Rodney Childers, the crew chief for Kevin Harvick at Stewart-Haas Racing, discusses the team’s blistering start to the 2015 season, how they were able to sustain their desire after last year’s win and much more.
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.
Relax.
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.
Connor Mosack, 23, and Joe Graf Jr., 24, each will drive select races in the No. 19 Xfinity Series car for Joe Gibbs Racing this season.
Mosack, who has a 20-race Xfinity schedule with Sam Hunt Racing this year, will run three races for JGR: Chicago street course (July 1), Pocono (July 22) and Road America (July 29) while also competing in six ARCA Menards Series races for JGR, including Feb. 18 at Daytona.
Graf, who has a 28-race Xfinity schedule with RSS Racing this year, will run five races in the No. 19 Xfinity car for JGR: Auto Club Speedway (Feb. 25), Las Vegas (March 4), Richmond (April 1), New Hampshire (July 15) and Kansas (Sept. 9).
“I made my Xfinity Series debut with JGR last June at Portland and from the moment I made my first lap in their racecar, I realized why they’ve been so successful,” Mosack said in a statement. “Their equipment was second to none and the resources they had in terms of people and their knowledge was incredible.
“Jason Ratcliff was my crew chief at Portland and he’s got a ton of experience. I was able to learn from him before we even went to the track. Just in our time in the simulator, we made some great changes. So, to be back with him for three Xfinity races is going to be really valuable.
“And when it comes to JGR’s ARCA program, it’s the class of the field. After having to race against JGR cars, I’m really looking forward to racing with a JGR car. No matter what track they were on, they were always up front competing for wins. To have that chance in 2023 is pretty special, and I aim to make the most of it.”
Said Graf in a statement about his opportunity with JGR: “Running five races with JGR is a fantastic opportunity for myself and for my marketing partners. I think I can learn a lot from JGR and showcase my skills I’ve been growing in the series in the past three years. 2023 is shaping up to be a great year and I’m pumped to get started with the No. 19 group.”
Ryan Truex has previously been announced as the driver of the No. 19 Xfinity Series car in six races this season for JGR. The remaining drivers for the car will be announced at a later date.
Mosack didn’t start racing until he was 18 years old. He went on to win five Legends car championships before moving to Late Model stock cars in 2019. He graduated from High Point University in 2021 with a degree in business entrepreneurship. Mosack’s first Xfinity Series race with Sam Hunt Racing this season will be March 11 at Phoenix Raceway.
NASCAR’s winter break ends this weekend as Cup Series drivers return to the track for Sunday’s Clash at the Coliseum in Los Angeles.
The second Clash at the LA Memorial Coliseum has been expanded to 27 (from 23) drivers for the 150-lap main event. Qualifying, heat races and two “last chance” races will set the field.
Joey Logano won last year’s Clash, the perfect start to a season that ended with him holding the Cup championship trophy.
Saturday: Mostly sunny. High of 71.
Sunday: Partly cloudy. High of 66.
Garage open
Track activity
Garage open
Track activity
The 2023 NASCAR season will begin with Sunday’s Clash at the Coliseum, the second race on a purpose-built track inside Los Angeles Memorial Coliseum.
Although a non-points race, last year’s Clash generated intense interest as NASCAR moved the event from its long-time home at Daytona International Speedway to Los Angeles. The race was rated a success and opened doors for the possibility of future races in stadium environments.
Year Two will find drivers competing on a familiar landscape but still with a track freshly paved. Last year’s racing surface was removed after the Clash.
Drivers to watch Sunday at Los Angeles:
Logano put bookends on 2022 by winning the first Clash at the Coliseum and the season’s final race at Phoenix to win the Cup championship. He’ll be among the favorites Sunday.
Chastain was the breakout star of 2022, winning a pair of races and generally putting himself front and center across much of the year. Can he start 2023 on a big note? If so, he will have to do so without replicating his Hail Melon move at Martinsville after NASCAR outlawed the move Tuesday.
Sunday will begin the final roundup for Harvick, who has said this season will be his last as a full-time Cup driver. He is likely to come out of the gate with fire in his eyes.
Welcome to Kyle Busch’s Brave New World. After 15 seasons at Joe Gibbs Racing, he begins a new segment of his career with Richard Childress Racing. He led 64 laps at last year’s Clash but couldn’t catch Joey Logano at the end.
Reddick ran surprisingly strong in last year’s Clash, leading 51 laps before parking with drivetrain issues. He starts the new year with a new ride — at 23XI Racing.
After a successful — and controversial — Xfinity season, Gibbs moves up to Cup full-time with his grandfather’s team. Will he be the brash young kid of 2022 or a steadier driver in Season One in Cup?
