INDIANAPOLIS — A day after Porsche swept the top two times during the opening day of the two-day IMSA WeatherTech SportsCar Championship test at the Indianapolis Motor Speedway, the BMW duo from Team RLL went 1-2 on a sun filled Saturday around the 2.439-mile road course layout.

Connor De Phillippi set quick time in the final of the two sessions with a lap of 1:14.655-seconds in the No. 25 BMW M Hybrid V8.

Ironically enough, the top two times came from the same three drivers splitting the pair of RLL cars. De Phillippi, Jesse Krohn and Colton Herta shared both the No. 24 and No. 25 entries with Krohn piloting the second quickest time (1:14.758-seconds) for test in the No. 25 ride on Saturday afternoon.

It was a massive improvement from the team in gaining seventh-tenths overnight between Friday and Saturday with top lap from Friday on the 24 car being 1:15.498-seconds and the 25 car at 1:15.769-seconds.

“It was good today,” De Phillippi said. “We worked on a lot of different areas of the car, made some good steps on the systems side, understanding a few of the areas I feel like we’ve been weak on. So, I feel like we have a better understanding of the direction we need to go.

“I don’t think we have it totally figured out, but at least we have a direction. Really proud of the team. It was a productive two days.”

Wildly enough, it was a complete flip-flop kind of day from the rival German camp from Porsche. They went from 1-2 on Friday to the bottom two on Saturday.

The No. 5 JDC Miller Motorsports Porsche 963 went faster on Saturday (1:15.181-seconds) compared to Friday (1:15.498-seconds) but fell from the top to the bottom in being second to last among the GTP cars in 7th.

The No. 6 Porsche Penske Motorsports entry driven by Nick Tandy and Mathieu Jaminet was last among the top class at 1:15.181-seconds. They were 6th on Friday but at 1:15.655-seconds. While gaining five-tenths, they were still last.

The team car that was P2 on Friday was P5 on Saturday in the No. 7 Porsche Penske Motorsports entry that was driven by Matt Campbell of Australia and Felipe Nasr of Brazil. They were P3 in the morning session.

P3 in the second session and third fastest of the test belonged to Four-time INDYCAR SERIES champion Sebastien Bourdais who was third quickest overall Saturday at 1:14.809 in the No. 01 Cadillac Racing Cadillac V-LMDh fielded by NTT INDYCAR SERIES championship winners Chip Ganassi Racing.

They led the way in the morning session at 1:15.025-seconds and were fifth on Friday.

“Obviously it’s great to be back here at the speedway,” Bourdais said. “It’s going to be a great event for IMSA and something that everybody wants to be part of. Indianapolis is a great motor racing town and it was very much desired by the crowd to put something together here.”

While this wasn’t the first time that he’s turned laps around here in a sports car, this was the first time that he’s done so in 10 years. The last time was with the old F1 style road course to where they used all of the south end oval to scream down the front stretch clockwise.

This time, he’s in a GTP car on a somewhat different layout for which he said that didn’t take him much time to get used to it.

Bourdais and van der Zande turned 71 laps around the famed track on Friday and 124 more on Saturday.

Bourdais said that one of the difficulties between an IMSA car here and an Indy Car is that you don’t have the braking and downforce levels that the open wheel car has. You have to brake much further back in order to get the car now slowed down enough to make the corners.

“It’s a very different era for the cars,” Bourdais told a group of reporters on the fourth floor of the IMS Media Center between sessions on Friday. “The biggest difference is actually the layout of the track. I actually really liked that track (the old layout), but this one is a completely different challenge, but the feel is quite similar.”

Bourdais is hopeful to become the first winner back here since the inaugural sports car race back in 2012. He led 24 laps that day.

“Everybody wants to kiss the bricks, right?” he said.

Points leaders Pipo Derani and Alexander Sims were P3 in their No. 31 Whelen Engineering Cadillac V-LMDh on Friday and P6 (1:15.039-seconds) on Saturday. They were P2 on Saturday morning.

In the Le Mans Prototype 2 (LMP3) class, Mikkel Jensen was quickest at 1:16.532 in the No. 11 TDS Racing ORECA prototype. Matthew Bell led the Le Mans Prototype 3 (LMP3) class for the second straight day, stopping the clocks at 1:21.209 in the No. 13 AWA machine, an improvement over his best lap of 1:21.401 on Friday.

The sole GT Daytona Pro (GTD Pro) team that tested Friday, Vasser Sullivan Racing, didn’t turn any laps Saturday. Misha Goikhberg led the GT Daytona (GTD) class at 1:24.192 in the No. 78 Forte Racing Powered by USRT Lamborghini Huracan GT3 EVO2, the quickest lap over both days for the class.

All five classes will compete simultaneously during the TireRack.com Battle on the Bricks, with the nearly 10-second gap in lap times between the GTP and GTD cars ensuring plenty of action and drama as quicker prototypes navigate lapped traffic of the production-appearing GTD classes.

Bourdais says that’s going to make this September’s race a tricky, yet thrilling one. With so many cars around here, there’s going to be traffic and going to be plenty of times with that gap in a speed differential to have the GTP cars catching the others. However, you can’t just pass as easily as you’d like and if you catch a slower car in the wrong place, it could be a massive loss of time which could make for a race to where no one is going to get too far ahead.

Plus, the braking zones here will make for a lot of moves too.

While Friday saw temps soar into the 90s with a heat index pushing 100 and Saturday in mid 80s again, conditions could be far different when they’re back in a couple of months. In saying that, Bourdais said the tire fall off is pretty big and that in traffic in what should be cooler conditions, simulating tire fall off in the heat could in directly translate over to data that they could use.

In testing for the Michelin Pilot Challenge series, which showcases the latest high-performance production sports cars, coupes, hatchbacks and sedans, Eric Filgueiras was quickest in the Grand Sport (GS) class with a lap of 1:30.680 in the No. 28 RS1 Porsche 718 GT4 RS CS. That time, set during the first session Saturday, was considerably quicker than the top GS lap Friday of 1:31.865 by Eric Foss in the No. 56 Mercedes-AMG GT GT4 of Murillo Racing.

The No. 33 Hyundai Elantra N fielded by Bryan Herta Autosport with Curb-Agajanian remained atop the Touring Car Racing (TCR) class, but this time Harry Gottsacker was the quickest driver. Gottsacker’s time of 1:32.388 during the second session topped the best Friday time in the class of 1:33.315 set by his teammate and co-driver, NTT INDYCAR SERIES and Indianapolis 500 veteran Robert Wickens.

IMSA WeatherTech SportsCar Championship teams and drivers tested in order to prepare for the return of the series to IMS for the first time since 2014 at the TireRack.com Battle on the Bricks on Sept. 15-17.