While Yamaha kept the exterior design of the car a secret prior to today’s launch, Murray revealed that it sits on the radical, all-new carbonfibre structure called iStream Carbon. It’s claimed it “sets new standards for chassis light weighting, rigidity and safety”.
Murray described the technology used to develop the system as a “step change” and said it had the potential to fundamentally change car making.
“Light weighting is the final frontier in the automotive industry fight to lower emissions,” he said. “There have been great strides forward in engine design, electrical control systems, tyre design and transmission technology. But we are now experiencing a plateau in the advance of technology, where the law of diminishing returns comes into play.
“A step change in vehicle weight to enable downsizing of powertrain and components is all we have left in the armoury. Light weighting is important for internal combustion-engined cars but even more important for hybrids and electric vehicles.”
The system is derived from Gordon Murray Design’s iStream manufacturing process, but replaces the glassfibre content with carbonfibre. It has been developed in conjunction with Japanese firm Toray, for whom Murray designed the Teewave sports car in 2011, and sandwiches a honeycomb paper core with two carbonfibre skins.
Murray confirmed that iStream Carbon doesn’t replace the original system. He said: “We are currently working on seven vehicles using our original iStream technology.”
As well as its weight, strength and safety benefits, it is notable for being fast and cheap to produce. Murray claims to have developed a fully mechanised system with a cycle time for each panel of just 100 seconds.
Murray did not disclose the weight of the Yamaha Sports Ride Concept, but it is believed to be significantly lighter than 900kg. The cost of producing a chassis is closely linked to the volume of cars being produced and the up-front investment required, but Murray said the system can be employed profitably for production volumes of between 1000 and 350,000 cars. As such, it is believed the Yamaha Sports Ride Concept could be priced competitively against the likes of the Lotus Elise.
“I genuinely believe this car could open up a new sector,” said Murray. “If you look at the [Mazda] MX-5, it’s great fun and a nice roadster, but it’s not an out-and-out sports car. The Toyota GT86 is great but relatively heavy. It’s not a huge revolution. Then there are cars like the Alfa 4C, which is rear mid-engined but which costs nearly £60,000. I believe we could have something genuinely rule-breaking.”
Asked whether his first confirmed iStream client, TVR, would be using the carbonfibre technology, Murray said: “Because of the secrecy with which it has been developed, the team at TVR haven’t been aware of [iStream Carbon] until now, so it is not part of their plans. But, in time, it is perfectly possible.”
Although neither Murray nor Yamaha would comment on the powertrain in the Sports Ride Concept, it could combine Murray’s chassis with an uprated version of the 1.0-litre three-cylinder engine that was mooted for its city car design, the Yamaha Motiv, which was first shown in Tokyo two years ago.
That engine was tipped to produce 70-80bhp, but uprated beyond 100bhp in an entry-level form, that would be likely to give the car a power-to-weight ratio in excess of 140bhp per tonne, which is around that of an Elise.