The current Mercedes-AMG A45 is a hugely powerful 2-litre, however, some German tuners have taken theA45 beyond 300 kph.

AMG’s de-restricted A45 S is an incredibly rapid super hatch.

Powered by the world’s most potent 2-litre four-cylinder engine, it will run a true top speed of 270 kph.

It would be rather arrogant to believe that one could improve upon AMG’s engineering, but the German aftermarket tuning industry is full of ambitious and talented specialists. One of those is Posaidon, which despite the very un-German name, is located in Mülheim-Kärlich.

The company’s latest offering is aRS 525 upgrade of the A45. Posaidon’s technicians swap out the factory turbocharger for a new unit and appropriately reprogrammed the 2-litre engine’s control electronics to extract more power.

With a new turbocharger and revised control algorithms, the RS 525 boosts 386 kW and 600 Nm. Those are very impressive outputs for a compact four-cylinder engine, and notable gains on the factory AMG A45 S settings of 310 kW and 500 Nm.

Posaidon is aware that increasing the A45’s power by such a large amount could overwhelm AMG’s 4Matic drivetrain, especially its eight-speed dual-clutch transmission. To that end, the software which governs this RS 525 upgrade’s shift patterns, has been adjusted to account for additional engine output.

On a high-friction surface, the Posaidon A45 will run 0-100 kph in only 3.4 seconds, placing it firmly in supercar acceleration territory. Top speed is perhaps even more impressive, with the Posaidon super hatch capable of 324 kph. That's 201mph in old money, a 200 mile an hour hot hatch!

Beyond its engine upgrade, Posaidon is also offering Evolution One rims for the A45. These wheels are sized at 20-inches and made from carbon-fibre, which means they only weigh 4.9 kg, radically reducing the vehicle’s rolling inertia.

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