With most performance cars, the accepted mid-engined layout is something of a technical challenge. It has promoted some odd attempts at packaging, and some have grown tired of the format altogether and opted for a different layout with a few gizmos to try and replicate that wonderful handling balance. The bright minds at Popular Mechanics recently identified some of the strangest drivetrains out there — let’s take a more studious look at some of the stand-outs.
Perhaps the least obvious mid-engined oddities is Ford’s short-lived RS200, a car designed to compete in Group B rally but due to politics, never got a chance to shine. Nevertheless, its approach to the mid-engine format is odd, eccentric, and in a strange way, very alluring.
When it comes to strange drivetrains, bordering on the needlessly complex, the RS200 has to fall in there somewhere. Because the RS200 was so small, it had to fill those fenders very carefully, with a four-cylinder, turbocharged motor sitting behind the driver’s compartment and four wheel-drive, there was plenty of room to shoehorn into that chassis. What makes the RS200 unique is its gearbox positioning.
Whereas most mid-engined cars have their gearbox mounted behind the engine, this car has it mounted in front to improve balance. This would transfer torque to the center differential, which would then distribute torque with a specific driveshaft for each axle. Additionally, the center differential was capable of distributing torque in three different ratios: 37:63, 50:50 or 0:100, depending on the terrain and traction available. Considering how small the RS200 was — just 157.5″ long — it’s hard to consider how much tech went into this petite package.
More conventional, but equally strange was the drivetrain found in Nissan’s Skyline GT-R. At the onset of the early nineties, four wheel-drive was becoming a very vogue asset to equip a supercar with, and the Japanese manufacturers jumped on this. Perhaps it was Nissan who best utilized this layout, however, because their system was one of the first that constantly varied torque from the front to rear axle based on the traction available and the vehicle behavior.
Known as ATTESA-ETS, this intelligent four wheel-drive was one of the first to have totally variable torque distribution, which functioned predominantly like a rear wheel-drive tranny until wheelspin or slip was registered, and then sent torque to the front axle via a short driveshaft connected to a transfer case hanging off the bellhousing. Inside the transfer case, a series of wet clutches sent power through a clutch pack center differential, which allocates the power front and rear.
That distribution is done through an oil pump that feeds oil into the transfer case, and the higher the oil pressure, the more locking from the clutch pack. Using a 16-bit processor, the car’s ABS sensors observe each wheel 100 times per second to determine whether wheelspin is occurring, and if so, allocates the right amount of torque — up to 50% — to the front wheels to remedy the problem. Generally speaking, when the car senses throttle-induced oversteer, it can shift torque forward in several milliseconds to improve traction, which minimizes the understeer present in a full-time AWD system with the stability of said system. In terms of everyday performance, the GT-R moved the game forward dramatically, and throughout the 1990s, it became one of the benchmarks automakers sought to best.
Front-engined, four wheel-drive might seem fairly common by today’s standards, but it was still uncharted territory in the early nineties. Around that period, Ferrari sought to introduce a new flagship with an F1-inspired design to replace the F40. The F50 was quite revolutionary in one specific way: the drivetrain became a stressed member of the chassis. When it comes to mounting an engine into a production car, automakers typically use soft bushings to dampen some of the vibration from the running gear. However, the F50 had its drivetrain mounted directly to the carbon tub! Such was the rigidity offered by this setup that the rear suspension was supported by the engine and transmission.
While this is common in purpose-built racing cars to improve rigidity and reduce weight, a lack of bushings can make life a little unpleasant while cruising down the boulevard. Even some GT racing cars use solid bushings or a spaceframe rather than opt for this extreme method. However, the F50 was advertised as an F1 car for the road, and that it certainly was — warts and all. However, it’s not certain whether the occupants, who had paid an enormous amount of money for this exclusive halo car, enjoyed the fillings rattled out of their teeth.
The ways in which drivetrains are implemented into cars has been pretty well streamlined these days, with tried-and-true examples dominating the scene and seldom room given for quirky innovation. This is typically most effective or efficient, but in some ways, lacking in style. Innovation is what made these cars so intriguing, and while they’ve been deemed outdated, still hold onto some of their quirky charm many petrolheads wished modern cars more often possessed.