. Older cars with carburetors automatically increase the fuel rate to match the increased airflow going into the cylinders. Modern cars with fuel injection will also do this to a point. The fuel-injection system relies on oxygen sensors in the exhaust to determine if the air-to-fuel ratio is correct, so these systems will automatically increase the fuel flow if a turbo is added. If a turbocharger with too much boost is added to a fuel-injected car, the system may not provide enough fuel -- either the software programmed into the controller will not allow it, or the pump and injectors are not capable of supplying it. In this case, other modifications will have to be made to get the maximum benefit from the turbocharger. How It WorksThe turbocharger is bolted to the exhaust manifold of the engine. The exhaust from the cylinders spins the turbine, which works like a gas turbine engine. The turbine is connected by a shaft to the compressor, which is located between the air filter and the intake manifold. The compressor pressurizes the air going into the pistons.

The exhaust from the cylinders passes through the turbine blades, causing the turbine to spin. The more exhaust that goes through the blades, the faster they spin.

On the other end of the shaft that the turbine is attached to, the compressor pumps air into the cylinders. The compressor is a type of centrifugal pump -- it draws air in at the center of its blades and flings it outward as it spins. 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.

Widebody Turbo Honda S2000

Exterior: Custom widebody, 3-inches widened up front, 6-inches widened in the rear, flares added to doors, modified C-West front and rear bumpers, taillights modified, custom scoops, Imola Orange Pearl paint, graphics by Competition Grafix, APR Performance carbon fiber hood, Formula GT3 side mirrors, GT300 rear wingEngine:Garrett GT3071R turbocharger, LoveFab exhaust manifold, V-mount GReddy intercooler setup, Koyo radiator, HKS Super Sequential blow off valve, TiAL 44mm wastegate, port and polished head, 11.0:1 pistons, custom 4-inch intake system, K&N filter, STR 74mm throttle body, 3-inch downpipe, A’PEXi N1 muffler, AEM fuel pressure regulator, Precision 800cc fuel injectors, Nitrous Express system, Exedy clutchSuspension:TEIN RA coilovers, titanium front strut braceWheels / Tires:(front) 18x9-inch Volk Racing GT-7 in Noble Gold with Yokohama Tires(rear) 18x11-inch Volk Racing GT-7 in Noble Gold with Yokohama TiresInterior:Bride Zeta III seats, Takata harnesses, Cusco six-point roll cage, Sparco Race steering wheel, Spoon titanium shift knob, Pivot gaugesICE:Zapco sound system, Kenwood Excelon X990 head unit, Zapco components, amplifiers, subwoofers in custom enclosures

Mercedes S-Class four-door cabrio

When rumors first broke in June that Mercedes was planning a four-door convertible concept car based on the Mercedes S-Class, enthusiasts around the globe were surprised, and perhaps somewhat confused.Of course, the idea isn't entirely new. In the 1950s, the German automaker offered a four-door convertible called the Mercedes 300.But more surprising than the prospect of a four-door convertible concept are reports from Automotive News Europe today that the vehicle could become a production car within a year. A source within Mercedes told the trade publication the company will produce the niche V12 rag-top for the 2009 model year. The concept will be on display at the Detroit auto show in January.

Commodore SS V Unveiled To The World

Australia's Holden unveiled the all-new Holden Commodore range, designed and engineered to extend a decade-long record as Australia's best selling car.The fourth generation Commodore is safer, offers more technology and delivers more features and value than ever before. Interiors, exteriors and major mechanical features have been totally redesigned or upgraded, representing the most clean-sheet car program in Holden history.Holden’s sports performance hero SS V model and prestige leader Calais were chosen to debut the new Commodore at an event in Melbourne.Commodore’s design theme is enabled by an increased wheelbase which moves the wheels closer to the car’s corners, delivering a powerful European-styled stance on the road.GM Holden Chairman and Managing Director, Denny Mooney, said the Commodore was designed to excite buyers about Australian cars and enhance Holden’s future as the largest automotive manufacturer in the country. He announced a revised model line-up for the new range, including a new name to Holden, Omega, to replace Executive and Acclaim.“We are also adding extra class with the introduction of a new concept, the V Series, to highlight our top-of-the-line offerings. This will commence with the SS V and Calais V,” he said.“ The six-liter V8 will stamp its authority with peak power and torque of 362 bhp and 391 lb-ft which will really deliver the performance Holden buyers know and love.“We will introduce a new six-speed automatic transmission for V8 models, sharing it with GM’s premium cars such as Cadillacs and the Chevrolet Corvette.“We have introduced all-new front and rear suspension systems to provide outstanding handling without sacrificing ride comfort. The car’s microprocessing capability has more than doubled and allows us to provide new levels of safety and user-friendly features.”The Holden Commodore SS V will go on sale in Australia in August 2006. Pricing and full specifications and features will be announced closer to the start of sales.

