In 1997, Dover Downs Entertainment, then owner of Dover Motor Speedway, announced plans to build a racetrack in Lebanon, TN just 34 miles from the famous Broadway bars. The company’s hope was to secure a Cup Series race date in the Nashville market.
Nashville Superspeedway was opened in 2001 and hosted Indycar, as well as the Xfinity and Craftsman Truck Series races. In the early years, the facility attracted crowds in the high thirty to low forty thousand range, but by 2010 the organizers could barely sell twenty thousand tickets. Nashville Superspeedway hosted what was thought to be its final race in 2011 in front of eighteen thousand fans.
In the nearly decade and a half since, NASCAR and race fans have been trying their damnedest to secure a race date at the historic Nashville Fairgrounds Speedway, which is a short track located inside the city limits. While at times a deal has seemed close, the race is still not on the calendar despite Nashville being an important market to NASCAR.
A solution emerged to get NASCAR back into the Nashville market when the series wanted to take one of Dover Motor Speedway’s race dates away for the 2021 season. Not wanting to lose out on significant TV revenues from hosting a race, Dover offered to reactivate Nashville Superspeedway and shift one of its two dates to this facility. NASCAR agreed and signed the track to a four-year deal. This turned out to be a wise move as the deal was worth roughly $60.1m in revenue to the facility.
The figures in broadcast revenue are the 90% of the race broadcast revenue (NASCAR keeps 10%). 25% of overall broadcast revenue goes into the purse. … So for 2021 Nashville race, track profits of approximately $13.15M in TV revenue after $5.05M of TV money goes into $8.6M purse https://t.co/JyVGW5xOZR
— Bob Pockrass (@bobpockrass) June 3, 2020
Dover Motorsports Inc was purchased by race track conglomerate Speedway Motorsports (SMI) on November 8, 2021 for $131.5m. Assuming similar revenue for both race dates in Dover and Nashville, it would take SMI just over four years to recoup their investment from TV revenue alone. Currently, SMI owns 13 race weekends between their properties: Atlanta Motor Speedway x2, Bristol Motor Speedway x2, Charlotte Motor Speedway x2, Dover Motor Speedway x1, Las Vegas Motor Speedway x2, Nashville Superspeedway x1, North Wilkesboro Speedway x1, Sonoma Raceway x1, Texas Motor Speedway x1. Keep those TV numbers in mind next time you see team owners complaining about charter negotiations.
Nashville Superspeedway is one of three concrete racetracks on the schedule and of the three it is both the largest and the flattest at 1.33 miles in length with corners banked at 14*. Bristol Motor Speedway is 0.5 miles in length with 26* of banking and Dover Motor Speedway is 1.0 miles in length with 24* of banking. For more on the challenges of racing on concrete surfaces versus asphalt, be sure to check out my piece on Dover Motor Speedway.
How To Survive The Heat
One of the biggest challenges for drivers and crews alike will be the heat. Temperatures in the Tennessee summer are no joke and this upcoming weekend will be no exception.
We’ve discussed before in my piece about Martinsville Speedway how teams keep their racecars cool, but keeping the driver cool is just as important. Below, you can see the in-car thermometer in Noah Gragson’s car reads 138.2*F (59*C) as he rides around under caution during the 2022 Xfinity series race in Nashville.
The highest number I can ever recall seeing was 158*F (70*C) inside Justin Allgaier’s car during the 2018 Xfinity Series race at Chicagoland Speedway.
For context, the hottest recorded air temperature on planet Earth was 134.1*F (56.7*C) in Death Valley, CA. When using a sauna set to 150*F (65*C) the recommendation is to limit your session to between 15 and 20 minutes. The 2018 Chicagoland race lasted 2:13:34.
Last time I checked, people don’t normally have much clothing on when they’re enjoying a sauna session. So, what does a NASCAR driver wear during the race? Their base layer consists of four items. First, is a set of two-piece fire retardant underwear that “must cover from neck to wrists and ankles.” The other two items are a set of fire-retardant socks and a fire-retardant head sock and/or helmet skirt. The base layer essentially seals in the driver’s body except for a small opening in the head sock over their face. These undergarment items must be compliant with SFI 3.3 safety standards. Over top of this, the driver will wear a one-piece, two-layer fire suit compliant with SFI 3.4/5 standards as well as their driving gloves and shoes. Essentially, the driver will be encased in a three-layer fire-retardant cocoon and forced to sit in a sauna for hours at a time.
