Group B was the name assigned to the new era of sporting regulations set out by the FIA for both rallying and sportscar racing in 1982. The regulations were left deliberately vague in order to entice the major auto manufacturers back into racing, especially rallying. They proved enormously successful with virtually every major automaker building a Group B-spec runner―and for the FIA, that was mission successful. Except for one minor flaw―they failed to predict what would happen when the best engineers from the best automakers in the world were given limitless amounts of cash.
The result was the fastest rally cars the world had ever seen―so quick that drivers began suffering from tunnel vision. The chaos that ensued―driver injuries, and deaths, along with countless injuries and deaths from spectators lining the rally stages to get a glimpse of these mad motors―meant the FIA had little choice but to ban the Group B cars after just three unbelievable seasons.
For the Fun Pack, three of these iconic Group B rally cars that would see an after-life as rallycross cars were recreated, and here Casey Ringley gives you an insight on how they were built for Project CARS 2.
Audi Sport quattro S1
We had great fun researching this car; it’s famous enough and cloned enough so that there is quite a lot of information for it on the web, and the more you read about it, the more amazed you become that it worked at all!
They basically started with an Audi 80 and kept cutting bits out of the middle until the wheelbase was only 2.2m to try and make the handling nimbler. That works in theory, but being an Audi, you still have the engine slung way out beyond the front axle, so early homologation versions had horrible weight distribution―something in the region of 62 percent front. Moving the cooling system to the rear and various other tweaks eventually helped get it to a 51:49, but all articles I’ve found still say that the chassis really works best if you are aggressive with it to force turn-in rotation.
Engine for the S1 version is generally described as peaky with gobs of turbo lag, and that comes through in the Project CARS 2 version―and it makes sense, too, when you take a look at the dashboard gauge that reads all the way up to 2.5bar (36psi) boost!
It’s a smooth 450hp, but you’ll find yourself waiting a bit for the power unless you row gears and help hold it high in the rpm range. They even ran it a few times with Porsche’s early PDK gearbox―also used in some Porsche 962C factory cars―to stay on boost better. In some old videos, you can clearly hear the difference in the PDK car shifting, and how smooth that unit flows through the gears. Impressive to think that the in-game Audi 90 IMSA GTO is an evolution of this same basic engine only four short years down the line, and it was then doing 700+hp with 10psi less boost. Turbo tech’ came on very strong in the ’80s.
The early quattro system, as in the race cars, used a kind of planetary/Torsen/viscous combination center differential. It allowed Audi to adjust fore-aft power balance, do some torque biasing on slip, and still lock-up if one end loses grip completely. This works really well when copied into our systems, and in-game, it feels a lot more typical of AWD road cars than something like the modern RX designs, and reminds me a lot of our time at DirtFish when Stephen Viljoen (Game Director on Project CARS 2) and I spent a day with the instructors learning the ins-and-out of performance driving on gravel and loose surfaces.
Front diff’ defaults to a viscous limited slip differential (LSD) and rear to a typical ZF-type Salisbury LSD, which appears to be how it ran most of the time.
Suspension is simple MacPherson strut all around. Aero is nothing special, but it does help stabilize the car nicely. Gearbox is the 6-speed manual it ran most of the time, with a ratio set pulled from the old FIA homologation forms. It uses the same tyre set as the modern RX cars which are probably a good bit better than period rubber. I say probably because Group B was pretty wild, and it wouldn’t surprise me all that much if they were using F1 rubber compounds. It’s a good drive out of the box on the RX tyre set, and great fun to slide around.
So, all told, it’s a chassis that understeers until you push it hard enough, aero that works mostly toward keeping things pointed in the right direction once a slide does start, plenty of power (but only above 6000rpm) with some lag, and a great AWD system that will allow you to plant power on the ground and pull out of corners.
Racing this thing is fantastic once you get the hang of two key aspects: keeping it on power, and learning to use pendulum turns for initiating turn-in.
Renault 5 Maxi Turbo
Ceci n’est pas un rallye. The Maxi was Renault hanging on to an aging format in a time when AWD was clearly the way forward in rallying. Mid-engine, RWD, double wishbone suspension, 60 percent rear weight bias, and 2.5kg/hp may as well be specs from the Renault R.S.01 GT3 car, and this comes through in how it drives.
This car was a tarmac specialist in 1985, and it really is one terrific circuit racer. On the whole, it matches up quite well with the Audi quattro, with the per-track favorite being all down to how much gravel there is. Daytona RX is 85 percent tarmac and gives the Renault a 0.5s advantage per lap; Lohéac flips that and the Audi is a 1s favorite, while circuits such as Hell or DirtFish are more balanced, and the match-up is nearly even.
Like the Audi quattro, there is a great deal of information available about the Renault 5 Maxi Turbo in the form of old homologation papers, as well as enthusiasts who have restored and maintained the cars since their heyday.
