Aero Wars: The uphill battle NASCAR has gotten itself into
July 25th, 2015 by JaimeB
The year is 1968. The racing series: Formula 1. Colin Chapman bolts a small front wing and a rear spoiler onto Graham Hill’s Lotus 49. The result is tremendous. All Formula 1 teams follow suit in affixing their cars with some kind of aerofoil-shaped device on their cars. Dubbed “guillotine” wings because….well never mind, let’s just end that with the fact that they were banned at one point in 1969 and returned after the FIA was able to drum up some rules on how they could be attached to the cars.
Bruce McLaren in 1968, featuring an early-spec wing on the back of his Formula 1 machine. (Photo Cred: McLaren)
What does the 1968 Formula 1 season have anything to do with NASCAR? That’s like asking what did the Wright Flyer do for Boeing’s 747! The moment Chapman bolted a wing onto Hill’s car, it started a revolution. Many of us on iRacing have the Lotus 49, arguably the last successful car without aerodynamics on the minds of the designers (if you don’t count the 49B…which had wings…but I digress…), and those who have driven the virtual version know how slow it is in the corners, how hard it is to stop, and how quickly you wind up somewhere else when pressing the throttle due to its low drag. Manufacturers and designers learned quickly that speeds increase with downforce, braking distances decrease, and laptimes will tumble as downforce is added. This led to new tires, new suspension systems, and a revolution in how the cars actually looked. In fact, the Lotus 79 was designed in 1977, just 9 years after those wings were bolted to the 49. Compare the two, and they look like they’re separated by much more than that.
Fast forward 30 or so years, long after the rest of the world has adapted wings, diffusers, and even dive planes to cars, and we start to see a revolution in NASCAR. From its inception in the late 1940s to the mid-to-late 90s, cars weren’t built with aerodynamics in mind. Completely mechanical in their operations, it was big front springs, tiny sway bars, and heaps of body roll. Rumors have been going for years that Jeff Gordon’s T-Rex car was the first “downforce” car to hit the track way back in 1997, but it was subsequently banned as we all know. The car is actually sitting in the Hendrick Museum today, and it has a very different “look” to other cars of its time for sure. Was it built for aerodynamics? Probably, but we do know that downforce cars came back no later than 2005 and were not banned after stomping the field on at least two occasions: Michael Waltrip at Charlotte, driving the “untouchable” #15 Chevy until he crashed on a late restart, and Kyle Busch’s first Cup Series win at Auto Club Speedway. Just one year later, everyone knew about the “twisted” cars, and “aero push” became a well-known phenomenon.
Believed to be the first “successful” coil-bind car in then-Nextel Cup, Michael Waltrip’s 2005 car left the field behind whenever he took the lead in the fall race at Charlotte. He wouldn’t finish though, he got caught up in a crash late in the race. (Cred: Motorsport.com)
So now it’s 2015, and we’re in the throes of another battle between rule makers and the engineers. Drivers say they can’t pass, fans say the racing is boring, and NASCAR seems to be in love with getting in front of cameras and saying “We’re going to cut downforce and make the racing better.” But will it make it better? We’ve gone down this road before, and we can say it will. The series that started the aero-craze back in the 1960s went on a similar “Let’s cut downforce” rampage that NASCAR is now going on, but it ultimately failed. The 2008 Formula 1 championship was decided by a pass made in the last corner of the last lap of the last race of the season after the “champion” had already finished the race and was celebrating. Sounds crazy, but it’s true. The FIA stepped in and said that, in 2009, all the extra fins, wings, barge boards, vanes, and strakes would be gone from the cars. The rear wing would be narrower and taller, the front would be wider and lower. This was all in an attempt to aid passing, and to make the racing more exciting. Once that statement was issued, the FIA began its game of “catch-up” with the engineers. Brawn GP, Williams, and Toyota F1 all found loopholes to get tons of rear downforce back through a “double-deck” diffuser. The next year, McLaren created the “F-duct”, a device used to stall the rear wing on straights while still making tons of downforce in the corners. Blown diffusers eventually caused the FIA to say “You get one exhaust pipe, and it’s coming out of the top of the car.” Engineers were finding ways to get the downforce back, regardless of what the FIA did. Every change was a response to an engineering advancement, and earlier this year the FIA accepted rule changes over the next two years to increase downforce, add power, and do more to give the cars more grip. Why? Because the downforce reduction failed miserably.
