Everything You Need To Know About Porsche's New GT3
It's so much more than a manual gearbox
Since the unveil just a few hours ago, Porsche has been flooding the internet with information about their new GT3. In addition to the official press release, Porsche's head of GT cars, Andreas Preuninger, conducted several interviews that all dropped at the same time. We've taken the opportunity to merge everything here in one location for you to easily see every tidbit of information you'd ever want or need to know about Porsche's newest GT car. Andreas called this the 'best GT3 yet', so this is all of the reasons why he might think that.
Porsche's stated goal with the second generation 991 GT3 was to increase downforce levels while maintaining similar overall drag coefficient levels, or perhaps increasing them even a little. As it so happens, they seem to have done just that. With the last GT3, Porsche simply maintained the flat underfloor of the standard 991 Carrera, but with this model, they've added a few air acceleration tricks. In addition to a 911R-style rear diffuser, the GT3 also has had the floor amended with a second diffuser ahead of the rear wheels to speed the air going into the rearward diffuser.
Because of the underbody aero and a more aggressive front fascia, Porsche was able to move the rear wing around a bit to gain downforce without messing up the aero balance. The new wing uses the same basic structure as the old wing, with more pronounced wing endplates and a slightly different location. It's been moved up into the clean air stream by 20mm, and it's been moved rearward 10mm. It may not seem like much, but the difference is clear. The new GT3 produces about 155 kilos of downforce at its top speed, which measures about the same as a 997.2 GT3 RS, and about 20% more than the 991.1 GT3, while drag forces remain unchanged.
Preuninger calls this new four-liter engine a "Quantum Leap" over the gen-one GT3's 3.8-liter, and even significantly improved from the current GT3 RS. Because Porsche now races this engine family in all of their GT3 Cup cars, GT3Rs, and even the mega 911 RSR, they claim to have learned advancements on the new GT3 engine directly from motorsport. The new engine has a larger diameter crankshaft with larger mainshaft seals. Somehow Porsche has created a system of oil passages that route directly through the crankshaft to lubricate the bearings, but even with those channels drilled into the crank, it is more rigid. This is allegedly the same four-liter engine found in the GT3 Cup, but with a different intake and a quieter road-legal exhaust.
The engine also features new motorsport-derived pistons, tighter sealing high-compression rings, and a new cylinder liner. The most important change, however, is the switch from hydraulically adjusted valve lifters to a mechanical method. Andreas, here, claims that the new system never needs any adjustment, because of the quality of materials they used from the outset. They've allegedly run one of these engines on a stand for 300,000 kilometers and the valve clearances didn't change even half a tenth. Because of this wholesale valvetrain change, the new engine is a bit lighter, can run a lower oil pressure, and spins slightly more freely, explaining the bump from the GT3 RS' 8800 RPM redline to the new GT3's 9000 RPM.
Furthermore, the intake has been amended with a second flap. Depending on throttle application, the flaps will open to adjust the torque curve for what is needed. Like the old varioram systems found in 993 Carreras, the intake can effectively change resonances and chambers to produce more torque down low for a slightly flatter curve. The new valvetrain, new crankshaft, new cylinder walls and pistons and the new resonance intake system add up to a kick ass engine.
There isn't much to say here. You have a choice now, which is great. The prior GT3 was PDK only, but the Porsche fans that wanted an engaging driving experience shouted about not being able to buy one with a manual transmission. Porsche developed the 6-speed manual gearbox, and now you can get one in the GT3. If you're still all about ultimate lap times, you can grab one with the same 7-speed double clutch as before. The PDK comes standard, but the manual is a no-cost option. Unfortunately, because of the way the new crankshaft is built, Porsche mandates a dual-mass flywheel for the manual transmission cars, adding some rotational weight and damping from what people loved about the 911R.
Porsche suspects the 911 GT3 will see a 60:40 split of transmissions, favoring the PDK. If you shouted about wanting a manual GT3, you owe it to yourself, and to Porsche, to go put your money down right now.
Andreas calls the new suspension 'very RS-ish' with rear helper springs, a new damper setup, etc. The new dampers are said to provide better backroad stability and comfort, while still being a stiffer and more compliant setup for track use. The steering is updated with a new software tuning program using the same hardware. Tweaks by Porsche have continued making this steering better and better from the GT3 RS to the GT4 to the 911R. They claim this is the best steering feel they've had from this system.
Limited Production? -
Porsche says they will not limit production of the GT3 as they did with the 911R, so if you want one you'd better get on the list to have it built ASAP. Production limits will always make it impossible to build 10,000 of these, but as demand allows they should be able to produce. If you've got $150,000 sitting in your pocket, turn that into a GT3 delivery this fall, and make sure you order the manual!
For more, check out Andreas Preuninger's discussions with DRIVETRIBE, EVO, and Pistonheads below.
Read the full Pistonheads interview here, and check out their walkaround video below: