2017: Clean Air Is NOT King... Speed Is King

Although this video is about overtaking in F1, a lot of the aero concepts apply to NASCAR as well because the overall enemy is the same, dirty air.



Specifically, his points #1 and #4 really blew my mind. First, a lowered wing (or in NASCAR's case the spoiler) naturally dumps it's dirty air closer to the front splitter or wing, thus causing more turbulence for the trailing car. Now, in the case of a spoiler a lower height also reduces downforce, which isn't the case with a wing, so overall dirty air is still probably lowered as the spoiler goes down, but not as much as it could be. If there is a limit to how short the spoiler can be cut without unbalancing the car, and I think we're getting close to that point, maybe the next step is to somehow raise where it is mounted so it affects the trailing car less. The Gen 5 wing doesn't look so bad now does it?

The 4th point he makes is pretty much straight counter to the prevailing wisdom on this board, that is more horsepower=good for passing. The problem when we say that is we aren't considering the meta game of aero development, specifically the balance between downforce and drag. What we've seen in F1, and I would believe this is true in NASCAR as well, is that as power goes up the balance shifts in favor of downforce over drag. Thus, because cars have more power, aero engineers are able to put their talents more towards increasing downforce and are less concerned with increased drag because the cars are better able to overcome it. When power is cut the opposite happens; engineers build less downforce into the cars because the drag penalty isn't worth it. So if we want the cars to be slicker, less downforce dependent, more power isn't the way to go. Irrespective of the NASCAR mandated aero package, we've seen teams make huge gains building the cars towards one objective or the other, there's only so much they can control ATM.
 
Acs said:
Keep in mind, the cars are supposed to be making about 1500 lbs of downforce now with this new package, which is the same amount they were at the start of 2016 before teams clawed it back. So you'd think we would see a similar great race to last year, but no. Something didn't go as planned with this aero package.
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I don't think that is correct, according to the numbers I have seen. The 2016 rules subtracted about 900 pounds, the best estimate I've seen for "claw back" is 100 pounds, and 2017 rules took off another 500 pounds. I believe current downforce is substantially lower than last year, and lower than we have seen in multiple decades of cup racing. Yeah, I have heard various non-specific reports about the engineers working to gain back most of what was lost, 75% of what was lost, etc. But these comments lack credibility IMO. I would be interested in any reports of actual wind tunnel measurements, however. Has anyone seen actual wind tunnel measurements from the 1980's or 1990's? We know there were substantial increases in downforce, and reductions in drag as well, between the 80's and the 90's. I'd love to see the numbers.
 
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dpkimmel2001 said:
His average speed unrestricted @ Talldega was just over 216 with a top speed of 228 at the end of the backstretch. They said at the time that given a little time to tweak the package, they felt they'd hit about 235 mph. At the time, 216mph was 20-30 mph faster than the restricted car.
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I recall seeing an article a long time ago about Indycars hitting 240 at California. The point of the article is that a driver at that speed doesn't have enough time to react to an accident at the other end of a straight. There probably is a practical human speed limit in racing.
 
dpkimmel2001 said:
His average speed unrestricted @ Talldega was just over 216 with a top speed of 228 at the end of the backstretch. They said at the time that given a little time to tweak the package, they felt they'd hit about 235 mph. At the time, 216mph was 20-30 mph faster than the restricted car.

As far as taking flight today if they were unrestricted..... I think there's little doubt that they'd take air once they turned sideways or backwards.

There is no way in heck we are ever going to see them running unrestricted at those high speeds around those venues.
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Buy the NASCAR expansion pack for Forza motorsports 6, which is a fairly accurate sim, you can experience this for yourselves. They have the 2016 cup cars, Daytona oval, and both the 2016 tapered spacer engine and even the pre-2015 engine without a tapered spacer, which makes over 900 hp. With the right setup people are doing at least 235 constantly, just like they said in 2004. And that's alone, not even in the draft. Plus with the amount of downforce cars make today they are still flat-out even at 235... meaning there's still more speed to be had at Daytona if there was more power. Yeah, no, the plates aren't coming off at Daytona and Dega. The racing style that everyone seems to hate wouldn't change besides the cars going 50mph faster with all the associated dangers.
 
