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I am honestly surprised that they are removing the splitter.
Most of the complaints seem to be rooted in what fans have seen with the Cup cars and their splitters and not understanding that there are actually a bunch of other components under the car that also affect aero. https://twitter.com/RayEvernham/status/1288239009869725699
Most of the complaints seem to be rooted in what fans have seen with the Cup cars and their splitters and not understanding that there are actually a bunch of other components under the car that also affect aero. https://twitter.com/RayEvernham/status/1288239009869725699
The car might not turn out so well if all the components keep getting put to a fan vote.
I know that @RayEvernham is one of the smartest people in racing and know that he will figure out a way to make the car work well but he shouldn't have to redesign it because people are yelling online. https://twitter.com/CassieFambro/status/1288242478617972737?s=20
The "rework" part is what I was trying to get at. If anyone can build a car, it is Evernham but now he has extra work just because people online don't understand how aero devices work. https://twitter.com/ASturge21/status/1288242387274412032?s=20
But instead of just complaining, let's talk about Cup car aero and maybe more will understand that the splitter is not the only piece on the car that affects how it performs in the air. One of the better places to start is this article by
@drdiandra https://buildingspeed.org/2015/06/19/does-less-downforce-mean-more-lift/
@drdiandra https://buildingspeed.org/2015/06/19/does-less-downforce-mean-more-lift/
That @drdiandra article was a result of some of the rule changes and aero modifications in 2015 but it covers some of the main components and explains how the splitter is just one part of the equation as well as showing areas of pressure on the car.
https://buildingspeed.org/2015/06/19/does-less-downforce-mean-more-lift/
https://buildingspeed.org/2015/06/19/does-less-downforce-mean-more-lift/
I recommend that everyone read the whole article as it has an excellent explanation of not only how splitter size affects downforce but also how the adjacent components like the radiator pan come into play to help flatten the underside of the car to increase downforce.
As mentioned in the article, the length of the splitter will affect the downforce which is why NASCAR changes that dimension when it wants to change how the cars behave but there are still trick that can be done to optimize even if length is changed.
The angle of the splitter is often measured down to a fraction by the teams because even though the bottom of the splitter is flat, the teams can angle it slightly in order to create a diffuser effect with it which helps with downforce and changes pressures slightly.
Once the air moved past the splitter, it hits the radiator pan or as NASCAR calls it in the rule book, the "splitter extension panel."
This is a flat piece of metal that sits under the car and helps to flatten that surface behind the splitter.
This is a flat piece of metal that sits under the car and helps to flatten that surface behind the splitter.
Yes. The best teams are the ones that figure out how to get that angle and optimize those pressures while keeping that required flatness. https://twitter.com/sfrymyer2/status/1288251520056786945?s=21 https://twitter.com/Sfrymyer2/status/1288251520056786945
Josh is over here out-screenshotting but this is a good segue. The pan pictured above is just and example. The current one has fences and is longer as you can see by the schematic. https://twitter.com/joshahamilton/status/1288251575857754112?s=21 https://twitter.com/joshahamilton/status/1288251575857754112
Now you might be wondering how a flat piece of metal underneath a car could suck it down to the ground and for that we have this great demonstration by @Brian_Murphy_ https://twitter.com/Brian_Murphy_/status/1088140614057762822?s=20
A better view of the size of that radiator pan.
An important distinction is that even though things may look the same from the outside, the underside of the car may change for different track types. https://twitter.com/Brian_Murphy_/status/1288253462145368065?s=20
NASCAR mandated the dimension of the radiator pan but much like the splitter, teams try to play with the angle of it in order to optimize pressures below the car and some very crafty teams have even figured out how to make it change shape when a car is under load.
Now those are all fairly well known tricks but the real smart teams make the rest of the components become part of that radiator pan to create a huge flat underfloor. This might be confusing at first but you have to consider all of the components around the radiator pan.
If we look at the splitter structure we can see where the radiator pan would go behind it but we also see the gaps where things like suspension components end up and those are opportunities for aero modification.
Remember how I said that NASCAR engineers rival Formula 1 engineers. Well, this is one of those times. The smartest teams design the components that are adjacent to the radiator pan to lower down at load and create a flat extension beside the pan which results in wider flat area.
The general idea here is that there is more to downforce than meets the eye even if we're just looking at the front of the car and even if we dig into the underside, there are lots of areas to exploit if you have smart people working on it.
This is all without even getting into stuff like the fender wells and how optimized designs will pull air out of the engine bay to create a low pressure area under the hood and even then we've only covered the front portion of the car.
A better view of that area near the radiator pan that can be exploited can be seen in these diagrams of the front subframe, crossmembers and supports.
In addition to those pieces, we can look at the engine and specifically the oil pan. You can see here how the flat bottom of the oil pan can act as another flattened extension to complete that flat floor at the front of the car.
The whole idea is that although NASCAR may mandate certain measurements for pieces like the radiator pan, top teams will figure out how to make them bigger by making the pieces beside them become part of that flat area when the car is at speed.
While changes on Formula 1 cars are often complex and also apparent because they are visible, NASCAR engineers are just as creative when it comes to aero but the parts are usually hidden away underneath the car so we don't get to appreciate them as much. https://twitter.com/ScarbsTech/status/1278988047162527746?s=20
Hopefully this helps some to understand that it's not all about the splitter even though it often gets a bunch of attention and is also another example of what sets the very top teams apart.
Ran into one more picture that kind of brings all of the pieces that I discussed above together so you can see where the oil pan, crossmember and so on are in realtion to the body.
Now if someone wants to send me a picture of the underside of their NA18D car that would be really cool.
Teams definitely work on the oil pans because they have significance for aero as well as moving weight around. https://twitter.com/skejas/status/1290778994246406146?s=20
It's not the most clear but video from the Preece crash at Kansas shows us a little of how teams modify the underside to be flat.
The splitter and radiator pan have been ripped off here already but what we're really interested in is the area behind them.
