Porsche 997 GT3 RS 4.0 vs Porsche 991 GT3

The battle that has been going on and on and on again in the automotive industry: Old vs New. I’m comparing my former 997 GT3 RS 4.0 with its younger, slightly lower spec brother, the 991 GT3. Both cars have such an amazing technology and heavy engineering, but which one comes on top in my opinion? Well, let’s find out, shall we? Let’s start with the engine.

GT3 RS 4.0

Displacement : 4.0 litre
Stroke : 80.4 mm
Power : 493 hp @ 8250 rpm
Torque : 339 lb·ft @ 5750 rpm
HP/L Output : 125

GT3

Displacement : 3.8 litre
Stroke : -
Power : 475 hp @ 8250 rpm
Torque : 325 lb·ft @ 6250
HP/L Output : 125

Both engines have a similar specification, and an exact same figure on the HP/L @ 125 hp/l which makes both the 3.8L H6 and the 4.0L H6 one of the most powerful six-cylinder naturally aspirated engines in any production car. So, not much difference in the engine, let’s go for a drive..

For the first time in its 16 year production run, the 991 generation GT3 only has a 7-speed PDK that I absolutely love. Today, Porsche Doppelkupplung (PDK) is setting standards on the road, with gear changes that take place in milliseconds and with no perceptable interruption in the flow of power to provide faster acceleration and low fuel consumption.

And yet Porsche engineers still were not satisfied – at least, not with the development of the new 911 GT3. So they pushed the limits once again. Their goal was to produce a transmission with gear ratios specific to the 911 GT3 and with a 50% reduction in shift throw on the even crisper and more dynamic gearshift paddles. The result was a PDK perfectly tuned to match the 3.8-liter engine. This is the first time that it has been fitted in a 911 GT3, and it comes as standard. Around a road, the automatic mode works brilliantly, compared to the 997 4.0’s manual which - around a road doing 30-50 mph - is slightly jerky and because you have the third pedal, getting stuck in a London traffic will be an absolute nightmare for your left foot.

The number 1 thing I love about the PDK is the smoothness compared to other DCT’s such as BMW’s DKG which is not bad but, not as smooth as the PDK. It’s so good, I think it might be better than the DCT that you get in a Ferrari 458, which is one of the best DCT’s on the market. Another thing that I love on this car is the gearing. 911 GT3s have been criticized a lot for its gearing that doesn’t make sense. Now though, on the 991, I think they have fixed it. Fixed it properly.

Next thing that I want to talk about is the sound of a 991 GT3 with OEM sports exhaust system, oh my God. It sounds insane. The sport exhaust system of the new 911 GT3 has two front silencers, two catalytic converters and one rear silencer, which discharges into the central twin-tract tailpipes. The large volume of the exhaust system reduces exhaust backpressure and thus increases power output. The two Lambda sensors of the stereo Lambda control circuitry regulate the composition of the exhaust gas separately in each exhaust tract, while another pair monitors pollutant conversion in the respective catalytic converters. You can actually drive it in a residential zone without worrying your neighbours. But once you’re out of the residential zone, up towards to twisty country roads in the North, you can really hear this 6-cylinder scream. The best part is it can scream up to 9000 rpms.

high revving NA engine + a sports exhaust =

Another never-seen-before-on-a-GT3 feature on the 991 GT3 is the 4-wheel steering. Why did they decided to use this? Performance and everyday practicality. Hahahaha..what? So they made the 991 GT3 like a forklift for “performance and practicality”?. No, this isn’t just any 4-wheel steering. This 4-wheel steering system has an electromechanical adjustment system at each rear wheels. Those electromechanical adjustment system at each rear wheel enables the steering angle to be adapted based on the current driving situation, steering input and vehicle speed. The advantage for day-to-day driving: during low-speed maneuvers, the system steers the rear wheels in the opposite direction to that of the front wheels. This has the virtual effect of shortening the wheelbase. The turning circle is reduced to make it easier to park. The advantage for sporty driving: during high-speed maneuvers, the system steers the rear wheels in the same direction as that of the front wheels. Driving stability is increased by the virtual extension of the wheelbase and agility is enhanced by the simultaneous steering of the front and rear axles, especially during overtaking maneuvers on the racetrack. Can’t wait to take it to Silverstone and blast through track.

