First Day of Aero Kits Bring Intrigue, But Look For Much More
May 06, 2015 | By Marshall Pruett, Special to IMS.com
One of the most anticipated days leading up to the 99th Running of the Indianapolis 500 took place on Sunday, and once the first outing for superspeedway aero kits was complete, open-wheel fans had a glimpse into the bodywork changes that could give Chevrolet or Honda the upper hand.
Two unique approaches to Speedway aero kit design were on display as both brands turned their first laps at the Indianapolis Motor Speedway during a day-long data gathering exercise, and when it was over, the proud manufacturers demonstrated how close the battle for “500” supremacy will be.
The one-day test gave teams and drivers just enough time to get a feel for the differences between the stock Dallara bodywork that Dario Franchitti, Tony Kanaan, and Ryan Hunter-Reay used on their way to Victory Lane from 2012-14, but with a number of variables to deal with, extensive running was a challenge for almost everyone.
Team Penske’s Juan Montoya was the fastest driver on Sunday, using a tow to post a lap at 226.772 mph, and as the 2000 Indy 500 winner said today, the field needs more time to get the most from the custom aero kits.
“I think it was a good day to get a feel for what they’re like, but there wasn’t enough time to really work through a bunch of big changes -- that’s what we have a week of practice for, so I think you’ll see speeds come up more when we start running after the Grand Prix on Saturday,” he said. “We all did our programs, we all learned a lot, but there’s a lot more to come.”
Those lessons will take place over many days next week as teams try an assortment of aero kit options as they search for the best Race Day and qualifying setups. Between the two kits, the front of a Chevy and a Honda look rather similar, while the sidepods and the rear of both cars provide the most pronounced visual differences.
Aero kit regulations allowed the manufacturers to design their own front and rear wings for the first time, and when viewed from a slightly elevated perspective, the Chevy’s front wings are unique in their rounded trailing edge. The Honda’s front wings are perfectly straight – rectangular -- by comparison. Front wing endplates are also different between the brands, with Chevy using innovative and adjustable units, while Honda has opted for traditional fixed endplates.
IndyCar mandated the use of a wicker that runs down the center of the chassis that helps stability in the event of a spin -- similar in concept to NASCAR’s roof flaps -- and those strips are required on all cars going forward. Moving out to the sidepods, Chevy’s bodywork looks small and shrink wrapped, and in a carryover from its road course kit, its designers continue to use an opening that allows air to flow between the sidepod and rear tires.
Honda’s sidepods are distinguished by the unbroken ramp-like progression that builds from the radiator inlets to the bulges that shroud the rear tires. The engine covers are unchanged from their respective road course kits, but everything else at the back of their cars has been tailored for optimal performance at Indianapolis.
The most dramatic look across the Chevy and Honda aero kits -- at least at the start of the Month of May -- belongs to the Japanese brand, thanks to its adventurous rear wing arrangement. With a variety of cars on track, the easiest way to tell a Chevy and Honda apart comes from looking at the rear wings, and with Honda using a pair of wing extensions on both sides of the rear main plane, the sheer width of its three-piece rear wing array is striking. Chevy, which is rumored to have a similar solution waiting in the wings for qualifying, saw its cars test on Sunday using a single rear wing element.
Designs for both rear wing solutions are impossibly small and thin, and while the Honda unit makes use of endplates to cap its main plane, the Chevy currently runs without them. The final point of note between rear wing designs involves the mounting methods. Honda, which pioneered the top-mount “swan neck” system in 2009, has incorporated it into its Indy car aero kit. Chevy has chosen the familiar bottom-mount method. Even if the Chevys start to run the wide Honda-style rear wing extensions, you’ll be able to tell one brand from the other by the presence (or lack) of wing mounts on the top of the rear element.
The final item of note involves the rear wheel guards, which have taken on smoother profiles to improve the clean flow of air as it departs the cars.
Despite the extreme departures found from front to back, Montoya’s fast lap in his Team Penske Chevy was just 0.504 mph faster than Marco Andretti’s best in his Andretti Autosport Honda. Without the benefit of a tow, the gap was slightly larger, but with so much left to learn by both camps, conclusive results will remain a mystery until thousands of laps have been turned.
“I think we have something that’s pretty exciting and maybe nerve-racking,” said defending Indy 500 winner Ryan Hunter-Reay. “We’re just scratching the surface of these aero kits at the Speedway. It’s hard to know who has the edge right now, or even who’ll be the fastest in qualifying. And the race … I won’t even hazard a guess because we’re going to learn so much between now and then. There’s a big sense of going into the unknown for all the teams right now. I don’t think we’re going to have an idea of who’s going to have the package to beat until we get to those crazy final laps, and if I’m right, it should be fun to watch.”
The last few years at Indy have been all about the engines, but with aero kits throwing a curveball at the Field of 33, every day of running will unlock more speed secrets.