Rear tire ramps, sidepod extensions and wheel backing plates used together, or in any combination will be optional items for the 1.5-mile ovals, beginning this weekend at Kentucky Speedway.
"The tire ramps and wheel flips should really help so we'll have grip when we are in traffic behind people," said two-time IndyCar Series champion Scott Dixon. "I think those are good options. We are heading in the right direction. One, it gives you more grip and two, it gives you more drag so it's easier to get a draft on somebody or suck up behind them."
Teams will be required to remove half-inch rear wing endfence wickers to provide efficient downforce, remove drag and improve the ability of a trailing car to follow more closely. The optional pieces will give up to an additional 300 pounds of downforce.
"We had numerous conversations with drivers, team engineers and team managers and asked their opinions what needed to be done and these were chosen as the direction based on majority opinion," said Brian Barnhart, the Indy Racing League's president of competition and operations. "We've tried to give teams more options and tools, and they have choices now which downforce level they want to run both in qualifying and in race configuration.
"Some people are going to run more downforce than others, which should make for better overtaking and passing opportunities on the racetrack."
In addition to the aerodynamic performance-related items, Honda Performance Development will introduce brief bursts of additional horsepower and 200 rpms (to 10,500 total) available to drivers through a button on the steering wheel – referred to as an overtake assist button – for the remainder of the season (four ovals, two road courses).
A 5-20 horsepower gain will be realized dependent on fuel setting for intervals calibrated on a race-by-race basis, according to HPD Race Team Manager Roger Griffiths. For Kentucky, drivers will have 20 presses for a duration of 12 seconds each available. HPD will update teams before each race weekend regarding parameters.
"It's to provide the driver, if they're already making a passing maneuver, an additional tool to complete the pass," said Indy Racing League senior technical director Les Mactaggart. "It provides the teams options which they have to choose how they're going to run the race so it brings more strategy from a team aspect."
The system requires a simple ECU software alteration. After each use, there is a 10-second recharge period.
"We hope that the new Honda button feature will add a little spice to the racing; it gives the driver/team an additional tool to use during the course of the race that we believe will promote some additional overtaking with the added complexity in that the feature won't be available until the actual race so teams will have to experiment on the fly," Honda Performance Development IndyCar Series Team Leader Roger Griffiths said.