What makes IMSA sports car racing cool? The cars look very cool, of course, and the mix of classes all racing at the same time makes for exciting stuff.

But most importantly is the sound, or the mix of sounds. From growling, normally aspirated V8s to high-revving inlines with Porsche flat 6s and turbo-hybrids in between, it’s an intoxicating blend.

It allows one to, say, identify cars when all you can see is the headlights streaking through the trees as you stumble drunkenly through the thick forest along the Mulsanne Straight at Le Mans at 3:00am…..not that anyone I know would do such a thing…..

So as IMSA sports car racing returns to the Indianapolis Motor Speedway for the first time in nine years with the TireRack.com Battle on the Bricks this weekend, it’s a motorsports spectacle that even a blind person can enjoy

All five IMSA WeatherTech SportsCar Championship classes will be in action on the 14-turn, 2.439-mile road course. The race is the penultimate event of the 2023 season as well as the finale to decide the IMSA WeatherTech Sprint Cup title in the GT Daytona (GTD) class.

Forty-eight cars are entered across the five classes for this return to one of the most storied venues in motorsports. The two-hour, 40-minute race will be broadcast live on NBC starting at 1 p.m. ET Sunday, Sept. 17.

Other series, including Lamborghini Trofeo, Michelin Challenge and Porsche Carrera Cup will also race in a jam-packed weekend of action.

The teams tested at Indy in late July with mixed results. One day after Porsche led the first two sessions of the International Motor Sports Association (IMSA) Open Test on the Indianapolis Motor Speedway road course, it was time for its German rival BMW to show some speed after sending it over the edge in the first day (featured photo at the top of this article.

Connor De Phillippi led a 1-2 performance by BMW M Team RLL – fielded by NTT INDYCAR SERIES race winners Rahal Letterman Lanigan Racing – in the last two sessions of the two-day test on the 14-turn, 2.439-mile road course. Former Star Mazda (now USF Pro 2000) driver De Phillippi’s best lap was 1 minute, 14.655 seconds in RLL’s No. 25 BMW M Hybrid V8 that competes in the Grand Touring Prototype (GTP) class of the IMSA WeatherTech SportsCar Championship.

De Phillippi, Jesse Krohn and NTT INDYCAR SERIES star Colton Herta shared the team’s No. 24 and No. 25 cars and found speed in both prototype machines. Krohn turned the second-quickest lap overall Saturday, 1:14.758, in the No. 24 car.

Both those laps were quicker than the top time recorded in two sessions Friday, a 1:15.244 by Tijmen van der Helm in the No. 5 JDC Miller Motorsports Porsche 963. The RLL BMW team made big improvements Saturday, as its quickest time Friday was 1:15.498 by De Phillippi, more than seven-tenths of a second slower than Saturday.

“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.”

Four-time INDYCAR SERIES champion Sebastien Bourdais 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.

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.

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.

A familiar name to NTT INDYCAR SERIES fans led the Touring Car Racing (TCR) class, as series and Indianapolis 500 veteran Robert Wickens was quickest overall at 1:33.315 in the No. 33 Hyundai Elantra on the first day. The team owned by INDYCAR SERIES veteran and current Andretti Autosport strategist Bryan Herta also was second on the TCR time sheets, with Mark Wilkins and Mason Filippi at 1:33.634 in the team’s No. 98 Hyundai Elantra N.

Here’s information about and an interview with four-time CART champion Bourdais, co-driver with Renger van der Zande of the No. 01 Cadillac V-Series.R i

– He co-drove a Daytona Prototype with Alex Popow to victory in the 2012 NASCAR Grand-Am Rolex Sports Car Series race on the 2.534-mile road course.

– He co-drove a Chevrolet Corvette Daytona Prototype to 11th place in 2013.

– He has made 10 INDYCAR starts on the 2.439-mile IMS road course (best finish of fourth in 2014, ’15 and 2018).
- He made his Indianapolis 500 debut in 2005 and has made nine starts overall, with a best finish of seventh in 2014 with KV Racing Technology (Dallara/Chevrolet).

When you think back to that first race back in 2012 at Indianapolis, how special of a win was that for you?

“It was a great day. Victories and firsts like that are always fond memories, especially with the way we had to do it because I think we had to go through the field twice – once in the dry and once on the wets. The weather was quite interesting; lots of precipitation and chaos in the race. It’s always those kinds of race that you reflect on later and it’s the only time that I kissed the bricks, so it was a pretty cool day.”

It’s a different atmosphere from IndyCar to sports cars to IMS. Does it still hold a special kind of magic for sports cars?


“The place is amazing. When you enter the grounds, it’s a very special place and it brings a lot of memories. Every time it’s race day at IMS it has a different vibe. A lot of people are going to show up, I hope. It’s been asked a lot that sports cars come back and I’m fully anticipating a great racing weekend with a big crowd. This place deserves a big crowd because it’s such a big place, and I think Indianapolis being such a motor racing city is always responding well to good shows. We have that in IMSA right now. It’s great to be part of it with Cadillac Racing and it’s a home race with Chip Ganassi Racing, so a lot of things to look forward to.”

Where are the challenges on the track?

