INDYCAR vice president Will Phillips believes the Dallara DW12 is up to task on ovals after a two-day wind tunnel test last week.
Questions about the chassis arose during a November test session at the Indianapolis Motor Speedway, when it only achieved an average lap speed of 215.6mph on the 2.5mile oval. A Target Chip Ganassi Racing IR11 chassis in qualification trim recorded an average 227.34mph in May.
This caused a hastily arranged rolling test by INDYCAR and Dallara in North Carolina to see what more could be done to increase aerodynamic performance.
“We then compared the 2012 car as it was run at its fastest during the (November) testing at the Speedway,” Phillips said. “We showed that aerodynamically the car was limited to 218.4 mph, so the (drivers/teams) did a good job of reaching its potential. We then compared the production car, which is slightly different from the prototype in terms of different mirrors, different rear wheel fairings, subtle differences in chassis construction and better integration of the Zylon (side intrusion) panels.
“Basically, the production car is more slippery (moves the air better) than the prototype. That lifted the speed as the car was run. We then looked at how could we improve the aerodynamic force of the car. Basically, by optimizing the aero set-up, re-balancing the car and then putting on some aero development parts, it showed that using a nominal assumed horsepower of 575 the car is capable of 225 mph.”
Fifteen IZOD IndyCar Series teams picked up their first DW12 chassis in December, with a further seventeen teams having theirs delivered earlier this month. Engine manufactures Chevrolet, Honda and Lotus tested their DW12′s at Sebring a week ago as they continue developing the car before the season opener in St. Petersburg in March.
“Same test at same venue using an '11 car and '12 car, and that's the only data we're using to compare,” Phillips said. “It's about as clean as we can make it for a two-day test.”
With the introduction of multiple ‘aero kits’ in 2013, the potential of higher speeds will be an item for INDYCAR officials to address.
“As we look at aero kits for 2013, the car could be exceeding expectations as they reduce drag further,” Phillips said. “But it's not always about aerodynamics. You have to mechanically set the car up to drive it, so it's always a balance. Aerodynamically, we've proven that it can happen but we haven't proven mechanically that we can set the car up to go that speed yet.”