Last week, NASCAR tested the muffler that will be used for Sunday’s Clash at the Coliseum.

“Heresy,” some fans cried. They argued that it is against the laws of man and nature to muffle racecars. That noise is an integral part of the fan experience. That you’re not supposed to be able to have conversations during races. Stainless Steel Exhaust Fan

The cars will be plenty loud.

Engines produce power by combusting fuel and air in their cylinders. Each combustion produces high-pressure gases that push the piston up. The same gases make a loud popping sound when they escape the cylinder and finally the exhaust.

At 8,000 rpm, an eight-cylinder engine performs about 520 combustions every second. The faster an engine runs, the more combustions per second and the higher the frequency of the tailpipe noise.

That’s why NASCAR engines sound like grizzly bears and F1 engines, which run at higher speeds, sound more like angry mosquitoes.

Maximum horsepower requires getting the spent gases out of the cylinder as quickly as possible so the next combustion reaction can start. And that’s the problem with mufflers, from a racing perspective.

Mufflers on street cars bounce sound waves from the engine around a metal can. The waves interfere with each other, which decreases the overall volume coming from the exhaust.

Mufflers can also mitigate noise by directing the exhaust through a sound-absorbing material. Borla, the sole-source supplier for this weekend’s muffler, makes commercial racing mufflers that feature a robust sound-absorbing material superior to the commonly used fiberglass.

Both methods slow the exhaust gases — the first more than the second. The ideal racing muffler diminishes sound with minimal horsepower reduction.

Sound-level measurements come in decibels (dB), a unit named after Alexander Graham, not Christopher — and apparently by someone who wasn’t the best speller.

But decibels don’t tell the whole story. Sound intensity decreases with distance, so you need to specify how far away the sound source was.

The easiest way to explain the decibel scale is to relate it to real-world noises, as I’ve done below.

Ringing in your ears the day after a rock concert was a badge of honor in high school. Older me wishes I had been a little smarter.

Hair cells — not to be confused with ear hair — facilitate hearing. Sound bends these hair-shaped cells, and the cells convert sound into electrical signals that the brain interprets. Loud sounds can bend these cells so much that they break.

Unlike animals such as sharks, zebrafish — and even the lowly chicken — humans cannot grow new hair cells. Once your hearing is damaged, you can’t get it back.

A noise mitigation study for the proposed Nashville Fairgrounds track measured a single Next Gen car at COTA generating 112 dB on a straightaway at 100 feet.

A 2008 study measured the sound level inside a Gen-6 car to be an average of 114 dB. The study also compared sound in the stands, the infield and the pits.

Let’s add those numbers to our graph.

The graph data suggests that inside the Next Gen car should be around 10 times louder than inside the Gen-6. Some drivers made new earmolds to cope with the additional noise in the cockpit.

Because of the way sound works, the numbers don’t add like you’d expect them to. A Next Gen car might be 112 dB, but two Next Gen cars are more like 115 dB. A full field would be only 5-7 dB louder.

NASCAR expects a six to 10-dB reduction in sound with mufflers. A 10-dB reduction would make the Next Gen car about as loud as the Gen-6 car was.

Another way of looking at it: Good earplugs reduce sound levels by 25 to 30 dB. Wearing earplugs just barely gets you into the range of being able to hold a conversation if you stand very close to each other and you both shout.

You won’t notice the change in sound inside the track.

You also won’t notice a change in speed this weekend, despite a drop of 30-40 horsepower. The Next Gen car takes around 14 seconds to traverse the L.A. Coliseum’s quarter-mile track. That means cars won’t be going much faster than typical expressway speeds.

If you’re headed out to the track this weekend — despite the mufflers — bring earplugs or over-the-ear headsets. This is especially important for children, as their hearing is more easily damaged.

The NASCAR Cup Series early season swing through the West continues Sunday with a 400-mile race at Las Vegas Motor Speedway.

The first of two annual races at the 1.5-mile track finds Chevrolet driver Ross Chastain atop the point standings, trailed by Joey Logano, Alex Bowman, Kevin Harvick and Daniel Suarez.

Ricky Stenhouse Jr. won the season opener at Daytona, and Kyle Busch scored last Sunday at Auto Club Speedway.

A look at drivers to watch in Las Vegas:

Chastain has started 2023 where he left off at the end of last season, making noise and racing with the lead pack. He has six top-10 finishes in a row, dating back to last season. That’s tied for his longest streak of top-10 finishes.

Logano came within a few feet of winning the Daytona 500 and led 19 laps Sunday at Auto Club. His three Las Vegas wins have all come in the past eight races.

Larson has started the season slowly, but Vegas should be a salve. He has finished in the top 10 in eight of his last 10 starts at the track.

Reddick needs a boost at Las Vegas to bounce back from tough runs at Daytona (39th) and Auto Club (34th). He left both races after accidents.

