NASCAR Cup Series

NASCAR tests mufflers and spoilers at Phoenix Raceway with mixed results

Updated Jan. 26, 2023 3:35 p.m. ET

AVONDALE, Ariz. — The cars sounded better than they felt during NASCAR's two-day test session at Phoenix Raceway.

NASCAR invited six drivers to participate in the test to try to improve the aerodynamic package at short tracks and road courses as well as to test mufflers for events in Los Angeles and Chicago.

The muffler test went reasonably well. There is a concern regarding heat in the car because the pipes extend farther down the length of the side of the car.

That heat issue won't be as much of a concern at the Clash (the Feb. 5 event is on a quarter-mile oval inside the Los Angeles Memorial Coliseum) than the Chicago street course, a full-length race in the heat of the summer.

"The whole muffler package was pretty good," said Brad Keselowski after testing. "It seemed to make the cars actually sound a little better without kind of neutering them.

"I thought it was pretty productive and there's something to work with in the future. ... We have something NASCAR can take to L.A. and feel really good about but probably a good bit more work to be done before this could go to Chicago."

The muffler test showed the cars still to be loud. The Next Gen car, which debuted last year, has the exhaust come out from both sides of the car instead of just the left side, making it a much louder car than drivers (and fans) were used to hearing.

Some drivers said they had to change their earplugs last year because of just how loud the cars are.

"They helped a lot through the garage area, just being around the cars when they started up — they definitely made that a lot more quiet," said Christopher Bell after the muffler test.

"Inside the seat, green-flag conditions, I couldn't tell the difference."

Bell said he was sweating on a 50-degree day.

"It was hot, hot, hot, hot, hot," Bell said. "Back-to-back yesterday with no mufflers and today with mufflers, in the garage area sitting there through changes, it was super hot today. And yesterday it was nothing."

While NASCAR is committed to using mufflers for the Clash and Chicago, many in the industry believe that if fans approve of the sound level and the heat issues are addressed, the mufflers could be added for short tracks, where the noise often keeps fans from even talking to the person sitting beside them during the entire event.

NASCAR had hoped to reduce the decibel level by six to 10 decibels.

"Overall pretty happy with what we had," said NASCAR Vice President of Vehicle Development Eric Jacuzzi. "The sound reduction was in the order of what we expected.

"We got some feedback that we need to keep working on the temperature in the cockpit. We have some paths to go down there."

NASCAR also tested a new underpanel for the car and reduced the rear spoiler from 4 inches to 2.5 inches and then 2 inches.

The idea was that with reduced rear downforce, drivers will have a little more difficulty controlling the car, plus there will be less turbulent air hitting the front of the car that it could make it easier to pass.

NASCAR initially planned to only test a spoiler of 2.5 inches, but drivers asked to see what would happen at 2 inches. The cars were hard to drive, but it didn't appear to give the cars more of an ability to pass.

"It seemed like the smaller spoiler, directionally, helped," defending Cup champion Joey Logano said after testing the 2.5-inch spoiler. "It made us slide around a little bit more on the racetrack. It made us move up a little bit, which made us a little bit more racy.

"I think maybe you can take the whole thing off possibly and be OK."

A 2-inch spoiler is about as low as NASCAR could go at the moment unless it goes with no spoiler. That change, though, could make the cars incredibly unstable and also impact the speeds enough where it impacts brake cooling, which also is a key element for the cars on short tracks and road courses.

"It looks scary when you see there's not one on it," Logano said.

The drivers mostly said that they couldn't tell any difference with the change of the shape in the underpanel. The one being tested is the shape of what NASCAR and Hendrick Motorsports are using for a car that will race in the 24 Hours of Le Mans.

Jacuzzi said the feedback from the drivers was enough that NASCAR plans to not make any changes and won't use the Garage 56 underpanel.

NASCAR had hoped for probably more positive results from the aero test, but that's why it tests — to learn what its theories look like in practical conditions.

As Ross Chastain put it after the first day: "We're going to push for more drag out of the car, so I think the cheapest way to do that is to start taking that stuff off."

And that's pretty much what it did. In cutting the spoiler to 2 inches as well as it being 1 inch narrower than the previous spoiler, NASCAR also changed "stuffers" it uses underneath at the front of the car (extending those to increase front downforce) and then removed engine strakes, and removed some of the pieces of the rear diffuser — all designed to reduce the downforce of the car.

"I was really excited about the short spoiler during single-car runs and then whenever we got in traffic, I was very disappointed in the lack of difference between the short spoiler and the big spoiler," Bell said before the change to the 2-inch spoiler.

And after the change?

"We tried three packages [previously] and I couldn't tell one lick of difference — it all felt the exact same until we did the last package," Bell said.

"I thought that was tremendously better and really hope that we go that direction."

That left Jacuzzi feeling as if NASCAR can make a plan for a path forward.

"We were fairly pleased with that," Jacuzzi said.

The aero experiments also don't have a timeline as far as any implementation for change. Because NASCAR supplies parts and pieces to teams (who purchase them from single-source vendors) and NASCAR would want all teams to get to test any major changes, it was unlikely any change could be implemented until late spring or summer at the earliest.

NASCAR will evaluate the data from the test, take new ideas to the wind tunnel and then possibly have another test before an organization test so all teams get a chance to test the proposed changes.

"No doubt there's some potential on some different things," Keselowski said. "It's hard to quantify right now, but we're in January.

"I suspect there will be some active projects during the season to work on the short-track package to improve the raceability. ... There is some opportunity that shows that it might be worth a deeper dive."

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Thinking Out Loud

NASCAR and the NASCAR Hall of Fame nominating committee has to make a decision on whether Jimmie Johnson is eligible to be voted into the Hall this year for the 2024 class. Now that he is returning to Cup for select races, some would say he isn’t eligible to be voted in since he is no longer retired for a third consecutive year.

My thoughts? My brain tells me he shouldn’t be eligible for the Hall. Just like Jeff Gordon and Matt Kenseth should have had to wait another year after their returns.

But since Gordon and Kenseth didn’t have to wait, then Johnson shouldn't have to wait as well. Granted, Gordon and Kenseth came back in substitute roles and Johnson’s is planned, but it’s the same concept.

The Hall needs as much of a boost as it can get, and inducting people who are still well known to fans and can help promote the museum is a good thing. So there’s good reason to having these drivers eligible as early as possible.

So while the brain says rules are rules and he should wait, precedent and the goals of the Hall (to honor legends in the sport and promote the sport) indicate that Johnson should be among the nominees of the 2024 class.

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They Said It

"I've always felt like I'd come back and have a little fun in a Cup car. I just never saw myself coming back as a team owner." —Jimmie Johnson

Bob Pockrass covers NASCAR for FOX Sports. He has spent decades covering motorsports, including the past 30 Daytona 500s, with stints at ESPN, Sporting News, NASCAR Scene magazine and The (Daytona Beach) News-Journal. Follow him on Twitter @bobpockrass, and sign up for the FOX Sports NASCAR Newsletter with Bob Pockrass.

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