Five bits of motorsport tech in your road car

Dual-clutch gearboxes – from the Porsche 956 to the Kia Ceed

There was a time when a fast car had either a manual gearbox or an optional, and usually terrible, automatic. Take the original Honda NSX, for example, which came with a five-speed and later a six-speed manual, and a truly, truly awful four-speed automatic as the alternative. Those days are mostly had long gone, and lower down the automotive food chain conventional automatics are becoming less and less common too – usurped by the double-clutch automatic.

To simplify things vastly, where an old school torque converter automatic uses fluid to transmit the power and torque of the engine to the driven wheels, a double-clutch automatic is a type of automated manual ‘box in which, as the name suggests, there are two clutches, allowing you to drive in one gear with the next gear ready to rumble. The trade-off is often low-speed smoothness – which torque converters have in spades – for shift speed, something double-clutch boxes are renowned for.

The concept of a dual-clutch gearbox dates back to the late 1930s and an engineer called Adolphe Kégresse. It was to be used in the Citroën Traction Avant, but, sadly, Kégresse’s money dried up and the double-clutch wasn’t seen again until the Hillman Minx of the 1960s. That’s right, the Hillman Minx. But Hillman can’t be credited for the now widespread use of dual-clutch gearboxes, but Porsche. Porsche first used a dual-clutch gearbox in the 1980s, dropping a ‘Porsche Doppelkupplungsgetriebe’ or PDK ‘box into a Porsche 956 in 1984. Just two years later a Porsche 962 C won the Monza 360km race with a PDK gearbox.

Fast forward nearly two decades and it was the Volkswagen Golf R32 that became the first road car to use a double-clutch, and since then it has sprung up in supercars like the Ferrari 458 Italia, Porsche 911 GT3 RS, and Bugatti Veyron. At the other end of the scale you can find a double-clutch in a Volkswagen Polo, Kia Ceed and Ford Fiesta, as well as the Volkswagen Golf, and with six, seven, eight, nine and even ten speeds.

Rimac Electric powertrain tech – from electric BMW M3 to global EV brand

Although many car companies around the world are developing electric technologies, the Rimac story is a tremendous one, it really is. Rimac has grown from a one-man-band in a garage in Croatia to one of the big, global electric powertrain and battery players, even if you might not realise it. And it all started because company founder Mate Rimac blew the engine in his race car.

The then 18-year-old Rimac was enjoying a nice weekend on circuit with his BMW E30 M3 when the pistons made a break for the heavens, dumping oil, metal and Mate’s dreams of a good race all over the asphalt. Rather than simply bolting another internal combustion engine into the E30, however, he scoured the internet for parts to build an electric powertrain, and with the bit between his teeth he wanted to prove battery powered cars could be just as fast if not faster than those with petrol or diesel power. Once the electric racer was up and running, as Mate explained to GRR at the beginning of 2020, through trial and error the car became faster and faster until “in 2011 I broke five FIA and Guinness World records in that car”. From then on he started to build other electric components, and not long after he’d started doing that some big car brands started sniffing around to see what Mate could do for them.

Now Rimac builds batteries, drivetrains, driver-assistance systems, connectivity solutions, infotainment systems and other electronics for numerous car brands, and 10 per cent of the company is owned by Porsche. Mate also used some of the money from his early sales to fund his hypercar project, creating the Rimac Concept_One and the C_Two.

Dog ring gearbox – from Abarth race car to Abarth hot hatchback

This is a very, very specific example, but we like it a lot. Every now and then auto makers do something a little bit silly. They crack open a few beers and spend a few late nights at the office, conjuring up plans for fun but more than likely unfeasible ideas that will never see the light of day. Not all that long ago the cheeky engineers at Abarth knocked back a few Peronis and wondered what it would be like to put a racing gearbox into one of their potent but dinky city cars. Somehow, they didn’t just manage it but the men in suits agreed that it would be a brilliant idea to sell it to the public.

The Abarth 695 Biposto is the most extreme Fiat 500-based Abarth road car ever made, and aside from weighing just 997kg, using thicker, more powerful brakes and coming with just two seats, buyers could choose between a normal six-speed manual or a five-speed dog ring gearbox from the Abarth 500 Assetto Corse race car. The price? Just £8,500, a pretty penny on top of the Biposto’s £33,055 list price.

Perhaps this wouldn’t seem so crazy in something like a Ferrari or Lamborghini or even a BMW, in a particularly high-end machine, but in something that is at its most basic level a Fiat 500 we can’t help but remain perpetually surprised this ever happened. And if you can find us another dog-ring ‘box-using road car we’d love to know, because we can’t seem to find another example.

Progressive hydraulic cushions – from Citroën C3 WRC to C4 Cactus

There have been plenty of clever suspension technologies that have filtered down from race to road cars over the years, but one of the more recent, and one of the more interesting, is Citroën’s ‘progressive hydraulic cushions’.

Developed on the Citroën C3 WRC, the system places two hydraulic cushions, one for rebound and one for compression, at the top and bottom of each spring. The springs and dampers do their jobs as usual, but the progressive hydraulic cushions reduce impact forces by transferring the kinetic energy that would normally be sent straight up into the bump stops into heat. How? Well inside these cushions there’s hydraulic fluid, and as it’s compressed it becomes more resistant, gradually reducing suspension travel rather than suddenly ending it.

Having developed the tech for rallying, Citroën thought it would be wasted were it not used in other applications, especially given the company’s experimental and forward-thinking approach to suspension technology. Enter the now sadly departed C4 Cactus, the first car to use progressive hydraulic cushions as part of the ‘Citroën Advanced Comfort’ programme, creating what the company described as a “magic carpet ride”. The C4 Cactus might be dead, and so too is the C3 WRC with Citroën’s departure from the WRC at the end of 2019, but the system lives on in cars the very normal but also very comfy C3 and C5 Aircross.

Carbon-fibre chassis – from McLaren MP4/1 to BMW i3

In the world of Formula 1 there is nothing extraordinary about carbon-fibre. Granted, the way in which it is used in F1 and the strict balance between strength and weight reduction is incredible, but to see a carbon-fibre wing is not in any way surprising. But to see carbon-fibre in a road car? Well that’s a little more common nowadays but, still, relatively uncommon.

Carbon-fibre was first used in Formula 1 in 1981 by McLaren with the MP4/1. With a carbon-fibre monocoque chassis the car was both light and incredibly strong, much stronger than a more normal aluminium and glass-reinforced plastic composite chassis, a design that had been around since Cooper in the 1960s. Over subsequent years carbon-fibre became more and more commonplace, to the point where it began appearing in road cars.

It is the Jaguar XJR-15 than holds the title of ‘first road car with a carbon-fibre chassis’, built from 1990-1992 by TWR in the UK for Jaguar, both as a road car and a racer. The Bugatti EB110 was the second road car to use a carbon-fibre chassis, and the McLaren F1 the third. Today it is McLaren who are the go-to carbon-fibre chassis producers, having constructed every single one of its road cars (with the exception of Bruce McLaren’s M6GT) with a carbon spine. But as is the way with automotive technology, carbon-fibre has trickled down the food chain. Although there’s a lot of carbon-fibre trinketry around, there have been three what could be considered ‘normal’ cars launched over the past decade with carbon constructions, including the Alfa Romeo 4C, the BMW i8 and the all-electric BMW i3.

WRC and McLaren images courtesy of Motorsport Images.