Question for all: How many people would be in favor of an rules package that creates an aero DISADVANTAGE for the leading car, and the trailing car would have an advantage in passing (even if he was not the faster car in clean air)? Many people don't like it when the faster cars get to the front and stay there, so how about a situation where they are no longer faster once they assume the lead?
 
LewTheShoe said:
Question for all: How many people would be in favor of an rules package that creates an aero DISADVANTAGE for the leading car, and the trailing car would have an advantage in passing (even if he was not the faster car in clean air)? Many people don't like it when the faster cars get to the front and stay there, so how about a situation where they are no longer faster once they assume the lead?
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I would not be in favor of that.
 
LewTheShoe said:
Question for all: How many people would be in favor of an rules package that creates an aero DISADVANTAGE for the leading car, and the trailing car would have an advantage in passing (even if he was not the faster car in clean air)? Many people don't like it when the faster cars get to the front and stay there, so how about a situation where they are no longer faster once they assume the lead?
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I have no problem with the fastest car getting out front and running away. There's always competition somewhere in the field. Must just be me.
 
LewTheShoe said:
Many people don't like it when the faster cars get to the front and stay there, so how about a situation where they are no longer faster once they assume the lead?
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You're making a leap here. What's to say that the leading car wouldn't still be faster due to superior handling, driver skill, whatever, despite the aero disadvantage of being in the lead? Or are you proposing something that so greatly penalizes the lead car that it overcomes all advantages in the other categories? Because even I wouldn't be in favor of that. Realistically, I do not want to see the lead car have any aerodynamic advantage over the trailing car. If at all possible, I'd like to see the lead car have no disadvantage either. But because it's impossible to nail that balance dead-on, I would be ok with a slight disadvantage aerodynamically to the lead car. Not so much as to make it impossible to hold the lead, but enough to force them to play defense if a trailing car comes up on them.
 
LewTheShoe said:
Question for all: How many people would be in favor of an rules package that creates an aero DISADVANTAGE for the leading car, and the trailing car would have an advantage in passing (even if he was not the faster car in clean air)? Many people don't like it when the faster cars get to the front and stay there, so how about a situation where they are no longer faster once they assume the lead?
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I think most people would like to see Nascar use cars and tracks where aero is mitigated as much as possible. I won't have to worry about a clean air, side drafting or dirty air this weekend and I will really appreciate that.
 
Way back when this is the only Aero I was familiar with and I liked it that way. The Canucks will know what I mean.

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VaDirt said:
This. Those damn splitters are so close to the ground now, anything kills em. Hell, the "pass in the grass" (which wasn't actually a pass, but I digress) could not happen today.
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Are you in favor of reducing more HP?
 
Zerkfitting said:
I recall seeing an article a long time ago about Indycars hitting 240 at California. The point of the article is that a driver at that speed doesn't have enough time to react to an accident at the other end of a straight. There probably is a practical human speed limit in racing.
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They still go that fast. Not Gil de Ferran at Fontana average speed fast but watch Fast Friday and qualifying at Indy in two months when they're at full boost and you'll see top speeds like that. Last year I saw the fastest cars, the Andretti cars, hit 241 MPH before diving down into turn 1.
 
Acs said:
Realistically, I do not want to see the lead car have any aerodynamic advantage over the trailing car. If at all possible, I'd like to see the lead car have no disadvantage either.
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What I've seen this year quite frequently is trailing cars choosing to run precisely in the track of the car they are chasing. But Fontana and Atlanta are wide multiple groove tracks. This makes me think the leader has little, if any, aero advantage. If he did, the trailing car would choices a different lane. So I think we are close to thd balance you described.

I liked the races we have had this year just fine. I'm heavily into a high degree of difficulty and the winner being based on merit. It wouldn't seem right to me to saddle the leader with an aero penalty. I'm hoping those who didn't like these races will comment on what would make them better.

