Trackhouse Simulator

July 25, 2023

Shane van Gisbergen’s incredible victory in the Grant Park 220 Chicago Street Race for PROJECT91 at Trackhouse was a testament to driver skill, team preparation and the value of technology.

Because the 12-turn, 2.140-mile temporary course was a first time NASCAR Cup Series event on the streets of Chicago, the key to victory began on the simulator.

It’s a vital tool utilized by many NASCAR Cup Series teams and at Trackhouse, the first step to victory was developed by Darian Grubb, Director of Performance, at Trackhouse.

The 47-year-old Grubb oversees all the engineering groups at Trackhouse including the No. 1 Chevrolet for driver Ross Chastain, the No. 99 Chevrolet for Daniel Suarez, and the No. 91 PROJECT91 effort that features various drivers from international motorsport.

In addition to serving as the Director of Performance, Grubb is also in charge of race strategy and preparation for the No. 91.

Van Gisbergen became the first driver to win his first-ever NASCAR Cup Series race in 60 years. Johnny Rutherford was the last driver to win in his NASCAR Cup Series debut in 1963 before becoming a three-time winner of the Indianapolis 500.

Van Gisbergen is from Auckland, New Zealand and gained international acclaim with 80 wins and three championships in Supercars in Australia. He understands how to wheel a high-powered race car around road and street circuits, but driving a NASCAR Cup Series car on a street course was a new experience for every driver in the field.

It was the first time in NASCAR’s 75-year history that a NASCAR Cup Series race has been held on the streets.

That is why simulation was so important, not only for Chicago, but for every race on the schedule.

“Chicago was a unique event where we didn’t have all the data that we would normally have to prepare,” said Grubb, who got his engineering degree at Virginia Tech. “Information was coming in piecemeal as they were building the course and doing the layout and we were putting the track profile together as much as we possibly could. There were a lot of unknowns.

“Our typical weeks, we would know all those details down to the last data point of the asphalt, grip, changing of grip with different surfaces. Chicago was a unique event because it was all fresh, but we still went through the same procedures and processes.

“The simulation has become the key to what we do for prep work. We are running the race in the virtual world months ahead of time in most cases to do preparation and lead engineers into directions in how to set up for a course. Once we settle in on where we are heading for a setup, then it becomes more driver training.”

Key elements of the race course, such as brake markers, weren’t added to the track profile until the Thursday of race week as the course was in the final stages of completion before cars hit the track two days later. 

At that point, it became a matter of track familiarization, letting the drivers run laps, get comfortable with the cars, and go through setup changes to see how the car reacts to driver feedback.

Back at Trackhouse racing facility in Concord, North Carolina, the team utilizes its own simulator. As a Chevrolet team, it also uses the General Motors simulator in nearby Huntersville, North Carolina.

At Trackhouse, it’s a “static” simulator that includes track maps, visuals, and TV screens, but operates in a smaller engineering environment and doesn’t feature motion. The seat is static and doesn’t move back and forth in the cockpit, so the driver does not experience the G-loading aspects.

That type of simulator helps with visual cuing and the driver feedback.

At General Motors, the full motion simulator is a full motion rig that slides in all three directions, known as “X, Y and Z” and shakes the car around and runs the track profile of each particular race course.

The driver is strapped into that one and gets the full experience that you would have on the race track.

“That’s the different levels you can run from on your computer desktop doing visuals and using your keyboard to the full static simulator at the shop to the full motion simulator that we have over at GM,” Grubb explained. 

Trackhouse is in a rotation at GM with all the Chevrolet key partner teams and supported teams. They operation in 3-hour blocks for even distribution among the Chevrolet teams.

“What we have here at the shop, we can use any time we want,” Grubb said. “We are running it minimum once a day as a group where we have a simulator driver come in or have some of our engineers go down, fire it up and prove concepts. Because it runs the same exact simulation software, we do to set up our race cars for that, they can go down any time they want, feel the things themselves and see the responses of what it is going to do. We encourage them to do use that as much as possible.

“Then we do general development things. When we have concepts, we want to try, we can do that first without having to worry about putting physical parts on a race car or doing any testing.

“It gives us a good place to do some of the shakedowns of ideas.”

A company in England, rFactor Pro, does the actual scanning of each racing surface. 

“All three OEMs within NASCAR along with NASCAR and Goodyear go together to get these scans done on every surface we go to,” Grubb continued. “We do priority scans for things like this where it was a new event and when other tracks do grinding and repaves like Texas and Darlington, where we try to get a rescan of the patches and things they do. 