The first COT race in 2007 resulted in purely-mechanical setups, yielding whatever this body attitude is called. (Cred: Motorsport.com)
Sadly, I can see NASCAR going down the exact same road as the FIA and its engineers went down. When they made the new COT in 2006, the idea was “less downforce”, and it sort of worked. We saw cars flop over so far in the corners that we thought they’d just fall onto their doors. It wasn’t long before teams started stuffing big springs in the front and rear and turning front shock rebound to 11 and getting the downforce back into the new car. I spoke to a mechanic from Hendrick Motorsports about this a few months ago, and he said, “We were getting the same downforce out of the 2012 COT that we were getting in the mid-2000s.” Impressive, for a brick. If the #48 from 2007 was sat next to its younger sibling from 2012, the difference is amazing. The 2007 car would be straight, square, and boxy. The 2012 car? Twisted, shifted, and more aggressive in terms of aerodynamics. NASCAR probably saw where that was headed and introduced the Gen-6 cars, with the entire body mandated, save for the small panel at the top of the door. They had more downforce, “looked cool”, and had no problem setting records at any track. But again, fans complained that the racing was bad, so NASCAR tried to cut the downforce again, and coupled it with a power reduction. That didn’t work either, so they decided to test a “low-downforce” configuration at Kentucky a few weeks ago. Did that work? Well, we honestly don’t know yet.
Comparisons between the 2014 and 2015 races at Kentucky showed higher rake angles and lower splitters, an indication that teams were trying to get downforce back into the cars. This requires stiffer setups, which will eventually turn into a more drastic aero-push after teams develop the cars. (Cred: 2015 image from Lowe’s Racing, 2014 from Motorsport.com)
While the announcers, drivers, and fans are all fawning over the new rules package, few are considering what actually went into that race. If we think back, the last two times downforce was cut from the cars has failed. It was done in 2007 when the COT was introduced, and in 2015 when the Gen-6 was downgraded. Yes, the first COT race was crazy, even by Bristol’s standards, but that quickly went away as soon as teams were able to claw back into the aerodynamic world they had with the Gen-4 car. The same for 2015, when teams had ample time to adapt the cars over the winter months to get back the downforce they lost. As for Kentucky? That package will only be used for 2 races, and neither of which are in the Chase. If I’m the engineer on one of the teams, I’d simply say, “Why bother?” There’s no reason for teams who were in the chase to work on that rules package at all since it isn’t permanent. So, as a result, we saw the same thing we saw in 2007 at Bristol, when the undeveloped “new car” hit the track. That’s not to say they didn’t work on the Kentucky cars at all. Like the caption in the above photo says, the #48 team obviously built a car that was intended to produce more downforce, and likely had a much stiffer spring package than the 2014 car. Without large amounts of time devoted to developing it, it was just a fun outing for those guys. Kyle Busch is on a mission, and when he’s on a mission, he’s going to win the race somehow, and they likely put a lot of time into that specific race. Anyone else find it interesting that he won New Hampshire as well? Go ahead and attribute that to “his mission”.