If you’ve ever seen a photo of a driver in a fire suit and wondered what that umbilical cord-like thing hanging out of the side was, today is your lucky day.
That was fun! Let’s do it again tomorrow. Thanks for the ride @KauligRacing pic.twitter.com/u7DUsMhnj5
— Kyle Larson (@KyleLarsonRacin) May 14, 2023
That cord in question is part of the cool suit system and is one of the most important advancements in driver cooling. The cool suit is a fancy shirt that acts like a radiator for the driver’s body. It consists of two pieces and is worn underneath the driver’s fire suit. The first piece is an external heat exchanger that is usually fitted behind the driver’s seat and the second is the shirt itself.
The black hose hanging out of the fire suit is what connects the two parts. When the system is running, it pumps cooled fluid through the hose that snakes along the shirt to try and keep the driver’s core body temperature from getting too high. Hyperthermia, the beginning stages of heat-stroke, begins to set in at a body temperature of around 102*F. During hot races a driver’s body temperature can approach 101*F.
Drivers also have a helmet blower that attaches to the top of their helmet. There is an air intake at the left side B post column right behind the window net. Air flows into this system where it is both cooled and filtered. The helmet blower only cools air down about 12-15*F below ambient temperature, so on a hot day it’s not quite air conditioning but the fresh air being forced into the helmet is certainly a massive help.
One of the hottest parts of the racecar is the floorboards. The left-side exhaust runs almost directly under the driver compartment. Teams install heat shields onto the exhaust but significant amounts of heat will still be conducted upwards into the floor of the racecar. To combat this, most drivers will wear detachable heat shields on the heels of their racing shoes.
Even with these heat shields on the bottom of their shoes, temperatures can at times become unbearable. Immediately after the 2022 Xfinity Series race in Nashville, AJ Allmendinger can be seen icing his feet with track medical staff and team personnel.
On a 2010 episode of ESPN’s Sports Science, TV crews and scientists followed Denny Hamlin during the Coke 600 race weekend at Charlotte Motor Speedway. They noted that with temperatures inside the car hovering around 130* F, Denny’s body produced roughly 3.5 pints (1.6 liters) of sweat per hour. Over the course of the race, he lost almost 13lbs (5.9kg) of water weight. Keeping a driver’s hydration levels up during a race is crucial.
During a pit stop, you will see an extra crew member approach the driver’s side window. This extra over-the-wall member isn’t assisting with the pit stop, they are fulfilling the driver service role. On a normal pit stop they will jump over the wall with the pit crew, exchange the driver’s empty drink bottle for a full one, and remove a windshield tear-off. The driver service person only has a couple of seconds to complete this exchange before the pit crew has finished changing the right-side tires and they must be out of the way so that the left side can be serviced.
During hotter races, this exchange can become slightly more complicated. Drivers will often ask for either an ice pack to put inside their fire suit or a cold bottle of water to pour on themselves. This added step of handing over the ice pack or bottle to the driver may not seem like much but it can cause hang-ups for the driver service person. The opening between the car’s A-post and the window net is fairly tight and the crew member must reach further into the car to ensure that the driver can reach what they are being handed. Even if the exchange only takes one second, that’s roughly 20-25% of the time that this crew member has to work with in the first place. You can see the driver service crew member approach the left side of the cars in the video below.
Most teams place both the drink bottle holder and the radio pouch on the left side door padding of the race car, where it is easily accessible. If the driver comfort service member is trying to rush their movements, it is very easy to knock against the radio switches with one of the drink bottles. I’ve done this a few times where I accidentally switched the radio either to channel 2 or off.
Heat can play havoc for the rest of the crew members as well. Teams will have to push their cars and equipment from the garage out to pit road, set up the pit boxes and then bundle up in their fire suits to face the day. Even once the race is over, the pit boxes must be torn down, equipment pushed back to the haulers and cars must be pushed through technical inspection and tear down.
