By 1975 the Porsche 911 had already been in the public eye for 12 years, in production models and also the racetrack, spearheaded by the top of the range Carrera RS models of 1974. But it wasn’t until then that the venerable 911 gained the power to truly exploit its sublime design. Early RSR prototypes had experimented with turbocharging in 1974, and it was this research work that paved the way for the introduction of one of the most famous 911 models of all time the Porsche 911 Turbo (aka the 930).

Unlike previous models, the 911 Turbo was given the bodywork to suit its power output, early models sporting the infamous ‘whale tail’ rear spoiler, brought in to help tame the 911’s twitchy handling by increasing downforce over the rear driving wheels and wider arches to accommodate fatter tyres. It helped achieve this, and also made it one of the most iconic designs to ever grace a bedroom wall. Later cars would be given an intercooler, which was located in the spoiler to maximise cooling – often mistaken to be the radiator by the layman.

The first cars were fitted with a 3-litre flat-six engine that produced an impressive 260bhp – a 50bhp improvement over the 2.7 RS. The huge turbocharger did wonders for power output, but it wasn’t without its foibles, early cars being famed for their horrendous turbo lag. Keep this in mind when considering which 911 is right for you.

By 1978 the model had evolved. An increase in engine capacity to 3.3-litres combined with the new spoiler-mounted intercooler squeezed a further 40bhp from the engine, peak power coming in somewhere around the 300bhp mark. This gave the 911 Turbo truly legendary performance, and its homologation into the FIA Group 4 competition allowed Porsche to showcase it on the racetrack.

Amongst other prestigious competitions, the Turbo was entered into the renowned 24 Heurs de Le Mans, where it had some memorable battles with the BMW 3.0 CSL ‘Batmobile’.

While values of 911 Turbos are on the up, the investor’s choice is the ‘Flachbau’ or ‘slant nose’, which was an option available through Porsche’s special order scheme. Rather than the normal 911 front, each Flachbau was reworked by hand to include a more aerodynamic wedge shape. An expensive option when new, these cars are now highly sought after. A performance kit was also added to these prestigious models, upping power to 330bhp. This was achieved with the addition of a 4-branch exhaust system, modified rockers and a beefy intercooler.