Racecar Engineering and, with the prototype breaking cover on 1 March 2012 in California, its creator explained the challenges that were faced with bringing the car to reality. ‘When the ACO were seriously considering us being Garage 56 they were concerned about safety, of course,’ said Bowlby. ‘And one of the things
B
en Bowlby’s
DeltaWing design was chronicled at the concept and design phase in
they said was, “Could you use a conventional LMP1 chassis? Does that fit with the concept?” I said, of course we can use a standard chassis. They said that would ease passing current FIA impact tests, so we looked at whether we could do a closed cockpit car and the drag advantage or whether to do an open cockpit car. And basically, George Howard-Chappell offered the AMR-One for sale. ‘They were geared up, had
spares and theirs is an open cockpit, which is very good as it doesn’t get as much lift on the top surface when you spin the car around 90 degrees. We decided with the weight advantages and reduction in complexity, an open cockpit car
would be a wise choice for us. And it was a way to shortcut the programme too, because we had to do the entire design and get a car on the ground, and we did that in exactly seven months. I don’t think we would have finished the car in the time otherwise.’ With a primary and spare AMR-One chassis at Dan Gurney’s All American Racers (AAR) southern California base, one of the unique solutions for the DeltaWing was finalised. The original plans had called for a bespoke chassis penned by Bowlby but, with the Aston Martin tub, there was a need to design and attach a new front suspension and steering sub-chassis to the AMR-One’s
forward bulkhead. Rather than just graft on the AAR-built composite piece, the team came up with a novel but simple attachment: ‘There are four studs on quick release cams, two on each side, and a coupling that has a carbon composite piece mounted on the front, where a normal crash box would have been, except ours carries the whole front suspension. Beyond it is another new impact structure, a crash nose.’ With the featherweight front section in mind, Bowlby says torsional rigidity was never a concern. ‘The three-point layout of the DeltaWing has 97 per cent of its business at the rear. Therefore, for cornering, the torsional impact of the influence of the chassis is virtually zero. There is no lateral load distribution transfer due to the chassis stiffness. And we were so exceptionally stiff, compared to what we needed, that we didn’t even question it. That is the truth – the DeltaWing does not need enormous torsional stiffness to make it a viable deal for handling characteristics.’ Although the AMR-One
chassis complied with crash test regulations, Bowlby’s small, light front suspension module is required to undergo impact tests of its own. ‘I met with the FIA and we
worked out that the car’s total weight, full of fuel and with the driver aboard, is 575kg. So we had to do the normal 14m/ sec, full 575K crash test and maintain the 25g average. ‘We’ve been working on
“an affordable solution for those who want LMP1
performance with the simplicity of a Formula Ford”
those crash tests at a facility in Indy and they’ve been kind enough to lighten their crash rig so we can get down to minimum weight. In fact, we discovered there wasn’t one [rig] in the world that was light enough for us to achieve the correct total mass because, by the time you strap the chassis on and the driver, fuel and all the rest of it, it always weighs more than 575kg. One of the most noticeable changes from the display version of the DeltaWing is
May 2012 •
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