Excessive heat can also cause numerous IT issues as monitors, computers and other electronics overheat during the day. Some pit boxes are fitted with custom shades to at least keep devices out of direct sunlight, but sometimes even that isn’t enough. There have been multiple instances during hot races where I have had to stick a laptop or tablet on top of the ice in our drink cooler for a moment in order to regain functionality.
As if that wasn’t enough of a challenge, increased temperatures decrease grip levels. If I had to guess what the word of the weekend will be, my guess would be “sketchy.” For more information on how track temperature affects grip level, you can check out my piece on Charlotte Motor Speedway.
Aero racing plays a much bigger role on hotter days than it does on colder days. Heat reduces mechanical grip between the tires and the racing surface, leaving the driver more reliant on aerodynamics to get through the corner. A lot of the accidents this weekend are not likely to be initiated by contact between two racecars but instead by a disturbance in the air around a car causing that driver to lose control.
The lack of grip offered by the racing surface in mid-summer’s heat is readily apparent in qualifying sessions. Last year the majority of the Xfinity series field had some sort of issue on their qualifying lap with multiple drivers losing control and crashing.
Just remember all of this when you’re sitting in your air-conditioned house, drinking an icy cold Big Machine Vodka Spiked Light Cooler* that the drivers and crew are having a slightly warmer time.
[Ed note: *Thank you Parker and Big Machine Vodka for letting us use all these photos for free. – MH]
The remarkable thing is that more weight-sensitive series don’t run any cooling systems – notably F1. Those guys have hotter cockpits, no suit or helmet cooling, they’re open to the sun, and endure *six times* the g-loading. I remember a race in Malaysia in the 2000s where it was 100f with 90% humidity, and Michael Schumacher popped out of his car at the end of the race, took off his helmet and balaclava, and -his hair was dry-. An absolute machine. Alonso (then a youngster) was on the podium with him and looked half dead.
So you’re telling us that Jason could have fooled us all and explained this as the cool origin of his arm tube — a built-in cooling system stitched under his skin. But then he had to get all gross and graphic and honest about having to juice himself every hour.
I read Mario Andretti’s book about racing and one of his biggest complaints about the warm weather racing. He said as he’d circle past the infield crowd area, he could smell the various meats fans were cooking on their grills. He said he’d start salivating and sometimes lose his concentration. Different times the 60’s racing scene.
A nice addendum to this piece might be the different types of cool shirt systems. You have the ice water cooler type that’s been around a long while, but now you have the Chillout A/C units, as well. They’re lighter, as they don’t require the massive volume of water and no need for ice, but they’re much more expensive and take a large power draw. They also expel a lot of heat, so getting air through that unit and out of the cabin is critical for closed-cockpit cars.
Excellent post as always, I love seeing these come up. Aedan’s series is a great example of what my membership here is supporting- keep up the great work!
Easy – replace them with robots. How hard is it to drive a mobile billboard around in circles for drunk rednecks to watch? Just let the highest paying sponsors draw straws to decide which one wins. Drivers can still give interviews and pretend they were in the car. Nobody would notice the difference, just like pro wrestling. It may already work like this.
What a miserable human being
Probably a troll post but if it isn’t, then one of the dumbest things I think I’ve read a very long time.
I’m sure it isn’t true. But why the animus? In mock dog-fights f-16’s under A.I. control do very well. Why not an AI driver?
Mighty fascinating!! While I don’t follow NASCAR these articles are always interesting for those who want a bit of a deep dive in such subjects. There’s so much more to car racing than just driving fast.
Many years ago I saw an interview with some retired NASCAR racers (I think one of them was Junior Johnson?) who were reminiscing about how they would prepare themselves for the conditions of summertime racing by going for long drives at night during their days off in street cars with the heat turned on full blast with the windows rolled up in the spring and summer. This was in the Deep South… and this was in the days when they’d be driving tri-five Chevys when they were still late-model, that’s how long ago this was. Times sure have changed, to say the least.
Fascinating article, thank you.
You may be interested to know that WEC (Le Mans) car must have air conditioning, but these are true “closed cockpit” cars.
https://www.24h-lemans.com/en/news/heat-another-thing-for-drivers-to-deal-with-46897
Having driven a few factory-built racecars with A/C, I’ll note that the A/C in these cars is just good enough to keep the cabin heat below the required max. It’s not a refreshing breeze like your road car. Driver cool suit systems are still often used.