“That goes into all forms of motorsports that use that surface, like iRacing and the online groups, anything that would need those visuals and the actual track surface. That is a six- to eight-month process where they are working through it and always tweaking to make things better. Then they will do a release of the data and then we ask for tweaks in certain areas if we believe anything is incorrect.”

The Chicago Street Race created different challenges, however. The city streets are among the most traveled and busiest streets of any city in the world, which can create additional changes to the surface, after the streets have been scanned.

Grubb said Trackhouse confirmed changes to the surface of the streets with Google Maps and Google Street View.

“Then, we put boots on the ground in a lot of cases where we had some sponsor events there a month before and personal friends and people, we called up that would take a bike ride along the course and take photos and videos to show us things we think we might see,” Grubb explained. “Then, we come back and put all those things into play for our simulation.  

“If we saw a big bump in the data, we would go confirm through photos and videos that there is a bridge seam here going from Turn 11 to Turn 12 where the surface changes and you have expansion joints. Those are things that are good to verify how we thought the car would perform because it’s a spot where you would be hard on throttle trying to climb the hill. 

“We looked at those things to make sure it was realistic with the data we were trying to chase.”

City streets also have manhole covers, something that aren’t found on any NASCAR Cup Series oval or permanent road course.

“Manhole covers are in the simulation,” Grubb said. “I don’t think we have the extreme detail to where we have the grip surface of the steel versus the asphalt around it. We use that more for place markers for driver visualization. 

“When we do the track walk, that is when we start making notes on Friday and Saturday morning. Where those big transitions were. How accurate we thought what we did with the prep work was to confirm it and what areas to stay away from and avoid when you are in a high-braking zone and you are going to cross one of those painted lines, or a manhole cover or a seam in the asphalt. 

“That was more driver aspect at that point where they were getting visual clues and trying to make those decisions on what to do in terms of passing maneuvers. You know what you want to do for the primary line, but you also have to plan for when there is somebody on the inside or outside of you, how to approach those areas.”

What made the Grant Park 220 so fascinating is the different track surfaces, combined with the wet and dry tracks, dictated the character of the race. It was fascinating to see how the NASCAR Cup Series drivers quickly adapted to the different conditions of the racing surface in a style of racing that was completely new to most everyone in the field, except for drivers such as van Gisbergen.

“We got to see every scenario that was out there the street course could bring out,” Grubb said. “We had wet spots. We had some puddles. We had some rivers running across some areas. But then we had the concrete, the asphalt, the patched concrete, the new asphalt along with the expansion joints and manhole covers. 

“Every aspect of it is something we had to pay attention. It really is a testament to the drivers and what they have to do to process all the intricacies of the data of what they will have to go around with.”

Trackhouse and PROJECT91 had a secret weapon – Shane van Gisbergen.

“He had so much street experience he was teaching us as we were doing the track walk and showing us a lot of things,” Grubb admitted. “Justin Marks (Trackhouse owner) has that experience as well. It was great to have him walking with us on Saturday morning. They discussed a lot of items about what we thought to anticipate.

“At that point, we weren’t really looking at starting the race in the rain, we were planning on all dry stuff. As it went, we settled in to doing single-file restarts in the wet and then the dry line would form. It pushed you to one direction for the short term and then expanded as the race went on.

“Everyone was learning lap by lap.”

Simulation was the first step in the process that led Trackhouse and PROJECT91 to victory on the Streets of Chicago. But simulators play a key role in preparing for every race at every track on the NASCAR Cup Series schedule.

At Trackhouse, Grubb and his engineering staff work four to six weeks ahead of a race devising a setup of pre-running with engineers that are not directly tied to Chastain’s or Suarez’s team. They work on “best practices” of engineering concept and consult General Motors for recommendations.

That information filters down a month beforehand to zero in on a setup, what questions need answered, whether it be in the wind tunnel or in other areas with technical expertise from GM.

Two weeks out is when the No. 1 and No. 99 teams put those setups in the car.

The week of the race, they will put those setups in the simulator, the driver will be in that seat at the GM simulator testing their setups and prepping for this weekend, fine-tuning the process and make sure everything works all the way up until the cars are loaded onto the truck.

“Sometimes, the cars will be on the way to the race track and we are still in there trying to do some tweaks and final tuning of what we can do for practice and for qualifying,” Grubb said. “It’s a hustle where we are always moving and running around doing different things. We have a lot of people here and it’s nice to direct those efforts to where we think we can create more speed.”


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