Power can be moreish. So when Mercedes-AMG stuffed two turbochargers in the GT S’s nose, it was a safe bet the aftermarket crowd were going to have it push out more puff.
Among the first to try are tuners Renntech, who jumped at the opportunity to squeeze more from the car’s 4.0-litre V8 with its newly released engine upgrade. It’s also developed a suspension upgrade, and tested both at the Nurburgring for a final sign-off.
The engine package focuses on the GT S’s turbochargers snuggled in the engine’s vee, where Renntech have swapped in lightweight compressor wheels.

High-flow filters feed the turbos more air, while new dump pipes stuffed with sports cats operate downstream.
An ECU tune oversees the whole operation, and all up allows the engine to drum up 533kW and 890Nm. That’s a whopping amount, equating to 158kW and 240Nm more than the stock car’s outputs.

At the same time Renntech has released new lowering springs for the car. They slip over the stock dampers and drop the car by a signficant 1.5-inches. Thankfully they also retain the car’s electronic damper control.

Pictures via Renntech