For Lemons racing in Nor Cal we used cool suits all the time. I bought a real cool suit shirt (though i know some people bought a very tight t-shirt and then spent a couple hours sewing tubing onto it. The quick-connect connectors you can get on McMaster Carr and they’re not super cheap but I remember them being less than $10 ea. need to get matching ones for all your buddies shirts. The cooler was, well, a cooler, and we could fit in a block of ice vertically. Had ~4” of water in the bottom and had a cheesy bilge pump from your local boating shop in the bottom of it. Worked great. One vertical block of ice would last about 45min in 110F. Vertical so it would last longer. If you need more, do two vertical blocks…. It was honestly glorious to get in the car with that thing… sweltering in the pits, when you’d get in the car you’d turn on the pump and get what was essentially a spash of cold water on your body. Glorious!! Had to cycle the pump it was too cold.
If you do it, remember, you want what some would call a “euro-tight” t-shirt.. better conduction! I think aside from the shirt the whole thing was around $50… well spent.
One race in SoCal was so hot that after the race on the drive back to NorCal (my truck didn’t have AC) I rewired the pump to fit a 12V plug, seatbelted it next to me, dumped in the left over ice and used it until the sun went down and hte ice was gone…
No wonder 5he Phoenix raceway nascar races are in winter. But maybe racing in Phoenix would be better than Tennessee right now. Both places are hitting the same temps, but Tennessee has brutal humidity. I can handle 110 in AZ. I almost passed out from heatstroke in 90 in GA. Whole different beast the heat is in the South.
No Joke – Pennsylvania boy here, we get the humidity but not the extreme heat typically. I spend a lot of time in the deep south sometimes for work – 105 in Alabama, 110 in Arkansas and Texas. All with stifling humidity. I went backpacking in New Mexico in high school in 100 weather and it was a cake walk in comparison.
Hey PA boy here too!
This article was truly fascinating. Thank you!
Good article, and something that doesn’t get enough attention. On a somewhat related note, I’ll be at a 4 day music festival next week with temps in the high 90s – 100 range. I’m thinking a cool shirt, a battery operated pump, and a cooler on wheels….
I remember many years ago watching drivers crush Styrofoam cups into their shoes trying to create a heat shield. I can’t stand idiots who say that drivers aren’t athletes.
As much as a golfer is anyway.
Useless info time: the US Army uses cool shirts as part of the Air Warrior system. You can pick up surplus vests on eBay. The later model vests look like they have the same connector as the umbilical photos above but I couldn’t find a connection between the manufacturer Allen Vanguard and Nascar.
The first time you use a cool shirt on a hot day is like the first time you have sex. They’re almost that good.
I looked into the connectors used by the cool shirts you buy at places like summit, and found out they’re shared with medical devices, so unfortunately not a cheat code to getting them cheaper. Cheapest per connector I’ve found is to buy their shirt drain / rinse kit which gives you 2 females + 1 male for I think 40. Otherwise they want 25 / connector. (you need 2 per shirt)
Reason for doing this is in really hot races, if you’re not one of those fancy teams with an air conditioned RV it’s very pleasant to also have a cool shirt setup for sitting around in the paddock. Our drinks cooler has a few plugs in the back of it powered by cheap $5 pumps from amazon that run off a usb plug.
One other thing I’ve considered doing and am curious if others have is to turn our cool shirt system into also our hydration system. You’d probably want interchangable bite valves, backflow valves, a shirt tube sterilization regime, etc., but if you’re already going to be dumping 10lb of ice in there every 1-2 hours, may as well get to enjoy drinking it as it melts if you’re the driver and less to spill out the side then drain from the car.
You can buy those medical device cooler kits pretty cheaply, used, on eBay. People have them prescribed by their doctor after shoulder or knee surgery, then after the healing is done the rig sits around in the basement until they inevitably get listed on eBay. You can usually find the whole rig – cooler, pump, power cord, and the therapeutic pad – for under $75. The pumps are usually 12 volt, so you can cut the cord from the transformer and wire it up to your power source. The first cooling shirt system that I used in LeMons was based on this type.
Are they “tactical”?
Wait: that’s a legit use of ‘tacti-cool’!
😉
Seems awfully complicated.