Specifications:Engine:Type: V8 Displacement cu in (cc): 364 (5970) Power bhp (kW) at RPM: 362(270) / n.a. Torque lb-ft (Nm) at RPM: 391(530) / n.a. Brakes & Tires:Brakes F/R: ABS, vented disc/vented disc Tires F-R: n.a. Driveline: Rear Wheel Drivesource,"www.rsportscars.com"

BMW 3 Series Coupe 2007

Since its launch in 1975 the reassuringly expensive BMW 3 Series has become the motoring icon of corporate greed – the middle manager’s chariot of choice. As integral a part of the upscale lifestyle as an espresso machine and exotic holidays, it is a cultural phenomenon and the new 335i Coupe should secure entry into folklore.

Most business-class custodians that restrict their journeys to our motorway system will simply never understand how good their car is. The real core virtues of the middle managers’ outside lane pounder of choice will simply stay a secret, well hidden behind the traction control button and comfy leather seats. But inside this fifth generation 3 Series, beneath the gentile veneer, there’s a top sportscar just waiting to show a clean pair of heels to anything in its class and a good few besides.

When the next generation, V8 M3 arrives in 2007 it will have more than 400bhp and be a technical marvel, but it will just be too much car for many buyers. This 306bhp machine is just a few ponies down on the outgoing M3, which has been hailed as one of the best sportscars in the world, so has all the performance any sane individual would want and creature comforts, too.While the saloon appeared last year, this was the debut turn of the Coupe, a sleeker, sexier animal with a lower roofline and swooping features. Only the side indicator repeaters, rear badge and door handles have been carried over from its more sensible sibling on the outside. Only real aficionados will register anything other than a BMW 3 Series in front of their eyes, but those that know will respect you more, which is what the Roundel logo is all about.

And the only definable loss is that meaningless middle seat in the back that has been replaced with the continued centre console. The raked roofline doesn’t pillage the space inside and adults can comfortably settle in for a long-haul trip. For the lucky ones that don’t need to worry about the child seat in the back, the looks, predator poise and handling prowess of the coupe are more than worth the minor cost.The styling, while clean, efficient and much muscular, BMW Chief Designer Chris Bangle has stood accused of everything from heresy to blindness in his time. The 3 Series is a seductive looking machine in the flesh, though, and the 335 Coupe combines long, organic flanks and a large calibre snub nose with devastating effect.

The major delights lie beneath the skin here, though. The 0-60mph time of 5.5s is more than enough to keep the 335 in touch with more or less anything with four doors. And with 306bhp and 295lb/ft of torque at its disposal, it would undoubtedly keep charging hard beyond 155mph, when the electronic limiter kicks in and spoils the fun. For a proper four-seater this car is seriously fast.BMW’s first turbocharged petrol powerplant for decades was a big shock for the motoring fraternity, as the Bavarian marque has traditionally derided forced induction. To achieve these levels of power without a turbo would have required a much heavier V8, though, and this would have come with inherent handling costs so the German company opted for the twin-turbocharged inline six cylinder.Two relatively small turbos rather than one giant unit means that turbo lag is a thing of the past and the throttle response is instant as it is brutal. There’s just a constant wave of power underfoot and no flat spots in that immense torque curve, so the BMW just keeps pulling and on the right road could embarrass more cultured opposition.At any revs in any one of the six impeccably engineered gears just plant the right foot and the car will take off thanks to the effortless impact of the turbos. It comes with the high-strung harmonics of BMW’s inline six cylinder, but this time there’s a hissing, burbling backing track of the turbos spooling up. This is the kind of noise that invites just a bit more effort on the next bend, the kind of hard-edged note that awakens the racing driver in us all.It holds the road like Velcro, too, allowing the driver to pour on the power through the bend while the electronics kill any over enthusiasm before it gets to the wheels. There’s two levels of traction control if you want to feel the back end slip out of line a little and enjoy BMW’s famed 50/50 weight distribution to the full. Steering is alive and rapid in its response and while the 335 squashes imperfections in the road so well we could cruise on broken B-roads at motorway speeds, all the important information is fed through to the cabin. It isn’t an every day thing to send a car sideways at a roundabout, but it’s nice to know when the time arrives the 335 Coupe is as well balanced as the Bolshoi ballet at and beyond its limits.Despite being bigger and hosting a wealth of extra equipment, including DSC, which keeps the brakes dry in wet conditions and even anticipates heavy braking, moving the pads closer the discs, the 335i Coupe weighs less than its predecessor. Extensive use of aluminium in the basic construction helped keep the BMW to a lithe 1620kg and that shines through on every tightening bend.This commitment to the apex comes at a price, of course. Barge-like Mercedes leave the hard-charging BMW in their dust when it comes to comfort and the corresponding Audi feels a more complete car. But for the upscale young professional that likes taking the long road home, none of them come close to the 335 on sheer fun factor.And there is just one other cloud on this twin-turbo’s horizon, too, BMW’s next release – the 335d. This fuel-sipping diesel will be even faster, so the perfect reviews are almost writing themselves already. The diesel’s only downfall is the automatic box, as the near perfect six-speed manual in the 335 simply can’t take the torque, and this is by far most enticing option for serious drivers. It’s a good semi-automatic, but if you’re going that way then wait for the oil-burner that could single-handedly rewrite the rules on diesel motoring.The BMW 3 Series might be the icon of corporate avarice, but the reassuringly expensive 335i Coupe also happens to be one of the best everyday cars in the world.