BTW, I appreciate your thoughtful contributions on the subject. I'm still trying to digest the F1 video...:rolleyes:
 
Skoalbandit33 said:
I think most people would like to see Nascar use cars and tracks where aero is mitigated as much as possible. I won't have to worry about a clean air, side drafting or dirty air this weekend and I will really appreciate that.
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As I said in my prior post, I think we at close to what you say "most people" want. But I'm hearing a lot of complaints about the races. I liked them, however. BTW, aerodynamics has played a major role in Nascar racing since before I followed the sport (early 1960s). If we could magically remove aerodynamics from Nascar, it would be dunbed down like hockey without a goalie. JMO.
 
LewTheShoe said:
As I said in my prior post, I think we at close to what you say "most people" want. But I'm hearing a lot of complaints about the races. I liked them, however. BTW, aerodynamics has played a major role in Nascar racing since before I followed the sport (early 1960s). If we could magically remove aerodynamics from Nascar, it would be dunbed down like hockey without a goalie. JMO.
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I have said repeatedly that you cannot get rid of aero but the object is to mitigate it as much as possible. We put man on the moon nearly 50 years ago so mitigating aero through the use of a proper car on proper tracks doesn't seem to be a big ask. In fact I am sure Chad Knaus already knows how to fix it!

IMO the problem is that Nascar has gone too far down a rabbit hole to retreat and do things properly so they find themselves in a position of adding band-aids that quickly fall off and then need to be reapplied. From a business standpoint I understand where Nascar is coming from as fixing things properly at this point not only would not add a single fan but wouldn't even slow down the mass exodus of people from the series. Why spend money on a leaky ship if everyone is jumping off to safety?
 
NASCAR may have a lot of power in terms of what to put in the cars to make them drive a certain way.. but no matter what they do the cars will always punch a hole in the air and create turbulence.. You ever been driving down the highway and get passed by a car and feel the car move? Now imagine you double or triple your speed and drive even closer to him.. It's not hard to figure out why dirty air does what it does.. it's physics.. no matter how these cars are setup that won't change. Sure they can help the effect it has.. but driving behind another car is always going to affect the car behind at those speeds.
 
I'm wondering how feasible it would be to open up the hole in the restrictor plate and at least increase the speeds a little bit. There's no doubt these cars top out much higher before corner entry at Michigan and Fontana and higher at places like Texas, Charlotte, Kansas, Las Vegas, and probably Kansas too. The difference is the speeds aren't sustained through the turns at those tracks. So why are we content to let them barrel into the turns at such high speeds? Why are Daytona and Talladega restricted to a constant 195-200 range whereas elsewhere we might see 205-220 at certain parts of the track?
 
2 Sweet said:
Why again did they reduce horsepower a couple years back? What was their goal?
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I remember reading that part of it was due to cost cutting that would be induced by making parts last longer. I haven't seen any evidence of that yet but if anyone has I'd like to check it out. I believe the tapered spacer (which was pushed by Ford) won out as an alternative to an all-new 5.0L engine (being pushed by Chevy and Toyota) because the cheapest option would be a reduction on the intake side. But, Tim Cindric also said that with HP reductions usually come increased costs since the finer details become more important as each incremental bit of power becomes more significant. So things probably cancelled each other out or just made things more expensive.
 
SlicedBread22 said:
NASCAR may have a lot of power in terms of what to put in the cars to make them drive a certain way.. but no matter what they do the cars will always punch a hole in the air and create turbulence.. You ever been driving down the highway and get passed by a car and feel the car move? Now imagine you double or triple your speed and drive even closer to him.. It's not hard to figure out why dirty air does what it does.. it's physics.. no matter how these cars are setup that won't change. Sure they can help the effect it has.. but driving behind another car is always going to affect the car behind at those speeds.
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Try driving a KLR 650 behind a Semi on the Interstate! You are doing more bobbing and weaving than Mohammed Ali did in his prime.
 
