Turbocharger

Turbocharging is a term used generally for any kind forced air induction through mechanical supercharger or with a turbine. The gas turbine is the most effective way to increase the internal combustion engine's power, known as a Turbocharger. Internal combustion engines are known to be very inefficient, using only one third of the energy resulting from combustion in order to rotate the crankshaft. The remaining two thirds are used for cooling, losing on the third for the exhaust system. For example, a naturally aspirated 200 hp engine throw the equivalent of 70 hp power as heat, directly on the exhaust pipe. However, a turbocharger uses exhaust gases, so most of the heat and exhaust gases are used to force more air into the engine.

The position of the turbocharger on the exhaust gallery restricts in some measure gas output from the engine, but power losses are much smaller than with a mechanical compressor. With a turbocharger the lost power is around 5-10 hp for each 100 hp the engine has. The size of a turbocharger is much smaller than that of mechanical compressor, so, bigger turbos can be added which increases the amount of air forced into the engine and the gain of the horse power is also substantially increased according to it's size.


The turbo compressors has 3 key parts: the gas turbine, bearings and air compressor. Gas turbine blades and air compressor blades are connected by a shaft mounted on bearings. Some turbines can support up to 2400 hp and have the option of ceramic ball bearings. There are several types of turbines, depending on specifications air compressor.



A: gas turbine blades
B: bearing and seal
D: shell gas turbine
E: plate separators
F: air compressor blades
G: air compressor casing
H: shell bearing
I: inlet mouth
J: outlet

2010 Volkswagen Polo GTI

The new Volkswagen Polo GTI has been unveiled, promising to be the fastest, most focused and cleanest performance Polo yet produced. The original performance variant of the Polo was unveiled in 1986 in the form of the G40 Coupé – a car that mixed a fast-revving, 113 Hp, supercharged engine with a low kerbweight and sharpened responses.

Fast forward 24 years and the new Polo GTI bears similarities with the G40. At its heart is a 1.4-liter TSI engine that uses a supercharger from idle through to 3,000 rpm at which point the turbocharger cuts in to provide boost. The result is an output of 180 Hp at 6,200 rpm and 184 lbs ft of torque from 2,000 rpm which, when aligned with a 1,184 kg kerbweight, allows the Polo GTI to accelerate from 0 to 62 mph in 6.9 seconds before reaching a top speed of 142 mph.

Despite a keen focus on performance, the new Polo GTI is capable of delivering 47 mpg on the combined cycle while emitting just 139 g/km of CO2.

The TSI engine is linked to a compact seven-speed, twin-clutch DSG gearbox that channels drive through the front axle. In addition, the Polo GTI is fitted with the XDS differential, an electronic cross-axle traction control system for improved traction and handling. The XDS system is a functional extension of the electronic limited slip differential (LSD) which is a part of the standard ESP system.

In order to sharpen responses, the Polo GTI is fitted with new springs and dampers which results in a 15 mm lower ride height than the conventional Polo.

Like its Golf GTI sibling, the Polo GTI features significant aesthetic changes. A new front bumper featuring a deep airdam is joined by a honeycombe grille element with horizontal red strips and a simple GTI badge. New headlight units complete with the option of LED running lights lend the Polo GTI an imposing new look.

Further back, a subtle sill extension wraps around the lower edge of the body while at the back a new rear bumper features a small diffuser and a pair of chrome-tipped exhausts. The Polo badge is replaced by a simple ‘GTI’ version.

Finally, a set of 17-inch wheels identical to those fitted to the Golf GTI are fitted along with a set of red brake callipers.

The changes continue inside the Polo GTI with revised dials, a new, flat-bottomed GTI steering wheel complete with small gearshift paddles and contrasting red stitching, aluminium pedals and new, heavily bolstered front sports seats finished in tartan trim. Subtle gloss black trim covers the centre console while the headlining is now finished in black.

The new Polo GTI is due to go on sale in Europe in the summer at which point pricing and specification will be announced.

Jaguar XKR

Jaguar will unveil the latest dramatic evolution of its supercharged XKR coupe at the Geneva Motor Show in March. This XKR delivers a significantly raised maximum speed – up to 174mph from 155mph – and bold styling changes that create an evocative and unique supercharged Jaguar.The XKR Coupe unveiled at Geneva showcases two new optional performance and styling packs – Speed Pack and Black Pack - that are introduced to the XK range at 2011 Model Year. Jaguar customers have the option to personalise their vehicle to create a car that offers even greater performance without compromising the refinement and luxury for which every Jaguar is renowned.By raising the XKR’s maximum speed the new car has extended its sporting credentials taking it even further into supercar performance territory.

Russ Varney, Chief Programme Engineer, XK Series, explains the philosophy behind the uprated XKR:

"With 510PS and 625Nm of torque, the XKR has immense reserves of power and acceleration which impress everyone who experience it. The car has always had the potential to reach speeds far beyond its original electronically limited maximum and many of our customers have expressed an interest in a car that can safely be driven faster where conditions permit. The new Speed Pack allows them to release some of that potential and give them control of the fastest Jaguar XK we’ve made to date.”