Lead Vehicle Artist Casey Ringley goes under the hood of three absolute gems from Porsche
Porsche 924 Carrera GTP
This one is a “funny” little piece of history thanks to those three letters at the end of the name― GTP. When Porsche introduced a 924 Turbo model there was not enough time to meet homologation requirements for it to run in the production GT category as intended. Simple solution? Just run it in the GTP class against other full-on prototypes where the rules were effectively “have a roof and a minimum weight for your engine size”.
What did this mean for the 924? About 300hp disadvantage―and as for the road car aerodynamics, who cares, the 924 Turbo would be racing no matter what!
There is a fantastic documentary video of the car’s restoration over HERE where the drivers all talk about how great the handling of the 924 GTP was―high praise indeed when the group includes five-time Le Mans winner Derek Bell.
And that great handling paid off big-time when the 924 entered Le Mans in 1980 for a really wet race. Despite being a good 50mph down in top speed and lapping 30s slower in qualifying, the 924 GTPs used their handling strength to pull off a fantastic result of 6th overall (3rd in class) with the other two cars in 12th and 13th.
Design-wise, the car is both very similar and very different to the 911 Carrera RSR 2.8 we have in-game from the “Porsche Legends” DLC. The differences, obviously, are that this one is front-engine with a 2.0L turbo 4-cylinder sourced from Audi. Doubling boost pressure from the 924 Turbo road model to 2.5bar, it cranks out a seriously astonishing 320hp with a milk-smooth torque curve. Power is fed through a 5-speed manual Getrag G31 much like the road car but with a wide range of ratios to choose from for race use. A clutch-type limited-slip differential with symmetrical 40 percent lock is standard issue, much like in the 911 Carrera RSR and even the Porsche 908/03.
Engine position, roll cage addition, and general lightening of the chassis make for a total car weight of 945kg with 52 percent rear balance. Suspension uses struts at the front and trailing arms at the rear, like the 911 Carrera RSR; spring and damper settings for that car also work here to great effect. It even used brakes from the 917 parts catalog, another 911 Carrera RSR similarity.
For tyres, they fit the widest things possible. This car is around 100kg lighter than the BMW M1 Procar and with 160hp less, but it has more rubber at both ends of the car resulting in a car that has a surplus of grip in the dry and wet. While it can struggle on top speed tracks, it is so easy to chuck around that time can be made up quickly in twisty sections of tracks, and it has come out ahead in testing in-studio at a few shorter tracks.
An absolute gem of a Porsche this one, and a car that, in the right hands, is going to embarrass a few much more powerful cars.
A real unicorn here; Porsche only made one of these cars.
While Group B and the 959 are largely remembered for rally racing, circuit racing was always part of the plan, and the 961 was to be Porsche’s customer car in that regard. The end of the Group B era along with the cost of a 961 compared to competitive Group C machinery cut those plans short, and left us with only one example of what was, for nearly 30 years, the only AWD car to race at Le Mans.
Chassis construction was not all that different than the road-going 959 S model from our “Porsche Legends” DLC. The usual strengthening and lightening measures were undertaken and the highly-computerized AWD system was simplified to a fixed 20:80 power balance front to rear while the ‘zero-lift’ aerodynamics were bolstered to produce some downforce for the necessary cornering grip at the expense of a higher drag coefficient.
The 959 engine, meanwhile, which was in turn a detuned 956/962 C race engine, was swapped back out for a Group C racing version of the 2.85L twin-turbo flat-6.
The race-spec engine brings power up to 680hp @ 7,800RPM and drives through a 6-speed gearbox just like the case from the 959 S, but with a range of ratios as setup options. For Le Mans, they ran the rear-end with a spool axle as a reliability measure (fewer moving parts to break) but you can be sure it would have run a clutch-type LSD at the rear had it raced in a full WSC season; ours does that with a typical 40/60 percent lock differential at the rear.
Wider fenders, mild diffusers on the flat floor, and an aggressive rear spoiler cost about 20 percent in drag increase over the 959 S for a gain of roughly 500lb downforce at 150mph. Not a huge amount, but very welcome to help stabilize the 1,150kg car in cornering and under braking.
The extra drag, though, does limit top speed to 205mph down the Mulsanne Straight; about the same as the 959 S road car despite the extra power, and some way off the top Group C cars it raced against. Still, a respectable number.
Tuning the suspension proved not to be a difficult job at all. The 959 S had already forgone the fancy, adaptive, computerized suspension of the 959 Komfort model in favor of fixed-rate dampers and ride height. Turns out that, being some 400kg lighter, the 961 races extremely well on the same springs and dampers as the 959 S. Drop the ride height, stiffen the anti-roll bars to account for increased cornering grip from the racing slicks, and it’s ready to go.
This is probably my favorite handling car in its class. Maybe not as exciting as the Ferrari F40 LM’s turbo lag or the Mustang’s pure torque, but it inspires huge confidence on corner exits where you can plant the throttle to the floor and let the AWD system pull the car out with just the right amount of slip angle.
The Audi 90 IMSA GTO in-game finally has something that can compete with it in the rain.
Porsche 917 LH
The 917 LH models are very similar to the 917 K (that came with the “Porsche Legends” Pack) on fundamental levels. The main evolution here is in the aerodynamics which have a heavy focus on top speed for Le Mans.
Early iterations of the LH bodywork were great for drag reduction, but also generated significant aero lift at the rear. That deficit had largely been removed on the 1971 model that we’ve simulated for the “Spirit of Le Mans” Pack with wind-tunnel tests showing about 300lb downforce @ 150mph with a stable balance of 20-25 percent front. That’s enough to hit a solid 390kmh (!) and feel perfectly comfortable taking the Mulsanne Kink flat out.
The longer bodywork plus other detail changes of the LH model pushed them up above 820kg and closer to 66 percent rear weight.
See our “Physics of Porsche Legends” DLC thread for more notes about the common engine and gearbox used by these cars HERE.
The Project CARS 2 Season Pass offers all four DLCs plus the Motorsport Bonus Pack, all at a discounted price.
The Spirit of Le Mans Pack is available now for PlayStation 4, Xbox One, and (PC Steam).