FLRacingFan said:
So why are we content to let them barrel into the turns at such high speeds? Why are Daytona and Talladega restricted to a constant 195-200 range whereas elsewhere we might see 205-220 at certain parts of the track?
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Because like you said, they are only at those extreme speeds at certain parts of the track, and that part of the track isn't as dangerous as others. If at Michigan the cars were able to carry 220 through the corners, there would be horrendous wrecks and we'd have to put plates on there too. But as-is the top-end straightaway speed isn't nearly as dangerous as mid-corner speed. Example: Joey Logano's car can survive being bodyslammed by the #18 even when doing 195 because they were going straight down the back-stretch. Kyle Busch's car completely lost control after a small bump from the #22 even though they were only going 160, because they were in the middle of the corner already at the limit of grip. The limit of grip through the corners depends on a lot of things like banking and downforce, but it is no doubt much higher at Daytona and Talladega than at even Michigan or Kansas. Cars can withstand a little bumping and contact through the corners at the plate tracks even at 200mph because that limit of grip is somewhere north of 230mph.
 
Acs said:
Because like you said, they are only at those extreme speeds at certain parts of the track, and that part of the track isn't as dangerous as others. If at Michigan the cars were able to carry 220 through the corners, there would be horrendous wrecks and we'd have to put plates on there too. But as-is the top-end straightaway speed isn't nearly as dangerous as mid-corner speed. Example: Joey Logano's car can survive being bodyslammed by the #18 even when doing 195 because they were going straight down the back-stretch. Kyle Busch's car completely lost control after a small bump from the #22 even though they were only going 160, because they were in the middle of the corner already at the limit of grip. The limit of grip through the corners depends on a lot of things like banking and downforce, but it is no doubt much higher at Daytona and Talladega than at even Michigan or Kansas. Cars can withstand a little bumping and contact through the corners at the plate tracks even at 200mph because that limit of grip is somewhere north of 230mph.
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I would think that the speeds carried into the turns at those places would carry a ton of risk even compared to a Daytona or Talladega type. Those tracks have a lot of loading on the RF tire and when that goes right when you start to turn it can get ugly in a hurry. Same thing when you get to the end of the straight at one of those places and then you find out you have no brakes left. The Fontana Radioactive this past week seemed to have an unusual amount of complaints regarding brake wear, which I guess makes sense considering how much more these guys have to slow down with less drag on the straights and less downforce for the turns.
 
FLRacingFan said:
I would think that the speeds carried into the turns at those places would carry a ton of risk even compared to a Daytona or Talladega type. Those tracks have a lot of loading on the RF tire and when that goes right when you start to turn it can get ugly in a hurry. Same thing when you get to the end of the straight at one of those places and then you find out you have no brakes left. The Fontana Radioactive this past week seemed to have an unusual amount of complaints regarding brake wear, which I guess makes sense considering how much more these guys have to slow down with less drag on the straights and less downforce for the turns.
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I agree with you. It's not that those kind of corner entry speeds are really safe, just that the overall track is acceptably safe without plates because the mid-corner speeds are much lower. But if you take off the plates at Daytona you would have all of the same issues as you described except at far higher speeds. Not good.
 
LewTheShoe said:
Question for all: How many people would be in favor of an rules package that creates an aero DISADVANTAGE for the leading car, and the trailing car would have an advantage in passing (even if he was not the faster car in clean air)? Many people don't like it when the faster cars get to the front and stay there, so how about a situation where they are no longer faster once they assume the lead?
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Back when they had mostly stock bodies and they were first understanding aerodynamics, the leader was frequently pasted by the car behind. Drivers wanted to be 2nd or 3rd starting the last lap to draft past the leader (Indycar announcers called it slipstreaming).
 
I guess another way of putting my views is thus; the whole strategy of running a NASCAR race boils down to track position vs speed on the race track. That should be an either/or, a tradeoff that must be balanced. The leader having an aero advantage completely invalidates that, because with these highly sensitive cars an aero advantage>all other factors, and that makes them faster. Put it another way, track position shouldn't also get you speed on the racetrack. That needs to change.
 
aunty dive said:
Hold race speeds where they are / keep the cars on the ground.
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If they really want to keep cars on the ground, they'll get rid of that stupid underhang at the plate tracks. It catches air, just like the wing did.
 
aunty dive said:
He's talking acout the rear bumper cover.
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Thank you. Even getting rid of that will probably not prevent cars from getting airborne. I'm unsure of the exact details, but I recall an "expert" in the field of aerodynamics mentioning something along the lines of...as long as a car is traveling at least 175 mph, there will always be the chance for these cars getting airborne if they get abruptly turned beyond a 90 degree angle.

