2018 Porsche GT3 vs 2017 Mercedes AMG GT R – Video

2018 Porsche GT3

Replacing the former GT3’s 475-hp 3.8-liter, the new model’s 4.0-liter engine produces 500 horsepower. Torque is up, too, to 339 lb-ft compared with 324. Specifications junkies will note that those figures match those of the GT3 RS and the 911 R. Porsche did tweak the engine’s internals, borrowing valvetrain tips from the 911 RSR race car and adding a new oil pump, a stiffer crankshaft, a larger-diameter main bearing, and a mildly tweaked intake. The 4.0-liter flat-six is a mechanical beast that Porsche claims can propel the 2018 GT3 to 60 mph in just 3.2 seconds and runs out of steam at 197 mph. Those figures are for the PDK-equipped model; the stick-shift version’s zero-to-60-mph acceleration claim is softer (3.8 seconds), although top speed inches up by 1 mph to 198 mph.

 

 

2017 Mercedes-AMG GT R

Affalterbach turns up the wick by 74 ponies and 37 lb-ft for this revised version of the 4.0-liter twin-turbo V-8, giving the GT R 577 horsepower and 516 lb-ft of torque. To achieve that output, AMG employed new turbochargers, a revised intake, new forged-aluminum pistons with a higher compression ratio, and remapped engine-control software to exploit the fresh hardware. Maximum boost available from the valley-mounted turbos is 19.6 psi (up from 17.6 psi in the GT S), and the units spin at up to 186,000 rpm.

AMG claims to have lightened the flywheel by 1.5 pounds for quicker engine response, and the cooling system was upgraded to ensure full engine output even in high-heat and racing conditions. A dry-sump oiling system keeps everything lubricated even under high g loads. Constructed of thin-wall stainless-steel tubing and fitted with titanium mufflers, the GT R–specific exhaust saves a claimed 13 pounds over the standard car’s.