The Posaidon RS Is A Mercedes-AMG GT63 S 4 Door With Nearly 900bhp

A German tuning company has boosted AMG's already very powerful GT 4 Door to nearly 900bhp

16 Sep 2019

The Posaidon RS Is A Mercedes-AMG GT63 S 4 Door With Nearly 900bhp

The Mercedes-AMG GT 4 Door Coupe has a rather problematic name. It’s not really an AMG GT, it’s technically a five-door car, and just because it has a sloping roofline doesn’t automatically make it a ‘coupe’.

And yet, the GT ‘4 door’ is a tremendous piece of kit. It drives much sharper than a car of that size really should do, and it’s monstrously fast. With the GT63 S developing 630bhp and cracking 0-62mph in just 3.2 seconds, it has more than enough power. At least, that’s what we think - German tuner Posaidon is inclined to disagree.

Its riposte is called the RS 830. The tuning pack blesses the GT’s M177 4.0-litre twin-turbo V8 with new turbochargers, upgrades for the charge air-cooling system, performance air filters, freer-flowing downpipes and less restrictive catalytic converters. Working together with some software fiddling, you’re looking at 819bhp and 811lb ft of torque.

The 0-62mph time drops to 2.9 seconds, and with no limiter spoiling the party, the RS 830 will keep going until 217mph. The package - which includes gearbox control software tweaks - is €24,000

Want more power? You really shouldn’t, but for anyone not satisfied by that hilarious output, there’s also an ‘RS 830+’ options which bumps the GT up to 868bhp and 885lb ft.

If you’d prefer a different Merc with a silly power output, all of these upgrades are available not just on other M177 V8-powered AMGs, but also the M178 engines used in ‘proper’ AMG GTs.

Growing up on a diet of World Rally Championship highlights and lengthy Gran Turismo 2 sessions, a life in cars was as good as inevitable for Matt.

Comments

With all these crazy tuning companies producing these menacing horsepowers by using bigger turbos, anybody have any idea how bad the turbo-lag actually is? Is it all about the bragging right?

All about the bragging rights, no doubt. I remember seeing a highway-run of a 1000bhp single-turbo RS6 on YT, reached full boost at 3k rpm or something.

It more than likely uses twin scroll turbochargers which means lag is reduced a lot of not negligible

I forget what brand, but one of these companies tunes an SLS AMG to a 1000hp, but on a dyno it makes 700hp. Usually it’s just a bragging right, but companies like Klassen are the real deal

An upgrade like this typically uses what is known as a “hybrid” turbo. Meaning that you don’t swap out the whole turbo for a larger unit, but instead you swap out the intake and compressor wheels or the turbo with larger, better flowing billet units. This will retain almost the exact same spool characteristics while flowing a lot more air, and making a ton more power, especially on the top end.