There’ll never be a clear cut answer as to which form of drivetrain configuration is superior. It all depends on the application (what you want the car to do) and driver preference.
No doubt about it; if you want the fastest way possible of going around a circuit on a dry surface then the lightweight, mid-engined, rear-wheel drive option is the way to go.
In this configuration, you’d want the car to be:
- as light as possible
- with the majority of the mass concentrated between the two axles (and as low-down as possible)
- with a powerful engine for a great power to weight ratio
- fitted with the widest, grippiest rubber that is practical
- and the most effective brakes possible.
A Formula 1 car (and a car like the Caparo T1) exhibits all of these vital attributes and one can’t find any quicker way of lapping a circuit than in a Formula 1 car.
A Formula 1 car is the pinnacle of performance, attaining maximum G’s not only in lateral acceleration but also forward acceleration and braking deceleration. The latter is said to be eye-poppingly stupendous. One of the reasons a Formula 1 car is so fast around a circuit is because of its amazing ability to brake as late and as hard as possible from such enormous speeds. Cars with this configuration are designed to extract maximum performance within the envelope of maintaining grip. It’s a knife-edge balancing act.
Cars like WRC racers and their road-rally kin are designed to operate in an environment where grip is often lost and the balance of the car is compromised as a result. In order to address this requirement modern rally cars from circa the original Audi Quattro have made extensive use of all-wheel drive traction to adjust the vehicle’s angle of attack once grip is lost. Pitch the car into a corner using a Swedish turn or hand-brake, turn-in resulting in oversteer and get back on the gas using the maximum tractive force available to pull you out of a corner. The variation in surface grip, texture and moisture content means that a rally car has to be very adaptable to suit the prevailing conditions. Rally cars are in fact quite at home and still massively quick on tarmac.
A Formula 1 car, I hear, isn’t too hot on a muddy dirt road…
So yes, pinnacle cars like the Carrera GT, McLaren F1, Pagani Zonda and Ferrari Enzo all exhibit the characteristics needed to be as fast on tarmac as possible. And just look at how the Carrera GT performs! It’s arguably the fastest supercar round the Nurburgring and, according to EVO it’s also the fastest supercar around Bedford too… Cars like the Ariel Atom and Caterham 260 are more track-day racers than out and out kings of the road.
What is important about those Bedford Autodrome lap times is that they paint a very clear and unbiased view of exactly how various models of varying configuration stack up against each other. Here, we can see that, in certain instances AWD is no disadvantage. Take the humble Subaru Impreza WRX STI for instance. Not very pretty, not very fast at the top-end and yet it posts an identical time to the 373 kW BMW M6. An EVO IX FQ-340 pulverises the Scoob. The STI, here in 206 kW, 2.5 litre guise, it has to be said is one of softest STI’s in memory – obviously it’s been optimised for road use and American preference for a slightly softer ride. A 235 kW 2.0 twin-scroll turbo STI Spec C Type RA-R (yes really – this does prove that the Japanese to have a sense of humour) would be much much quicker.
The only cars that would eclipse this Japanese duo are the truly spectacular supercar league. A similarly configured RS4 is significantly off the pace but still quicker than any of its direct competitors. Weight, clearly is a very large factor when it comes to cornering prowess.
So, who says all-wheel drive is slow? Y’see what all-wheel drive does for cars like the STI’s and RS4’s of this world is amazing, but what it does for cars like the BMW X5, Porsche Cayenne Turbo and Subaru Forester is just downright miraculous. Here are cars with the odds loaded against them… They have high centre of gravities, high mass and less than perfect front to rear weight distribution. And yet, they corner with amazing prowess for what they are. This is directly attributable to all-wheel drive and some clever limited slip differential technology that primarily guides torque to the front and rear axles as required.
In the wet, of course, simple physics and a rudimentary appreciation of grip co-efficients show that all-wheel drive cars are in a league of their own; hence the term coined: devastating all weather capability.
I love cars like the BMW M3, Ferrari F430 and Porsche GT3 for the purists motoring experience they provide. But I voted AWD because I have a sound understanding and experience of the benefits of AWD in real-world motoring conditions. The key here is to understand how they work, learn to react correctly once the limit has been overstepped and then have an absolute blast exploiting the amazing adjustability of cars like the STI and EVO IX. All for a fraction of the price of similarly capable machinery.
Very nice topic IE. And yes, on another day I might've voted the other way round - it's just not cut and dried.