New Downforce Package Makes Phoenix Debut

March 10, 2023

Beginning with Sunday’s first short oval race of the season at Phoenix Raceway, the NASCAR Cup Series drivers will have their hands full with a new low downforce package.

That’s just what many of the racers in the series want because it brings car control back into the drivers’ hands.

Less rear spoiler, along with less downforce to the underwing of the NASCAR Cup Series cars will create the least amount of downforce on the cars since the 1990s.

“We took a lot of downforce off the cars, but we also took a lot of drag,” explained Trackhouse crew chief Travis Mack, who oversees car preparation and race strategy for driver Daniel Suarez in the No. 99 Freeway Insurance Chevrolet. “When you take drag off the car, it almost makes the driver feel like they have a lot more horsepower.”

Combine that with less grip, however, and that will have the cars sliding around more on the short ovals – tracks one-mile or less on the NASCAR Cup Series schedule.

Mack believes Sunday’s United Rentals Work United 500 at Phoenix Raceway won’t look much different than last year, but it will have some differences for the drivers behind the wheel of the stock cars.

“It will be curious to see what happens in this race and how it compares to last year’s races, but all-in-all I don’t think it changes too much,” Mack said. “When we get to Loudon and Martinsville and some of these other short tracks, it will play a bigger role.

“It’s impressive what we are doing with the tires and the downforce package. Look for tire falloff and how these cars are handling is the biggest issue.”

Travis Mack

The most important difference between the new package and the previous high-downforce package is give the driver more control over the performance of the car.

The harder a car is to drive, the more influence the driver behind the wheel has on how it performs on

the race track.

Compared to a high-downforce car that is firmly planted on the track with high grip, the lower downforce package produces less grip, creating more interesting racing.

“The cars are going to be slipping and sliding,” Mack predicted. “You will see drivers making more mistakes. We are even nervous about qualifying now. The drivers are so used to going out to qualify and the cars are glued to the race track.

“Now, qualifying, they will go out there slipping and sliding all over the place and it’s really going to be in the driver’s hands.

“I think you will see guys that hold on longer, take care of their tires, do better on the long runs and short runs. Every lap isn’t going to be a qualifying lap. Guys will have to manage their cars over the long run, and you will see cars coming and going in the field more often.”

To create the lower downforce package, the rear spoiler angle does not change because the spoiler is just two inches. That size spoiler creates much less aerodynamic drag and downforce.

The real difference comes from the modified underwing of the car.

“NASCAR did a good job and kept the balance of the car fairly similar to what we had before, but they knocked off quite a bit of downforce from underneath the car as well,” Mack explained. “The underwing is very, very sensitive. The smallest changes to the car can make a huge impact. That’s what we did with our data during the offseason.

“Last year, with the underwing, we had one-hundred-and-fifty-thousandths tolerance that we could play in to pass tech. This year, we are down to a one-hundred-thousandths. They knocked off fifty-thousandths of underwing tolerance we could have. That alone took off some of the downforce we had last year.

“They also removed some of the diffuser skirts. On the back on the car, we had those little fingers hanging down and that really smooths out the air coming off the back of the car and creates a lot of downforce. They removed three out of the five that are there and that significantly took away a lot of the downforce on the cars.”

With so little downforce, NASCAR gave the Cup Series teams extra time in practice to fine-tune the race cars to determine which shocks and spring combination will create the proper setup to the driver’s and team’s needs.

“That’s why NASCAR gave us a 50-minute practice session this week,” Mack continued. “We have 50 minutes and one set of tires to answer all of those questions ourselves. We’ll make our best guess at it.

“I have a really smart group of engineers and everybody at Chevrolet, we have worked hard during the offseason, and we will show up with a better package.

“The springs and shocks change, but not too much from what we had last year. But you will be looking at long-run speed versus short run speed. We are tuning those types of things every single week. Even with the high-downforce package, we are trying to understand everything with this car. That is something we tune. You see it throughout the entire garage. Guys with stiff springs and soft springs.

“There are 100 different ways to get to the same point. We will just keep working on those packages and try to find the right one for our driver.”

When a stock car has less downforce, it is slower in the corners. To make up for that, the car needs an engine with more torque coming out of the corners so a driver can stand on the accelerator to get more speed and grip down the straights.