How about torque vectoring? Yes, like any other supercars, the 991 GT3 has a torque vectoring system called the PTV Plus (Porsche Torque Vectoring Plus). Porsche Torque Vectoring Plus is fitted as standard and has been specially adapted to the new 911 GT3. It operates in conjunction with an electronically regulated and fully variable rear differential lock. The results are perceptible, particularly at the limits of dynamic performance: greater traction, and a significant improvement in driving stability under the effects of load changes in corners and when the car changes lane. On surfaces with less grip, such as in the wet, the system strategically brakes the right or left rear wheel. This means that, whenever the car enters a corner, brake pressure is applied to the inside rear wheel. Consequently, a greater amount of drive force is applied to the outside rear wheel. This improves steering behavior and increases agility which works great and combine that with the 4-wheel steering, you’re in a car that can corner like nothing else. But, there’s a lack of something. The lack of “hardcore-ness” of the GT3 compared to the more traditional 997.1/2 GT3. The technology is great, don’t get me wrong, but, you can’t feel the satisfaction of doing rev matching, or the “feel” of a hydraulic steering, and then there’s the seats. For a street car, this is uncomfortable, for a track car, the regular standard 14-way power seats are not as supportive as the race bucket seats (which is a 4-figure option, typical Porsche, options, options everywhere). So, it’s lacking full capabilities as both a track car and a street car, don’t get me wrong, it’s not bad, but, they could’ve done it better.

Time to move to the Four-0. One of only 600. Is it because of demands? Nope. Its run of 600 units is dictated not by demand, but that thereafter its parts supplies will dry up; and at a price of £128,466, Porsche will make no money from any of them. But still, 130k is a lot for a Porsche 911. This is the greatest version of the greatest track focused car ever built. Porsche knows that they could have made thousands and charged half as much again for everyone. But they chose not to. The GT3 4.0 has a lot of mangling around with its parts, mostly from the RSR and the GT2/GT2 RS. It’s more than a standard GT3 RS with a bit more poke and a slightly bigger engine. Instead, it is a heady confection of Porsche’s most extreme road car, the GT2 RS, and its all-conquering racers, the GT3R and RSR. The Rose-jointed rear suspension with its helper springs is pure GT2 RS, the engine courtesy of the race cars, their long-throw crankshaft stroking the unit out to 3996cc, making this the largest engine ever to sit in the boot of a Porsche, and the current 991 RS also uses the same type of engine, a 4.0 L H6.

Look at the stats like the 0.1sec knocked off the 0-60mph time and it’s hard to see why. But drive the 4.0 RS and it’s blindingly obvious. No, you don’t feel the extra 50 hp, what you feel is the pull and the torque of this motor. Brutal. 997 GT3s have been criticized for its pesky gearing but on this, it feels better. Cornering around a circuit could be a gear higher than normal. For example, in my cousin’s 997.1 RS, going through the turn 2 hairpin at Brands Hatch uses the 1st or 2nd gear, in this? Maybe 2nd or 3rd.

On a track, the four-0 is really good and absolutely grippy with its new aero package that makes more downforce than any previous RS, those natty front winglets essential to balance the extra rear grip provided by that new rear wing with its 7-degree angle.

The place where the four-0 struggles is: The Road. Unlike the 991 which has a front axle lift kit, the four-0 doesn’t and taking it to a country road in Wales could be a disaster for your front splitter. Well, it is plastic so, replacing it shouldn’t be as expensive as, let’s say, a carbon fibre splitter but, scraping a 150k car will never sound good, right? And then there’s the manual gearbox, jerky at low speeds. But, just like what Salomondrin said, the harder you drive the four-0, the better it gets. But let’s face it, driving hard on a traffic-y public roads could only end well.

OK, how about in a wet surface? Crap. Tires are really, basically slicks. And around a city, fuel economy is worse, I’ll tell you that.

Which One And Why?

I think I’ll go with the GT3 RS 4.0, much more soul, much more fun, and of course, more hardcore than anything that you’ll find on any pornsite.