There's more to the 2018 Porsche 911 GT3 than meets the eye. "We didn't concentrate on making the car look different," says Andreas Preuninger, head of Porsche's GT car development. "We concentrated on making it more efficient." So though it looks familiar, the new GT3 features significant engine, suspension, and aerodynamics upgrades, all designed to make one of Porsche's sportiest 911 variants even faster.
The new GT3 is powered by a 4.0-liter naturally aspirated flat-six that develops 494 hp at 8,250 rpm and 339 lb-ft of torque at 6,000 rpm. It's not same 4.0-liter engine used in the current GT3 RS, however. Optimized to reduce internal friction, it features, among other things, a new crankshaft with larger main bearings and a redesigned oiling system, a new variable intake manifold that's designed to increase low-end and midrange torque, and a redesigned valve train that does away with hydraulic lifters. Two ram air scoops on the carbon fiber engine cover funnel air directly into the intake system. The resulting high-pressure airflow at speed is said to deliver at least 10 hp more than the engine's rated output on a static dyno.
Preuninger says the new GT3's engine is a big step up from the 4.0 liter in the current RS and a quantum leap compared with the 3.8-liter powerplant in the previous GT3, pointing out many of the changes that have been made to improve the 911's performance on the racetrack. "We now use this engine in the GT3 R and RSR race cars," he says. " It's the same raw block—a new motorsport block, let's put it like that—we use for all the race car engines. It's all one family."
Underneath the familiar sensual curves of the 991-series 911 bodywork is a revised suspension that's lighter, with new geometry up front and helper springs all round that deliver more stiffness and precision on the track but a smoother ride on regular roads. The PASM calibration has been changed so it's a little firmer on the track. There are new harder bushings in the front wishbones, but the damper valving has been tuned to improve rolling comfort on back roads. The ZF rear-wheel steering system pioneered on the previous-gen GT3 has been retained.
The 2018 GT3 rolls on the same 20-inch forged alloy wheels as the old car, but Preuninger says that's only because his team couldn't design new ones that looked better and were just as light. The rims are wrapped in new specification and new compound tires, either Michelin Pilot Sport Cup 2 or Dunlop Sport Maxx, 245/35 ZR20 up front and 305/30 ZR20 at the rear. Standard brakes feature 15-inch steel rotors and new calipers designed to reduce drag. Porsche's PCCB setup, which delivers 16.5-inch carbon-ceramic rotors up front and 14-inch items at the rear, is available as an option.
To the joy of many Porsche faithful, the six-speed manual transmission used in the 911R is also available as an option. Preuninger says that though the D-I-Y GT3 is about 0.5 second slower to 60 mph than the standard PDK-equipped car, the stick shift will appeal to owners who aren't interested in chasing the ultimate lap time. Manual transmission cars come equipped with a fixed rate limited slip differential, and PDK-equipped cars get the more sophisticated electronically controlled differential for ultimate traction.
Careful attention has been paid to aerodynamics. A new front fascia improves cooling and delivers better laminar flow around the front wheels. At the rear is a new wing that sits farther rearward and almost an inch higher. But what's more interesting is the stuff you can't see. This new GT3 is the first 911 with an aerodynamic floor, with turning vanes behind the front axle that guide air into a rear diffuser. The result, Preuninger says, is a 20-percent increase in downforce compared with the old GT3 and no increase in drag.
Despite the outcry from enthusiasts over the lack of a manual, the previous GT3 was the most successful in the 18-year history of the nameplate. Now with a manual transmission back in the mix, the new GT3 is a car that will appeal both to aficionados who enjoy deeper interaction with the art of driving, as well as hardcore track rats. "It's the best GT3 ever," Preuninger says. He pauses, then smiles. "Because it's the newest one I've done. I always say that."