See how Gordon Murray's iStream Superlight is made
Dunsfold, Surrey - This is the latest version of Gordon Murray’s radical iStream automotive manufacturing system, which uses a high-strength aluminium frame with carbon-fibre outer panels to create a body-shell half the weight of one welded together from dozens of sheet-steel pressings.
And of course, less weight means it uses less fuel, produces fewer emissions and handles better than conventional cars - and it doesn’t rust.
The iStream process actually combines elements of many construction methods, to offer outstanding levels of platform flexibility. As a former Formula one designer, Murray knew when he began working on the concept that the lightest, strongest way to build a body-shell is using a one-piece carbon-fibre moulding (which is why McLaren does it that way) but big carbon-fibre mouldings are very, very expensive to produce and the slightest change in design necessitates a completely new mould.
Modular platform
So he combined a simple thin-wall tubular aluminium frame very similar in concept to those used in modern motorcycles, with honeycomb recycled carbon-composite panels, to create a basic modular platform that can be stretched from a two-seat city car to a full-sized SUV or even a panel van - without the need for expensive press tools or big carbon-fibre moulds (and the huge curing ovens that go with them).
And, to prove that it works, he built the Superlight T.43 chassis you see in the pictures; it’s intended for a mid-rear mounted 165kW engine with a six-speed manual transaxle and independent suspension all round, attached to a subframe under the box-section front structure of the shell and on the engine itself, F1 style, at the rear.
The whole car, he says, would be about 3640mm long on a 2500mm wheelbase, 1750mm wide and 1240mm high, and should weigh less than 850kg wet, giving it a power-to-weight ratio of just under 200kW/ton, which would put it firmly in supercar territory.
Sitting pretty
Then he extended the principle a little further to create the iStream lightweight seat, which uses glass or recycled carbon-fibre composite panels as stressed members on a tubular frame, in a design that’s about 30 percent lighter than a typical vehicle seat, with four-way adjustment and fold-flat mode, that can be tweaked to suit any type of passenger vehicle from a sports car to a minibus, from an aircraft to a train.
On show
Gordon Murray Design will display the iStream Superlight body and lightweight seat at the Low Carbon Vehicle 2018 show on 12 and 13 September 2018 at Millbrook, Bedfordshire.