The science behind a pass is simple: If a trailing car goes faster than a leading car, the leading car will get overtaken at some point. The problem lies in why the trailing car is faster. In most cases these days, it’s faster because it’s using the air better than the leading car. Once it’s in the leading car’s wake, it has no air to work off of. Race cars, at high-level series, are set up specifically to use the air to go fast. The days of soft springs for grip are long behind us. Look closely at a Formula 1 car when it’s at a high-speed track: the suspension will never move. The cars we see in NASCAR races have their splitters just grazing the track, and it’s not a soft spring that’s doing that, it’s simply stiff springs with the nose set very low. This is very good aerodynamically, but horrendously bad when the air is removed. Furthermore, we see passes when, and only when, the trailing driver has the confidence that he can make the pass. If the car is sliding around, he may not be as brave and either plans a more careful pass, or makes no pass at all. Drivers say it’s fun to slide around, but if they lost a race because they slid around, they’re the first to complain about it.
DTM cars, with 2014 champion Marco Wittman pictured here, are the epitome of high-downforce full-bodied cars. Stepped splitters, diffusers, and more dive planes than can be counted keep them planted in all conditions.
Many series have gotten around this issue by leaving teams the luxury of high downforce but instead making the cars more efficient when trailing another car. We know that teams will get the downforce back somehow, that’s a given, so instead of taking it away, they just make it easier to get it. If we look at a splitter, which can be seen on almost every race car in the world these days, they usually all have something that is missing on the NASCAR vehicles: a diffuser. No, not a rear diffuser, but a front diffuser. Packed in underneath the front suspension but paired with the splitter, cars from DTM to Le Mans to even V8 Supercars all have a diffuser that takes the air under the splitter and uses it to make loads of front downforce. Some series go even further and create a flat-topped splitter with a curved underside, thus allowing the splitter itself to create downforce before the diffuser can do its work. Even my go-kart has a small diffuser under the front bumper.
NASCAR vehicles don’t have the diffuser, and instead either rely on a flat, angled piece of metal (radiator pan) or what they can get from vacating the front wheel wells for their front downforce. To be honest, there probably isn’t a more inefficient way to create front downforce, especially in a trailing situation. Add on to that problem a very small gap for the splitter to actually be effective, and it has no hope of working in trailing air. In fact, the splitter on a NASCAR vehicle will start to stall at the slightest hint of turbulent air. Can a driver see another car on track? If so, it’s probably going to reduce the downforce on the front of his car.
There’s so much that goes into aerodynamic updates that NASCAR just doesn’t seem to grasp yet. Yes, the Kentucky car existed, but it didn’t actually produce the numbers to say it was “better”. In 2014, the Kentucky race had 12 Lead Changes among 3 drivers, with no driver leading for fewer than 31 laps. In 2015, we had 13 lead changes across 8 drivers. But wait, there’s more! Of the 8, four only led for 1 or 2 laps, likely during pit cycles, and Denny Hamlin only led twice for 13 laps total. (Even more interesting: Brad Keselowski, who has been most vocal about cutting downforce, was the driver who led the most laps in 2014 with 199 compared to his 62 in 2015.) So we had, really, only four “meaningful” leaders in 2015 and 9 “meaningful” lead changes. True, there was a pass for the lead late, but it was with about 20 to go, and Kyle Busch was a few tenths faster, per lap, than Logano who couldn’t put up a fight at all. This weekend, we’ll see the “high drag” package hit the track. Will that work? I seriously doubt it. With a splitter as inefficient as the one they have in NASCAR, a 3″ spoiler extension is going to overpower anything done to the front end. Expect a lack of front grip in traffic, and whoever is in the lead will be tight.
