Road X-tra Racing.
The team at IMSA GmbH has quite the extensive history with Mercedes-Benz/AMG and Lamborghini vehicles, and their owners. Their clients want something special that sets them apart in terms of style, performance, and exclusivity. The new IMSA RXR One is just that. The idea for the limited-production model was brought forth by a client that wanted a more practical daily-driving supercar instead of their tuned Lamborghini.
“We came to the conclusion that the AMG GT S was the best car on which to base this project since it already ticked all the boxes in terms of practical packaging, its front-mid-engine, transaxle gearbox layout, and race-style double wishbone suspension,” said Holger Mohr, Founder of IMSA GmbH.
Thus, the IMSA RXR One was born.
The IMSA team focused on four areas to create the ultimate daily-driving supercar based on the Mercedes-AMG GT S: weight reduction, power increase, chassis upgrade, and aerodynamic enhancement. Each customer of the limited-production supercar is given the ability to pick their own paint colors, interior trim options, and more, making them each a truly bespoke model.
The weight reduction aspect of the IMSA RXR One saw much of the body work replaced with carbon fiber paneling alongside other lightweight materials being used in other areas. This resulted in a total of 661 lbs. cut from the factory Mercedes-AMG GT S for a total DIN weight that’s just under 2,866 lbs.
In terms of the power increase, the M178 4.0-liter, twin-turbocharged AMG V-8 engine was extensively modified. The factory steel crankshaft was lightened and balanced, and mated with forged pistons and H-section connecting rods. A new custom intake system sends air to each cylinder bank through the modified turbochargers and larger throttle bodies. A twin-row intercooler system and individual water-cooling circuit helps ensure each turbocharger operates at the right temperature. CNC ported, polished, and gas-flowed cylinder heads improve airflow while a lightweight Inconel exhaust system cuts down on weight and backpressure.
After all the engine upgrades, the IMSA RXR One produces a monstrous 860 bhp and 738 lb-ft. of torque. That kind of power output forced IMSA to reinforce the factory AMG SPEEDSHIFT dual-clutch gearbox. Here, a new competition-grade clutch pack, forged intake driveshaft, high-pressure valves, independent oil cooling system, and rear differential oil cooler was installed.
In order to properly put that power down on the pavement, the Mercedes-AMG GT S was given a full-on chassis upgrade during its transformation to the IMSA RXR One. Both the front and rear tracks were extended with the suspension geometry being revised to accommodate. Forged wishbone mounts with Rose joints, forged wheel hubs, and longer driveshafts were installed to take advantage of the wider track. New adjustable competition springs and dampers give drivers the ability to tailor their suspension for a specific racetrack.
Hitting the pavement on the IMSA RXR One are IMSA Racing forged alloys that measure a staggered 20 x 12.0J up front and 21 x 12.5J at the rear with sticky 305/30 ZR20 and 315/30 ZR21 Pirelli P Zero Trofeo R tires. Sitting behind the new wheels are lightweight carbon ceramic brakes with high-performance pads.
Visually, the IMSA RXR One has all the looks to back up its incredible performance. Autoclaved carbon fiber body work was designed by a state-of-the-art computer program and tested in a wind tunnel to optimize the downforce and drag.
The beefier carbon fiber fenders increase the width of the IMSA RXR One by 110 mm up front and 130 mm at the rear, and are connected by a set of dep side skirts. A new carbon fiber front bumper and spoiler combo help optimize engine cooling and cut lift while a new hood with air intakes and vents provides a ram intake for the turbochargers. Carbon fiber also makes up the roof, trunklid, and rear wing spoiler. The IMSA RXR One also boasts a completely flat underbody ending in a deep rear diffuser that keeps the supercar sucked to the pavement.
Inside, the IMSA RXR One features a full roll cage that improves safety and works with the suspension to increase stiffness and torsional rigidity. Carbon fiber sport seats with six-point harnesses hold both driver and passenger in place during high-speed cornering.
The new IMSA RXR One based on the Mercedes-AMG GT S will be available as a limited-production vehicle only. Pricing has not been announced.
IMSA RXR One Specifications
Displacement: 4.0 liters
Number of Cylinders: V-8
Maximum Horsepower 860 bhp
Maximum Torque: 737.5 lb-ft. / 1,000 Nm
IMSA RXR One Gallery
Source: IMSA GmbH