‘but because of concern over the weight distribution for the ovals we’re now looking at opening up an option of a lightweight spool, which could be fitted for the ovals. That would give us another 6.6lb (3kg) or so of weight saving, right where we’d like it.’ Replacing the aluminum
gearbox case with a magnesium unit, and making the bellhousings from the same material, would offer significant further savings (another 6.6lb / 3kg), but the
Below: Xtrac has been paring weight from the aluminium gearbox casing but cost concerns prevent going to a magnesium unit. A lightweight spool may be introduced for oval tracks
costs involved would likely cause an uproar amongst team owners, making it a worst-case option. Engine weights (with the
possible exception of Lotus), including all of the ancillary components involved with forced induction, have also come in a bit heavier than expected, which is perhaps a bigger problem to solve. ‘It gets a little harder as you go forward from the gearbox and bellhousing,’ explained Phillips. ‘We can look at the exhaust and turbos and the systems side of it, but the turbos are very hard to change. And again, for the engine guys, they’re working to a set of regulations so they’ve got their guidelines to stick to. Some of
the initial weight projections for the engines, perhaps over a year ago, were very, very competitive. ‘The people that laid out the
car a year ago expected one thing, but that’s also added to the rear weight distribution [problem].’ Phillips confirmed that
engines from Lotus, Chevrolet and Honda will be required to meet an identical minimum weight, and for those who come in light, ballast will be used in a spec location, yet to be determined. The original minimum weight target for the 2012 powerplants was 220lb (100kg), but that figure has since changed, at the behest of the three marques, though the new figure has been kept private.
SUSPENSION CHANGES Altering the wheelbase of an open-wheel car has been popular practice to affect weight distribution for decades, but the DW12 was designed around a fixed wheelbase of 120in (3048mm). To move the weight distribution number forward, sweeping the DW12’s A-arms back would help to place more weight on the nose, but would entail major alterations to the bodywork, aerodynamics and the mechanical components at the rear. ‘Dallara has looked, but the rear geometry already sweeps the rear wheels back and it might induce issues with excess driveshaft angularity,’ confirms Phillips. ‘They feel that
February 2012 •
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