Personally, I think NASCAR made a small problem even bigger by allowing the manufacturers to design the cars for the Gen-6. Wait, wait, don’t call me “an idiot” just yet, hear me out. We know that NASCAR is a high-speed type of racing, so every track is an aerodynamic track these days. Teams will always have downforce in mind when designing their cars and setups. The way the cars are now, they’re very good in clean air, but absolute garbage in traffic, and it’s simply because they’re inefficient in how they produce downforce. If we look at a lot of high-downforce racing like F1, DTM, Indycar, and Le Mans Prototypes in the WEC, we can see that the cars can follow one another at high speeds, despite producing extreme amounts of downforce by themselves. It’s because they’re efficient, and they don’t use brute force to create their aerodynamic grip. In fact, after the Indycar race in Fontana a few weeks ago, my Facebook feed exploded with people saying how amazing the racing was, and those cars are not lacking in downforce. Fact is, while NASCAR is interested in the racing product, the manufacturers may not be. They’re more interested in selling cars, so making their race car more identifiable is far more important than how it races. Because of that, the aerodynamic properties of the car, while considered, are not at the forefront of the manufacturer’s respective designers. NASCAR likely said, “It must produce [this many pounds] of downforce with [this many pounds of drag] at [this speed]”, and Toyota, Chevrolet, and Ford did exactly that, without considering how it generated those numbers. This approach is unique in the racing world.
Last year, I thought we were actually going to see something good hit the cars, and it was the “stepped splitter”. This has been around for years in racing, but not only was it tossed out of the NASCAR tests, it wasn’t even a decent design to aid in passing. If we look at high-downforce fendered cars, like the DTM above, or a Prototype, we can see the center section of the splitter is raised a bit. This raised channel feeds the diffuser behind it, and creates downforce. Unlike the NASCAR splitter, these raised sections can scoop up a lot of air, and can typically work in a somewhat turbulent air stream. Also, these cars feature the fender louvers, which simply allow any high-pressure air underneath the fenders to vent out of the top of fender. It’s very simple, but it produces downforce. On top of that, we see a lot of dive planes, which don’t produce a lot of downforce in their own right, but simply clean up air around the front of the car, allowing trailing pieces to be more effective in, you guessed it, dirty air. When NASCAR threw out the dive planes last year, I wasn’t surprised at that either, since there’s nothing on the car behind the dive planes to benefit from the cleaner air flow. Regardless of what NASCAR does to the cars, we’re going to return to what is currently the “norm”. Engineers and Aerodynamicists are smart, they’re going to find a way to get the cars to do what they want them to do, which is make lots of downforce simply because that’s the fastest way around the track. It happened with the COT, it happened with the downforce cut before 2015, it will likely happen with whatever package they introduce unless they make steps to make them more efficient in dirty air.
Brazil seems to have their “stock car” figured out. Here, former F1 driver Rubens Barichello takes his stock car around the track. Imagine if NASCAR had something like this!
Instead of doing anything like this, NASCAR mandated what is essentially a board on the front of the car and coupled it with another board on the back. Then they told the manufacturers to design the cars. If anyone had any hope of winding up with something decent, they were sorely mistaken. If NASCAR wants to really fix the problem, they can do one of two things. They can cut the bodies off completely, which would result in the lamest racing you’ve ever seen because all teams can get the maximum out of their tires. This wouldn’t be racing, so much as a parade of chassis all running the same speed in the corner. To fix the aerodynamics issues, NASCAR needs to realize that they’re a racing series, not a billboard for car companies, and design cars that can be raced around each other. The cars don’t even need to be street models. What if they used names that were either retired or just don’t exist? Chevy could do something like the Chevy SS-R, or Ford could bring back the Falcon name, and the Toyota gives new life to the Supra (why not?). Does anyone actually believe that manufacturers get a sales boost from their NASCAR vehicles? I’ve only seen one Chevy SS ever, and the Camry still sells just as well as it did before it was in NASCAR. NASCAR could say, “We require you to have a stepped splitter, vented fenders, a nose raked at this angle, a front diffuser with these dimensions, dive planes, and a rear spoiler like this.” The manufacturers, if they’re smart, could even turn the race models into high-performance street models. Plus, the cars could look pretty sweet and look like actual race cars again. If done right, we could have some stellar racing, cool looking cars, and still please the engineers who are stuck in the wind tunnel for 12 hours a day.
The opinions expressed are solely the opinions of the Author, and do not necessarily represent the opinions of iRacing or iRacing News.
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