The original AMG GT Coupe was honed and sharpened with a series of faster and harder-hitting variants over the years—evolving steadily through the GT S, GT R, and ultimately the almighty GT Black Series. Now the second-generation car that was launched last year is beginning the same journey. AMG has already released details about the forthcoming 805-hp plug-in hybrid GT63 S E that will sit at the top of the range in terms of both price and performance. Now here’s another new version, the turned-up and track-focused AMG GT Pro which has been unveiled at the Goodwood Festival of Speed in the U.K.

Individual changes over the existing GT63 are small, but the cumulative result is claimed to be a significant improvement in performance when the car is driven on a circuit. The Pro's power output has been increased, cooling improved, and carbon-ceramic brakes added as standard. Track-biased tires will also be offered at no extra cost. According to AMG boss Michael Schiebe, the Pro is well suited to track use but without becoming harsh on-road, "to maintain a high level of day-to-day usability for a car of this type."

Engine Details
The adaptability of AMG's long-serving 4.0-liter twin-turbo V-8 means it has already been offered in outputs ranging from 450 to 750 horsepower and in both cross-plane and flat-plane-crank derivatives. The new GT63 Pro uses the regular cross-plane variant, which has only been modestly boosted when compared to the existing GT63, now making peaks of 603 horsepower and 627 pound-feet, increases of 26 hp and 37 pound-feet respectively. As with the GT63 it has 4Matic all-wheel drive and a nine-speed automatic gearbox that uses a wet clutch in place of a torque converter. Looking at AMG's own numbers, the 3.1-second acceleration to 60 mph is unchanged from the regular GT63, but the Pro is claimed to be 0.5 second faster from zero to 124 mph, dispatching the tougher benchmark in just 10.9 seconds.

Substantial cooling improvements, though, have more relevance to the AMG's intended racetrack habitat than the modestly raised output. The Pro gets double high-temperature radiators up front, plus separate rads for the front and rear differentials. The electronically controlled transfer case, which apportions torque to each axle, is also actively cooled. Externally, there are also larger side intakes in the front bumper to help channel air to the brakes.

Aerodynamics
The most obvious aerodynamic change is the arrival of a fixed rear wing at the rear that's finished in naked carbon fiber. There are also additional air deflectors beneath the car to accelerate airflow over the underbody and rear diffuser. AMG isn't quoting any overall downforce numbers but says the Pro has up to 66 pounds less aerodynamic lift over the front axle and 33 pounds more downforce at the rear. A set of 21-inch forged alloy wheels will be standard, and buyers will be able to choose between Michelin Pilot Sport 5 tires or the no-cost option of track-biased Pilot Sport Cup 2 R rubber.

The Pro also keeps the same battery of active dynamic systems as the regular GT63, including rear-axle steering, an electronically controlled limited-slip differential at the rear, and adaptive dampers that incorporate hydraulic cross-linking to dramatically reduce roll under cornering loads.

Although it will sit at the top of the range, the GT63 Pro is not going to be a limited-edition model, allowing the market to decide on its popularity relative to the other members of the clan.

We will get more details, including pricing, ahead of deliveries beginning early next year.