The chassis is a very simple design as far as suspension geometry goes, with the measured kingpin and caster values of 15° and 11.5° respectively, giving respectable steering feel especially during opposite lock and powering out of corner situations. Drive comes from the C7K 1,527cc turbo 4-cylinder for 360hp at around 3bar boost absolute through a 5-speed manual and 40 percent lock clutch-and-plate differential on the rear axle. The turbo had a very early anti-lag type of system which recirculated boost airflow to keep it spooled up―but it’s important not to remain off throttle for too long because, once the boost drops, it takes a good few seconds for it to come back on.
The restoration crowd was a big help in having already measured typical wheel rate of the rear springs and torsion bar front suspension. It runs significantly stiffer than the Audi―again, showing its focus on tarmac events―and with a chassis balance that is far more typical of GT cars than cars designed to be pitched sideways into gravel hairpins.
What’s especially telling is the chassis moments of inertia that fall out from our models of the Audi and the Renault. While both the Audi and the Renault feature similar overall dimensions―the Renault is 18 percent lighter than the Audi (900kg vs 1090kg)―the moments of inertia are upwards of 60 percent lower for the Renault! That’s the value of having most of the mass concentrated within the wheelbase; the car is much more eager to turn and respond to steering inputs. Nimble chassis via basic design rather than through modifying a car to make up for deficiencies.
So, all told, it’s a nicer handling car than the Audi, but where the challenge arises is putting power down on the gravel. Power per kilogramme is similar with the Audi, but going to only two tyres means you have to be doubly careful about its application.
This car doesn’t like being tossed around and backed into corners for you to then plant the throttle and power out; that’s far more likely to just end in a spin or the engine bogging down. The quickest way to drive it is by using the brakes to rotate the car into a tight, late apex, and then using just enough power to keep the rotation from stalling, before feeding it back in through the exit with opposite lock to control direction if necessary.
It’s a lot more difficult than the Audi, where anything goes to help fight the natural understeer of its chassis-drivetrain design. The Audi is all about being rough to make it do what you want, while the Renault is about being smooth to take what it will give you. That’s the trade-off to being a tarmac specialist. Loose stuff is pretty tricky, but you can more than make up for its reluctance by treating it like a flyweight GT on any pavement sections―brake super late, smooth fast apex, power down hard through the exit. Sweet little car.
Like the other Group B cars, this one proved great for research as, firstly, there is a ton of interest in the car and, secondly, people who have restored them share tons of old documents and information. Scanning through the original owner’s manual is particularly cool, with a whole section on starting and driving the car written by Jackie Stewart.
This Ford RS200 is a classic example of huge potential which didn’t have a chance to develop. Ford had spent a ton of time developing the front-engine, rear wheel drive Escort RS1700T for Group B, only to throw it all away before entering a race when they realized that they needed an AWD concept to compete against the best. That’s when they began work on the RS200, in mid-1983, well behind the rest of the competition, and using a lot of parts which were left over from then-current projects including the aborted RS1700T car.
The engine is a Cosworth BDT 1.8L turbo 4-cylinder developed for the RS1700T, and it’s a fine engine, producing upward of 440hp@7500rpm with a wide powerband that runs from 5500rpm right up to the rev limiter at 8500rpm. The parts-bin special nature of the early RS200 cars meant it was fairly heavy, though―1,050kg―and this put the engine at the small end of the displacement scale for its weight class. Evolution versions of the BDT-E, had they competed, were enlarged to 2,137cc and people who have since tweaked and tuned them can see upwards of 800hp!
Clever positioning of the 5-speed gearbox meant an even weight distribution of 50:50 (ideal, in theory) and a simple double wishbone suspension controls the chassis well. The AWD system is comprised of three Ferguson viscous limited slip differentials left over from Escort and Sierra projects. No exact rating for these RS200 diffs online or in old books, but we know from the Sierra Group A car that they tended to run in the 100-500Nm range. Standard setup is for 63 percent power to the rear with the viscous center controlling differential slip between the axles. It’s a good configuration for stability, viscous diffs all around, but it does generate a fair amount of understeer.
The legendary New Zealand IMSA racecar driver Steve Millen once said, “It’s quickest to drive the [RS200] into a turn very hard, pitch it in with oversteer and maintain that attitude through the corner with the throttle,” and that definitely works best with this car in-game―it’s a car that takes well to the Scandinavian flick technique, and chassis rotation follows the steering quite directly. Still, it tends to drive a little tight unless you are rough with it; not slow by any means, but less exciting than the Renault and the Audi.
This 1986 version of the car feels like it lands squarely in between the Audi and Renault. It has the mid-engine and tarmac handling of the Renault combined with the AWD traction (and inherent understeer balance) of the Audi. Further development probably would have made the car significantly lighter or more powerful and solved any handling issues to produce a truly strong competitor. But Group B was cancelled at the end of 1986, and the RS200 evolution was binned after just one season.
You can own these machines with the Project CARS 2 Fun Pack.