For its latest project, the German tuners at G-Power turn their attention toward the Mercedes-AMG SL63 and push its 5.5-litre twin-turbo V8 to 789 bhp and 811 pound-feet. For comparison, the mill makes 577 bhp and 664 lb-ft in stock trim, so this is quite a major upgrade.

Gallery: G-Power Mercedes-Benz SL63

Making such a power boost happen requires G-Power to fit a few new parts. Mechanically, the firm offers a larger pair of turbochargers for 5,420 euros (£4,750 at current exchange rates), revised downpipes for 4,084 euros (£3,580), and a redesigned stainless steel exhaust for 1,807 euros (£1,585). There's also new software for 3,319 euros (£2,910) that configures the engine to make the most of components. Removing the usual top speed limiter is an extra 500 euros (£440).

With all of these new parts, an SL63 is able to sprint to 62 miles per hour in a brisk 3.5 seconds, versus 4 seconds for a stock example to reach 60 mph. Without the top speed limiter, the luxury roadster can reach 211 mph.

G-Power largely leaves the SL-Class' look alone, but the firm offers a set of forged 21-inch wheels for 7,521 euros (£6,595). They feature five pairs of double spokes with machined faces and black details.

Mercedes currently has a new generation of the SL-Class on the drawing board. The designers intend to create a roadster that evokes the iconic 300 SL, suggesting the possibility of a curvier body instead of the current chiselled appearance. From a mechanical perspective, the roadster should be lighter through greater use of aluminium and the return to a soft top rather than the folding metal roof from the last several generations.

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PRESS RELEASE – AMG Models G-POWER SL 63 AMG: 800 hp in the big roadster classic

While the product life cycle of vehicles tends to be shortening nowadays, there are still exceptions that defy this trend. Among them is the big roadster classic from Mercedes-Benz: the SL. Manufactured for upwards of ten years, its previous generations have always been on the market for an exceptionally long time. The current model – soon to enter its eighth year – is still fascinating, luxurious and elegant. And the SL 63 AMG version, powered by a V8 twin turbo, also features a superior drive and a generous dash of sportiness. The performance specialists of G-POWER from the Upper Bavarian town of Gachenbach have now turned their attention to this powerful roadster, helping it reach new heights in terms of performance and allowing it to enter unforeseen territory at supercar level.

Key facts: G-POWER SL 63 AMG (R231)

• 800 hp/588 kW at 5,750 rpm (+215 hp/158 kW) • 1,100 Nm at 4,500 rpm (+200 Nm)
• Top speed: >340 km/h
• 0-100 km/h: 3.5 s

• G-POWER V3 performance software: EUR 3,319.00 • Top speed increase: EUR 500.00
• Turbocharger modification: EUR 5,420.00
• Stainless steel exhaust collector: EUR 1,807.00

• Stainless steel downpipes with sports catalytic converter: EUR 4,084.00 • Stainless steel exhaust system: EUR 3,866.00
• Set of 21" G-POWER HURRICANE RR forged wheels, incl. 265/30 ZR21

and 295/30 ZR21 tires: from EUR 7,521.00

(All prices are net.)

The 5.4-liter M157 eight-cylinder generates a smooth 800 hp/588 kW thanks to G-POWER's optimization work. For the vehicle in question, this means an increase of 215 hp/158 kW over the basic model. Measured against the performance of the current model, which was slightly reduced to 571 hp/420 kW as part of the conversion to the Euro 6d-TEMP emissions standard, the increase is as much as 229 hp/168 kW. It takes just 3.5 seconds to sprint to 100 km/h thanks to this increase in power, meaning an improvement of more than half a second compared to the – by no means slow – SL 63! The top speed isn't reached until well beyond the 340 km/h mark. A combination of software and hardware optimizations is responsible for the improvement in engine output. On the one hand, the roadster has the proven G-POWER V3 performance software in conjunction with the removal of the speed limiter, which is separately available.

This is enhanced by a new exhaust collector, as well as downpipes with sports catalytic converter and an exhaust system, all of which are made of stainless steel. To round things off, the two turbochargers are modified: As usual, G-POWER fits larger turbine and compressor wheels, CNC-optimized housing and enhanced compressor turbine blades. This reduces the exhaust-gas back pressure and exhaust temperature, while the air throughput increases.

In terms of look, a new wheel set underlines the exceptional position of the G-POWER SL 63 AMG. The open two-seater features a set of 21" 'HURRICANE RR' forged rims made using ultralight high-tech aircraft aluminum. The twin-spoke wheels are characterized by the G-POWER 'DIAMOND CUT' high-sheen finish wheel customization in jet black. The 265/30 ZR21 and 295/30 ZR21 high-performance tires are extremely wide, ensuring ample grip and safe road holding, even at high speed.

The video available at the following link provides an excellent impression of the G-POWER SL 63 AMG in action: