Power boost raises the bar for Indy qualifying speeds

Image by Scott LePage/LAT

Power boost raises the bar for Indy qualifying speeds

IndyCar

Power boost raises the bar for Indy qualifying speeds

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Fast Friday and the lone weekend of qualifying for the Indianapolis 500 will see a new spike in power with the addition of 45hp to the engines produced by Chevy and Honda.

The extra 45hp will come from an increase in turbocharger boost. Teams race with 18.9psi of boost (130kPa) fed to their Borg-Warner turbos, and for most of the 2.2-liter twin-turbo V6 era, IndyCar has granted a temporary increase to 20.3psi for qualifying (140kPa), which has added approximately 45hp to the motors, and resulted in a leap in both top and average speed.

The new plan coming in May eliminates the mid-tier 20.3psi/140kPa setting from the rules, and takes the boost figure up to 21.8psi (150kPa) to deliver another 45hp, which will serve as a new bar for power used at Indianapolis since the current turbo formula came into play in 2012.

The 21.8psi/150kPa figure is used at road and street courses, and short ovals, where both manufacturers have an extensive amount of tuning knowledge to apply towards Indy 500 time trials. The lower 18.9psi/130kPa level is only used during the Indy 500 and the series’ visit to the 1.5-mile Texas Motor Speedway oval.

“It’s a pretty big change,” Chevy Racing IndyCar program manager Rob Buckner told RACER. “Both us and our competitors spent a lot of time on our dynos trying to find Indy 500 qualifying performance at a boost level that was somewhat unique for the event. With the new boost target, it simplifies planning and calibration efforts because it’s a level we’re very familiar with using.”

Pole position for the 2019 Indy 500, set by eventual race winner Simon Pagenaud from Team Penske, was a four-lap average of 229.992mph, with a peak trap speed of 238.537mph recorded on entry to Turn 3. The modern standard, set in 2017 by Chip Ganassi Racing’s Scott Dixon in optimal weather conditions, was a pole-winning average of 232.164mph with a peak trap speed of 238.955.

The effect of aeroscreens on Indy speeds remains an x factor. Image by Barry Cantrell/LAT

The only mitigating factor that could keep the 2019 speeds from climbing appreciably is the inclusion of IndyCar’s new aeroscreen driver safety device, which adds 58 pounds to the cars and more aerodynamic drag for the engines to combat.

In dealing with a heavier car to accelerate and push through the air, the majority of the 45hp increase will be absorbed by overcoming the aeroscreen’s mass and shape.

“We’ve had the 140kPa the last many years to get the speeds up in qualifying, but with the aeroscreen, there could be a 1-2mph speed reduction with the drag and weight it brings, so Honda, Chevy, and IndyCar all decided to go to 150kPa to ensure we don’t lose any speed,” said Allen Miller, Honda Performance Development’s race team leader. “The simulations we’ve done suggest it could be a pretty neutral change, so an average of 230mph or over could be possible. Our expectation is we’ll, at minimum, go as fast as we’ve gone recently. And maybe a little bit faster.”

Buckner shares in his rival’s anticipation of slightly quicker qualifying speeds.

“I think everyone’s excited about more power,” he added. “It also offsets the addition of the aeroscreen. Our drivers have not complained at any time when there’s a bump in performance, and I think with the right wind directions, you could see a 240mph top speed. At COTA, I know we had some challenging conditions, but we saw the lap times were competitive with the aeroscreens. I think we’ll all find out together where we stand with speeds when we run the Indy Open Test at the end of April. I wouldn’t be surprised if we see some big numbers in May. I think it’s a win-win.”

 

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