Where Road America's new speed is coming from - by the numbers

Road America’s brand-new track surface has helped NTT IndyCar Series teams to carve almost four seconds from last year’s best lap times, but where are the biggest gains in speed and greatest reductions in elapsed times taking place between the 14 turns?

Thanks to the help of one of the series’ leading teams, RACER has the answers and some of the findings are remarkable.

Image by Road America

Comparing apex speeds at Turn 1 from 2022 to 2023, a stunning increase of 9mph has been generated, which also speaks to the grip available in Turn 14 to launch drivers up the long straight past the start/finish line. If arriving at Turn 1 with an extra 9mph wasn’t enough of a boost, the shedding of time between the apex of Turn 1 and down the hill to Turn 3 has been in the 0.5s range, which is a big contributor to the steep drop in lap time.

At Turn 3, the speed increase was more modest at 2.2mph, and with a headwind to deal with, the ET reduction between Turns 3 and 5 was a modest 0.25s. Apex speed at Turn 5 was up 5.6mph over 2022, and in the short blast up the hill and under the bridge to the apex of Turn 6, 0.4s was pared from the lap.

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At Turn 6, cornering speed was 2.8mph higher than last year, and the ET racing from the apex of Turn 6 to Turn 7 was 0.2s faster. Turn 7 saw a speed hike of 3.6mph with a negligible ET improvement on the run to Turn 8, but once again, a steep rise in speed was recorded with an extra 4.4mph found at the apex of Turn 8.

The third-highest hike in speed throughout the 4.0-mile course was found in the Turns 9 and 10 complex known as the Carousel as a full 8.7mph spike was produced and 0.45s was carved from the lap between the Carousel and the Kink at Turn 11. Facing a headwind, there wasn’t much to be gained for speed at the Kink—just 0.5mph—but that will likely change in qualifying.

Despite the modest increase at the Kink, the apex of Turn 12—Canada Corner—was visited with 5.4mph more speed than last year, and that speed was used to slice 0.3s from the lap on the way up to Turn 13. Carrying that momentum on the new surface, the wildest jump in speed from 2022 was captured with 9.8mph laid down at the apex of Turn 13.

Braking for Turn 14 shed some of that 9.8mph, but not much, as 6.9mph was carried across the apex and up the final hill to close the lap. In that shot from Turn 14 to the finish line, 0.6s was shaved from the tour around Road America.

And to close, the Carousel -- site of the highest cornering loads -- produced an increase from 3.0 lateral Gs last year to 3.4 in 2023, and for some drivers in qualifying who err towards a higher downforce setup, the Carousel should be flat. For those who elect to run a lighter downforce package to exploit speeds on the many straights, the Carousel will likely require a lift, but by the time the session is over, the top teams could be flirting with setting a new lap record to eclipse Dario Franchitti’s 1m39.866s lap from 2000.

Alexander Rossi’s best from the second practice session, held two hours before qualifying, was a 1m40.9112 set on Firestone’s slower alternate tires…