We see this happen occasionally at non-plate tracks and the cars stick to the ground. I think the primary reason for this is because at those tracks, there is no "umbrella" effect (Jeff Gordon's words) due to the field being strung out. The air wake created at Daytona and Talladega is so strong that it essentially creates an updraft that is stronger than you will see with most severe thunderstorms that create tornadoes. Try imagining this as an experiment: Be a few feet above the backstretch at Michigan during a normal green flag run and drop a feather. Odds are that the feather will flow gracefully and consistently forward as the cars pass underneath it. Now try it at Daytona or Talladega as the pack of cars go by. The feather will likely bounce around and float upwards due to all the turbulence. That is similar to how the cars behave when they get abruptly turned at those tracks.
 
LewTheShoe said:
Clean air was definitely king right up through 2015, and also 2016 at single-groove tracks. But this year... not the case. We'll see what happens at repaved tracks like Texas and Kentucky, but so far there has been no aero-induced impediment to passing the leader.
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And the trend continued at Texas... speed was definitely king. The groove was narrow due to the repave, so clean air was a thing, but speed was king. There was a ton of passing, and the top finishers came from deep in the pack multiple times. Jimmie Johnson was just *barely* faster than Logano at the end, but he was able to get by for the win. Under 2015 aero rules, the 48 would have been unable to get close enough to pass the 22, and would have followed the 22 to the end IMO.

The preferred passing technique was to track directly behind the car in front, close up behind him taking the air off his spoiler, and get him loose. This was as close to aero neutral between the leader and the chaser as one could ask for IMO.

Glad I took the time to watch this race again, as it was better than I realized. In real time, I was too concerned with how my guy was doing to realize what a fine race this was.
 
Bristol... check.
Richmond... check.

Clean air has never been a really big deal at these short tracks, but the low downforce rules in place this year have definitely improved the racing, and upped the degree of difficulty. Fascinating to watch the cars sliding around as they come off the corners.

Talladega does not apply to the subject of this thread. I hope Kansas and Charlotte continue the trend. Good racing, really good racing, so far in 2017... :)
 
Kansas... check. Speed was KING.

I watched the race again last night, and did not detect any aero influence preventing a quicker car from passing the leader. Time and again, the 78 went by leader 21 to take the point. Blaney had the best short-run speed, the best pit crew, and the #1 pit stall, so he started several runs in front. But after 15 or 20 laps, Truex gained speed and made the pass as Blaney's tires fell off.

The 2017 aero rules are working perfectly IMO, and are contributing to thrilling racing, along with good tires that have significant falloff at most tracks. And the drivers are working, really working, to maintain control at speed. Charlotte in the World 600 will be a big test, because this track seemed to epitomize the clean-air-is-king problem in 2015... a slower lead car could hold off quicker guys who had to run in dirty air. But that was 2015... so we'll see next week.

PS - The most perplexing performance in Kansas was the 18. Kyle Busch was badass fast in the first half of the race, whether at the front or back in traffic. But just the opposite in the second half... lackadaisical speed whether leading the race or in traffic. He still was a top-10 car, but not a threat to dominate as he had been earlier. But this was not an aero issue for the 18. I guess they just lost the handle.
 
Handling had something to do with Truex's win which could be part of the speed equation. Being able to run the bottom line took most of the aero out of the equation. I don't think Truex was out motoring Blaney. Blaney couldn't carry the speed thru the corner that Truex was able to after his tires warmed up. Blaney until that last restart had a huge lead in clean air over Truex who got hung up in the pack Truex was so far back he couldn't catch any draft to catch up. Clean air is always going to be an advantage. Nascar with this latest package has enabled handling to come into play, progressive banking for multigroove racing
 
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