When I was a kid we just opened the vent windows and the floor vents, and put Slushies in between our legs
I remember a few years back, I think the first year after his Cup series rookie season, Bubba Wallace being interviewed after a close race on a not-uncommonly hot day. He started okay, but then started visibly swaying, became increasingly incoherent, and while he gamely tried to keep going, he haltingly had to end it; it was pretty clear he was barely conscious at that point.
They panned back to him a few minutes later to show us he was okay, and he was sitting on the track up against a barrier, with icepacks draped all over him and his head in his hands. That visual really drove home for me how grueling just being in a race is, nevermind performing the actual activity of racing.
Atlanta, 2020. I’m still mad he wasn’t immediately hospitalized. I’ve seen things get very bad for people who were at just that point.
Thank you! I couldn’t recall which race, only that I thought wow he looked bad and he was a young guy in top flight shape, not like the rest of us.
This was Rachel Daly from the National Women’s Soccer League going down at the end of an afternoon match in Houston. The training staff did a near perfect job of racing onto the field and getting cold wet towels on her throat and wrists within a matter of seconds. She was still hospitalized for the night. NASCAR drivers are absolutely athletes, but I’d professional soccer players are in even better cardio-vascular shape, and this was a near-run thing. I think Bubba was just about here, and if a heat casualty isn’t immediately treated they become more susceptible to similar problems in the future. Can be career-threatening for an athlete. They don’t play afternoon games in Houston anymore.
https://www.youtube.com/watch?v=t08RROQ6pPI
What method is used to cool the fluid in the driver’s cool shirt system? In the grassroots endurance racing world, we use a modified drink/food type cooler filled with ice and water, plus a 12 volt pump to circulate the fluid. I would suppose that ice isn’t feasible in the NASCAR series, because replenishing ice during pit stops takes too much time and makes a mess.
One thing I remember from Paris-Dakar teams (and something mentioned in a recent Aging Wheels video for a battery pack) was a Peltier module, mostly commonly being attached to the back of the driver’s seats. If properly ducted the Peltier module would pull the heat from the driver’s back (where heat would concentrate) and throw it out the window. My guess is something similar is used in stock cars.
Peltier coolers are notoriously inefficient and dont scale well so I dunno how effective one would be for moving that much heat vs. a proper heat pump. They’re best for keeping a CPU or beverage cool rather than a driver:
https://www.thermal-engineering.org/peltier-cooler-small-scale-thermoelectric-varieties/
If anything I think a *normal* A/C system should be part of the specs for these cars as pushing cars to their limits while keeping their drivers safely away from THEIR physical limits is the whole purpose of racing and A/C is very much part of that in any modern car.
By the time you have 3 layers of nomex on, you’ll start to overheat if you’re over-exerting yourself even in 40* weather. The heat in the cabin only adds to the heat you build up from exercising while inside an insulated suit that should allow you 9 seconds of standing in a fire without 3rd degree burns. Having something like a cool shirt and ventilation going inside the suit is far more useful than cooling the cabin itself.
Which is crazy, because, according to every commercial I’ve ever seen, and we all know commercials are real life, those guys do absolutely everything while wearing those firesuits- mowing the lawn, getting pizza, going to cookouts, etc
Oh I’m only talking about the mechanism of cooling.
Compressors and freon are more efficient than Peltiers. That’s why cars use them in the first place even though Peltier are intrinsically more reliable and simpler. Absolutely keep the cool shirt and suit ventilation. That’s not (conceptually) so different from cooled seats anyway.
A cool shirt attached to an A/C system instead of a Peltier I think will be more efficient (thus reducing the load on the engine) and be able to dump a lot more heat. Plus as I said A/C is part of pretty much every modern car so it should be punish tested by racing as much as anything else on a modern car.
If your point is that shirt and suit needs portable cooling then use a Peltier for getting around (or just an ice bucket) and hook into A/C once in the car.
I missed which driver it was on the Xfinity race in Nashville tonight, but he got quite “heated” with his crew chief and radioed him not even to put the car on the trailer next time unless they’d worked out suit cooling and air conditioning. 138 on the side of his seat. I come from a career that takes heat VERY seriously, I don’t blame him in the slightest. If you’re a heat casualty, once your body’s ability to thermoregulate gets altered you tend to get in trouble even more easily the next time.