“It’s very much a one-groove racetrack and every time you have to get out of that groove – and you will have to – it will make it really difficult. Marbles build up really fast, so for us in the GTPs not being than much faster than the LMP2s and certainly not being any faster in the braking zones, the interaction is going to be quite tricky and will decide the race. How easily your car gets to maneuver around people will be key. Technically, I think it’s a track that is very tricky because you have very pointy apexes and you’re basically braking and shooting for a very specific point. Not like a flowing corner and therefore the margin to hit the apex or not is very small and critical, because if you hit the apex it dictates a very different corner than if you are a half a foot away or not. There is no adjustment from there and they are all pretty long corners, so I think a good front end and getting the car to maneuver around is critical.”

Is virtual energy something you’re aware of during a stint and is there something you can do to try to help with the tools and braking and such?

“It’s something that we’re very much aware of. We can pretty much pick how much fuel we actually put in the car, so it really is virtual energy. I actually came back from came back from Laguna Seca and the strategy was a little bit different there and I was explaining to (wife) Claire that we can to the pit and plugged in but did not change tires and did not actually put fuel in the car. She was like, ‘Say that again. So, you came to the pits. You did not put fuel in the car or take tires, so what were you in the pits for?’ You can be plugged in, not take fuel, and replenish the virtual tank. That is basically dictated when you start the race how much energy the stint with, so it kind of opens up tricks in races when you have a lot of yellows and you’re not actually going to be limited by fuel but limited by energy to get to the end. It kind of opens up different strategies. We’re saving energy the same way. It’s just a matter of a different factor. You obviously keep an eye on the amount of fuel you have in the car. You mostly have to keep an eye on the energy you have left to finish the race. How much regen you get and how you use it is impacting the energy per lap, and that is governing everybody.”

How much more value does IMS add to the sport and where it wants to go?

“With Roger Penske putting so much energy and finance into bringing IMS to its full potential that everybody wants to see in the U.S. and worldwide, I think it makes sense to have a race part of the IMSA schedule. There’s a huge manufacturer push right now. The interest in endurance racing is getting quite incredible to the point where it’s actually going to be difficult to be invited and participate. I’m really happy to see it grow and earn its place back at IMS. All we can hope for is it reaches a peak and attendance is there and everybody brings the energy that a race needs to be successful.”

What has the process of learning the GTP car been like this year?

“It’s a completely new car and we at Cadillac have not really been in a different position than anybody else. We’re figuring things out along the way. It was good to go testing (at IMS); it was really the first test to prepare for Indy since Sebring. So, we learned quite a bit of things about the car, and we went to Road America and it was definitely beneficial. We were on pace and happier right away. The race weekend didn’t necessarily turn out the way we wanted, but it definitely felt like we found a step in terms of pace. It’s a classification that changes a lot. We can see that some cars use the tires better than others depending on the conditions. We’ve been using the harder tire from Michelin ever since Watkins Glen and it’s definitely flipped the order a little bit. The Cadillacs were a bit happier on softer compounds, taking better care of the tires. Now that it’s the harder tire through the summer and it’s going to hold true at Indy, it has been harder for us to extract the most out of it and others have been able to kind of pop up in terms of performance. It’s interesting to see the evolution track to track and circumstances after another. I think it’s all very close. The BoP has worked well. It’s been good racing and we’ve seen a lot of different winners, so I think the crowd has a lot to look forward to. For us, the GTP has been quite different because it’s a heavier car with better tires but more weight with a lot less downforce, so it’s a different combination and you have to be more patient with the car but you still have to push rally hard. The racing has been ferocious, so you have to earn it.”

There has to be a lot of excitement in the Ganassi camp right now?


“Chip Ganassi Racing has had an incredible season, especially on the IndyCar side. They keep showing incredible strength in that program. Obviously, the start of the season for us has been quite challenging. But we’ve shown speed. We’ve just struggled to put weekends together. Road America was a bit of a turning point after a good test at Indy, so we sure hope we can bring some success to the team at home. GM’s headquarters are not very far away from Indy, so it’s time for us to get that Cadillac to the front. And there would be no better place than the Indy road course.”

No. 31 Whelen Engineering Cadillac V-Series.R

Pipo Derani: “It’s the first time here in a long time for IMSA and the first time for the GTP cars, so we’re trying to understand what we need. We have a race coming up soon and we’re in the fight for the championship, so you want to take advantage of a couple of days’ testing. The weather is very hot and likely quite different from what it will be in mid-September, but nevertheless a test that is valuable to us for information so that we can get here with a good and strong car straight out of the truck.”

Alexander Sims: “It’s been a very constructive test. The car has worked well and we’ve learned a lot by being able to have lots of continuous running and do lots of setup adjustments and things with the systems. This is my first time here and I got dialed into the track quite quickly. It’s not one of the more demanding tracks from a sort of braveness point of view, but nevertheless it’s very technical and you have to find a good rhythm. It’s tough to know what the weather conditions will be in seven weeks when we’re back, but the fundamentals of what the track requires from a setup point of view are there, so it’s helpful to be able to run through those in our Cadillac V-Series.R.”

No. 01 Cadillac V-Series.R

Renger van der Zande: “It’s special for us with the Ganassi team and their families living here close to the Speedway. I’m happy that we are testing and trying things on the car that we’ve had on mind but couldn’t try because of limited time on race weekends. From that perspective, it’s already very successful and we seem to have some speed in the car as well. I think in GTP at the moment that it’s clear that the cars are very equal in lap times, so small differences can make for a step forward in qualifying for the race.”

story and photos by Tim Hailey with IMSA, Speedway, and manufacturer reports