Street Sleepers

A sleeper or Q-car is a car that has high performance and an unassuming exterior. Sleeper cars are termed such because their exterior looks little or no different from a standard or economy-class car but internally they are modified to perform at higher performance levels. The American term possibly comes from how an aggressive animal can seem gentle or perhaps friendly until awoken, while the British term derives from the Q-ships used by the Royal Navy.

Some cars are equipped this way at the factory to suit the tastes of those who want performance without attracting attention of the police or car thieves. For instance, many high-performance sedans look hardly any different from the lower-powered models in the range. Cars with obvious external badging, or overt visual elements that give the impression of high performance, are not true sleeper cars.

Kit Cars

A kit car is an automobile that is available in kit form, which means that the client buys a set of parts and needs to assemble the car themselves. Usually many major mechanical parts such as the engine and transmission are taken from one or more donor vehicles. Kits vary in completeness from as little as a book of plans to a complete set of all the components required.

The definition of a kit car is usually taken to mean that a number of kits are produced by a manufacturer for sale to the public. A car built at home as a one-off to the designs of its builder is termed a Special.

Current kit cars are often replicas of well-known and expensive classics and are designed so that anyone with a measure of technical skill can build them at home, to a standard where they can be driven on the public roads.

Many car drivers react sceptically when they first hear about kit cars as it appears to them to be technically impossible to assemble a car at home and also use it on the public roads. They may also be worried that such a car would not subsequently pass the mandatory quality control (road worthiness test) that is required in most countries.

Several of today's sports car producers such as Lotus and TVR started as kit car makers.

Turbos

The turbocharger was invented by Swiss engineer Alfred Büchi. His patent for a turbo charger was applied for use in 1905. Diesel ships and locomotives with turbochargers began appearing in the 1920s.

A turbocharger, or turbo, is a gas compressor used for forced-induction of an internal combustion engine. Like a supercharger, the purpose of a turbocharger is to increase the mass of air entering the engine to create more power. However, a turbocharger differs in that the compressor is powered by a turbine driven by the engine's own exhaust gases.

The first turbo diesel truck was produced by the "Schweizer Maschinenfabrik Saurer" (Swiss Machine Works Saurer) 1938.

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.

The world's first production turbo diesel automobile was also introduced in 1978 by Mercedes-Benz with the launch of the 300SD turbo diesel. Today, nearly all automotive diesels are turbocharged