Blaney has made 48 starts since his last points win. Over that stretch, he has two seconds and 15 top fives.

Wallace has failed to finish both races to date, parking after an accident at Daytona and losing an engine at Auto Club.

NASCAR has suspended tire changer Danny Olszowy and jackman Kellen Mills two races each for a tire coming off Martin Truex Jr.‘s car during last weekend’s Cup race at Auto Club Speedway.

They’ll both miss Cup races at Las Vegas and Phoenix. They’ll be eligible to return March 19 at Atlanta.

Last year, crew members and the crew chief were each suspended four races each for the violation but NASCAR changed the rule in the offseason.

The penalty to crew members was reduced to two races this year. Also, the crew chief is no longer penalized unless they are one of the two crew members responsible for putting on the tire that comes off.

Also this year, if a wheel comes off a car while the vehicle is still on pit road, the vehicle restarts at the tail end of the field. If a wheel comes off a vehicle while it is on pit road under green-flag conditions, it is a pass-thru penalty. Any vehicle that loses a wheel after exiting pit road will be penalized two laps.

Truex served a two-lap penalty during the race since the wheel came off after he exited pit road. He got both his laps back and finished 11th.

NASCAR announced Tuesday that it will make changes to the Cup car for road course events and a majority of races at tracks 1.058 mile and less.

The adjustments — tested at Phoenix Raceway in late January and confirmed Feb. 13 in a wind tunnel test — include a 2-inch spoiler (from the current 4-inch spoiler) and the removal of three diffuser strakes and engine panel strakes. The changes are expected to lead to a 30% reduction in downforce.

Eric Jacuzzi, NASCAR vice president of vehicle performance, said Tuesday on “SiriusXM Speedway” that the diffuser strakes are pieces that hang from the center of the diffuser underneath the car. He said that NASCAR will remove three of the five diffuser strakes. Jacuzzi said the engine panel strakes are metal pieces that sweep outward behind the front tires and make front downforce.

The changes to the car were made after complaints about the difficulty Cup drivers had with passing at many short tracks and road courses last year.

The adjustments will be in place at: Charlotte Roval, Chicago Street Course, Circuit of the Americas, Indianapolis Motor Speedway Road Course, Martinsville, New Hampshire, North Wilkesboro, Phoenix, Richmond, Sonoma and Watkins Glen. Those are all tracks that have the wet weather package (rain tires, wipers, etc.).

The rules will not be in place at Bristol or Dover, which is not included in the wet weather package. Had Bristol and Dover been added, it would have essentially created four different rule packages — intermediate tracks, superspeedways, short tracks/road courses with wet weather equipment and short tracks/road courses without wet weather equipment.

With the rule change debuting at Phoenix, Cup teams will be given a 50-minute practice session on March 10, two days before the Cup race there.

John Probst, NASCAR Senior Vice President and Chief Racing Development Officer said of the rule changes: “We saw incredible racing throughout the 2022 season, especially at the intermediate racetracks. Our goal is to have the best racing possible everywhere we race, so during the offseason, we went to work on adjustments to strengthen the racing on short tracks and road courses.

“Adjustments will be made to the car that will create a significant reduction in downforce, and based on driver feedback and what we saw from the January test in Phoenix, we’re excited to see the results of these efforts.”

The annual Kyle Petty Charity Ride Across America is scheduled April 29 – May 5 in Nevada and Utah.

Petty, a retired Cup Series driver and an NBC Sports NASCAR analyst, will lead more than 125 motorcyclists on a seven-day, 1,500-mile ride, a journey that raises funds for Victory Junction Gang Camp, a camp for children with chronic illnesses. The Petty family built the camp in honor of Kyle’s son, Adam, who was killed in a crash at New Hampshire Motor Speedway in 2000. This is the 27th anniversary ride.

The trip is scheduled to begin and end in Salt Lake City, Utah. Riders will visit Ely, Tonopah and Las Vegas in Nevada and Cedar City, Moab and Salt Lake City in Utah.

Along the way, riders are scheduled to visit the Bonneville Salt Flats, Las Vegas Motor Speedway, Capitol Reef National Park and the Legends Motorcycle Museum.

“Nevada and Utah are two of my favorite states to ride motorcycles in,” Petty said in a statement. “The vast changes in the landscape — from the desert to the red rocks to mountain terrain — paint the most vivid and breathtaking scenes, which I believe are best experienced on a motorcycle. … The Ride allows me to combine my passion for helping others with my love of motorcycles, and it is such a special gift.”

Among those scheduled to participate on the ride are drivers Richard Petty, Ken Schrader, Kenny Wallace and Max Papis, former football star and senatorial candidate Herschel Walker and NBC Sports broadcaster Rick Allen.

Industrial Extractor Fans For more on the Kyle Petty Charity ride, visit the ride’s website.