TECHNICAL UPDATE
Exploiting the aerodynamics
Even within the tight confines of IndyCar, there are still detail differences to be seen By Marshall Pruett
W
hile the current spec of IndyCar conforms to an incredibly tight set of rules, teams are allowed just enough
freedom to experiment with bespoke items like front wing end plates and rear wing mount plates, and to use some of the optional oval package items such as sidepod extensions and rear ‘wheel backers’. Most teams save a special set of ‘Indy
bodywork’ just for the Speedway, which has received weeks of effort to perfect its shape, to fill the smallest gaps and seams and to minimise any areas where air might become blocked or impeded as it travels inside or over the car. Teams also spend a huge amount of time perfecting the angles of the exposed
from the inevitable debris that is thrown rearward at over 200mph. With its origin as a pliable tape used
to protect the delicate leading edges of helicopter rotor blades, motor racing is a perfect alternate use for the product. But at upwards of $300 (£185) per roll for the highest grade of tape, it is a high consumption item, especially at Indy when it is used every day by every team. At the front of the spec Dallara chassis,
front wing end plates provide the biggest opportunity for teams to produce their own solutions. Most teams simply chose to run with the stock end plates provided by Dallara, but some, like Target Chip Ganassi Racing, have developed their own. While the aero gains may only be minimal, finding an improvement of a few hundredths of a second around Indianapolis makes the time
“finding a few hundredths of a second around Indianapolois makes the time and expenditure here well worth the effort”
suspension items, spending time testing up and down long airport runways or automotive proving grounds, doing nothing other than rotating steering arms and sidepod mounting struts in minute increments to find the most aero-friendly angle to use on the super speedways. For the sections of the body where transitions happen – where the front wings meet the nose, where the radiator blocking panels meet the sidepod and where the front suspension mounts to the chassis – teams use thin and rubbery ‘helicopter tape’ to smooth airflow and reduce drag. In its thinnest form – about 3mm thick – helicopter tape also helps minimise damage to an IndyCar’s carbon fibre body
and expenditure here well worth the effort. The front wing end plates are designed to match the wing angle range a team expects to run, which gives a further indication why different teams might choose to produce their own solutions.
Gurney flaps are also open to
interpretation, and everything from carbon fibre to old school aluminum Gurneys can be seen up and down the pit lane, in varying size and height. Some teams prefer to use Gurneys with a uniform height, while others opt for ones that are flush in some areas and stand tall in others. The Dallara’s rear wing section is also
a place where many detail differences can be found, but those variances are found
Front wing end plates are open to development by individual teams and generally match the wing angle range a team expects to run
www.racecarengineering.com • August 2011 71
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