“ECR does a great job with their engine package,” Mack said of the team’s engine supplier. “They look for horsepower, but we also have to have the torque to get off the corner as well. I know ECR will give us the best engine they have.

“We’ll take all we can get – all the downforce we can get and all the motor we can get. That all makes the car goes faster.”

That makes it even more important to match the Goodyear tires to the new setup on the race car.

“Tires are pretty important in Phoenix already,” Mack continued. “In the NASCAR Xfinity Series and Truck Series, you could see guys take tires in 20th and drive up to the lead.

“Last year, with the Cup car and high downforce package, you didn’t see that as much. I expect that to come back this year. Tires will be really important for guys in the field. You will see a lot of different strategies similar to what we had at Las Vegas with drivers staying out, taking four tires, or taking two tires to try to make up that track position.”

Because mid-corner speed will be reduced, that will create different racing lanes for the 36 drivers that take the green flag in Sunday’s fourth NASCAR Cup Series race of the 2023 season.

“You are really slowing down the middle of the corner speed with the low downforce, but at the end of the straightaways, we are running the same speed or maybe a little bit faster,” Mack explained. “They will have to use the brakes a lot harder, slow down in the corner with the lack of downforce. When they get back on the throttle, they will be slower with less drag. It will feel like they have a lot more motor, they will be spinning the tires.

“It’s going to be a lot about throttle control.

“I can see guys, especially out of Turns 1 and 2 all the way to the apron and all the way up to the wall.”

Mack believes it will favor drivers who are good on long runs, including his driver, Daniel Suarez.

Mack praised Suarez for his ability to manage his tires, not abuse them on the first few laps and come on strong over the last 30 or 40 laps during a fuel run.

Mack believes both drivers at Trackhouse – Suarez in the No. 99 and Ross Chastain in the No. 1 Chevrolet – are great short oval racers that can easily adapt to the new package.

“Ross was really good last year with the short track package we had last year with the high downforce,” Mack said. “He got to test out in Phoenix, and he was really good with every package we threw at him.

“I don’t think it will affect him too much when he is slipping and sliding a bit. I think you will see guys get into each other, tempers flaring because the car isn’t driving as well.

“We’ve looked at the short tracks over the offseason a lot on the 99 because if we can improve on the short tracks, we’ll have the total package.”

Travis Mack

The challenge of a new package is what drives the crew chiefs, engineers, and crew members up and down pit lane in the NASCAR Cup Series. That’s where they are able to formulate and process solutions to a new challenge on the car.

“We are constantly tweaking and tuning,” Mack said. “If you miss it by a little bit, you won’t be running in the top 10.

“It’s really important to unload off the truck and be consistent and good off the truck so the driver can start making laps right away. You can fine-tune the car if you unload fast off the truck. It’s a little more difficult if you are one-second off the pace. It’s more difficult to find that speed in a practice session. You have to wait until the next week, abort that setup and review everything with the engineers and the driver.

“I feel confident in my guys this year. We are showing up really close to the competition or the top five and top 10.

“We are looking to capitalize on our first three runs this year, top 10s. We believe we’ve had faster cars than what we have finished, but we are going to put it all together one weekend and shoot for that win.

“It all comes down to the little details, the pit stops, the track position, the qualifying effort. It’s exciting, that’s for sure.”

When it comes to racing at Phoenix, Mack believes Trackhouse has two of the best at that unique track. Chastain finished second to NASCAR Cup Series champion Joey Logano in last year’s NASCAR Championship Race by 235 feet.

Suarez has also proven to be very good on the shorter ovals on the NASCAR Cup Series schedule.

It’s an important weekend for Trackhouse, as well as the other teams in the NASCAR Cup Series.

“This weekend at Phoenix and first short track this year sets us up for the rest of the season and gives us a decent package that we can start from and work on for the rest of the year,” Mack said. “I’m looking forward to this weekend. It’s really an important weekend to show that we can have speed at short tracks this year and compete. We are going to come back to Phoenix in the Fall. That is our Championship Race. Our plan is to be in the Championship Four and going for that trophy.

“This is a really important race for us to get a good notebook for that Championship Race in November.”


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