This is a good video, but the top speed of a car is not increased by a wing or spoiler, it makes it more stable at high speeds, but the drag it produces slows the car down slightly, but the grip to the road is increased.
@@iulianborta What do you mean by overall speed? If you are talking about the speed a car can take through turns, then yes, more grip will allow the car to go faster around a corner. I am talking about the top speed of a car, which of course means in a straight line. More grip does NOT increase straight line top speed, because the car won't be at risk of losing grip when going in a straight line at top speed. (Unless the car is super unstable for some other unrelated reason) This is not something I have come up with myself by the way, this is common knowledge as you can see in several other comments on this video. In all forms of car racing you have to decide how much straight line speed you want to sacrifice to increase corner grip using spoilers.
+Nathan Enders I do the same only on short runs. Longer ones...because of the downforce I stress my neck and then I have to stop earlier at the massage shop.
NOOO, how does increased downforce increase acceleration? spoilers create downforce and drag, not HP. given that, we see that aerodynamically these spoilers would be a disadvantage in a straight-line race. The only time the increased downforce would be useful in this situation is at the beginning of the race, where improved traction would also increase acceleration. BUT, at the beginning of the race, the car is moving slowly and thus, so is the air moving over the spoiler, making it useless. By the time the vehicle is moving quick enough for the spoiler to come into notable effect, traction would no longer be an issue. At this point, all forces of the spoiler become a disadvantage. More drag, more mass (them weight savings, bro,) and of course, the downforce would make it more difficult for the car to accelerate as well.
+T.B. Squad Absolutely. I think this guy sells spoilers and wings on the side. I don't think he ever mention weight, and he sort of presented a drag race of sporty cars. The blue car would win.
Rama Kant increased friction force, on its own, is not a factor for increased acceleration. increased friction force would only be an advantage when the amount of traction is not sufficient for the power of the car. As speed increases, the amount of friction force needed to maintain grip for a given power level actually decreases. Extra downforce = extra weight = extra friction. the increased weight and friction become a MASSIVE disadvantage as the car increases speed and their effects are increased. Like i said, at slow speeds, the car could benefit from additional friction/traction as the initiating friction force also has to deal with inertia of a car that is still. HOWEVER, at these speeds the spoiler/wing does not have enough airflow over it to for it to work. its an "aero" part; its force, by nature, is directly related to the speed of air moving over it. so, at high speeds, when the spoiler comes into effect, the car can maintain grip without any increase of friction force, and therefore, its useless. friction hampers speed. that's simple physics man.
Rama Kant lol. ok so, friction is not causing the car to move or accelerate ON ITS OWN (I did say that.) a mechanical force is needed for any type of movement, first and foremost. In this instance, the engine. Now we get to the friction part. newton's second law is saying that a force applied to an object is proportional to the speed of its acceleration. FRICTION IS NOT THIS FORCE. the force applied is the rotation of the tires, which is an INdirect translation of the engine's force (we'll get to that later,) which THROUGH friction causes acceleration. example: my cousin used to own a prius; when he floored it, it couldn't spin the tires. Now, if he were to use a stickier compound of tire, would he be able to accelerate quicker because there was more friction? no. the friction is merely what transfers the force of the engine to the road's surface, which is the force you would use in newtons second law when referring to this example. ok, on to the amount of grip needed at a given speed and power level. When the mass of a car is stationary, inertia dictates that it will want to stay stationary. therefore, the amount of force needed to "initiate" the acceleration is greater than if it were already moving. The force of inertia is directly related to the speed in any given direction of the car. Now, in first gear, the ratio of force applied from the engine to the tires is very high, meaning that a high level of traction is required to convey that force. as the gears go up, the force conveyed to the tires decreases, and proportionately less traction is needed to maintain grip. (the force is now in present in the form of speed.) Now on to your mass/weight argument. As a spoiler produces down force, it is increasing the WEIGHT of the car, but not the mass. I mean, bloody hell, man, the shit is called DOWN. FORCE. its a force that's downward. of course its added weight. weigh a formula1 car at a stop and it'll weigh 1/2 as much than if you weighed it at 180mph (assuming you could.) And, because the added weight is directly proportional to the speed of the vehicle, the added traction is only having an effect on the car when it's not even needed (In higher gears where we see the force of the engine in the form of speed, rather than torque.) THEREFORE, as i have just proved through the laws of physics, every aspect of a spoiler in the instance of straight line racing a 370z is a disadvantage. I suggest you know basic physics before trying to talk condescending to someone who is clearly wrecking you right now, "sweetheart."
+T.B. Squad Dude everybody knows friction doesn't act on its own , it needs a stimuli. "a mechanical force is needed for any type of movement".Correction: not just any force but an external force.Which in this case is friction . Well on your first gear argument, you're right except that you're missing this: During launching the car needs to overcome the static friction; which is a lot more than the kinetic friction which acts under motion, thus u need less driving force at speeds to overcome friction and more force/torque at the beginning. The value of kinetic friction doesn't change much with speed(depends on a lot of things, it might increase/decrease, but only by a meager amount).So you cannot say that as we speed up friction requirement reduces.Because its basically the traction force. Moreover all your arguments are based on the fact that the car is not experiencing any lift while moving at high speeds. The air flow under the car is laminar in nature while above the car is turbulent causing a high pressure zone under the car and low pressure zone above it. Thus causing lift . We need that downforce to overcome the same. Bugatti Veyron moves at speed higher than the ones required for take off. Had there been no spoilers on it, she wouldn't have been able to do so. I hope you get the reason of using spoilers which is still the same as in my previous answer : better traction which can be achieved either by increasing the normal force(use of spoilers/wings) or the coefficient of friction( using better compound tires). P.S. In the language of physics that extra weight is called load or the 'apparent weight'. Go clear your concepts kid!. Then try condescending someone else.
+Rama Kant the force of the engine acts through the rotation of the tires, which require friction to cause movement. But, you seem to be under the misconception that an increased friction force will directly relate to an increased acceleration force. back to the prius, we see this simply isn't true, static friction versus kinetic friction doesn't apply because the tires aren't sliding... kinetic friction applies to objects that are sliding against one another. So, i can very well, and scientifically accurately say that as we speed up, friction requirement is reduced because of the gearing (as i already explained.) a great example would be my 335i. It can spin first and second gear with ease, but in fourth, even if i have the engine at optimum rpm, it would not be able to spin the tires. The amount of torque applied to the tires versus what gear is being used is actually very dramatic. so much so, that even in second gear, i'm not entirely convinced the 370z in question would be able to spin the tires given a dry road surface, much less higher gears like 4th or 5th, where we would see the effects of the spoiler come into play. Lift would actually be beneficial, up to a certain point, if you're looking for pure acceleration, because load = weight. "Whats the load capacity of that truck..." If you apply a downward load on something, it will weigh more, regardless of what you want to call it. less weight = better acceleration, given no other factors. i'm sure we can agree on that much. We know a 370z will not take off within it's top speed. So, the Bugatti reference is almost entirely irrelevant. Every racing team knows the basic formula: you want to go faster in a straight line? reduce downforce. REDUCE IT. want to go faster in the twisties? add downforce Idk what argument you even have that i haven disproved anymore. for an english major, i think i'm doing pretty good, considering you've got nothing left going for your notion that spoilers increase acceleration.
Kids, or anyone came here thinking you are about to learn stuffs: the aerodynamic part of the theory is basically incorrect. It doesn't work like that.
+SVAFnemesis I have to agree. And I believe the results of the "race" are wrong. In a straight line race (as represented), the weight and drag of the spoiler or wing, are going to slow the car more than any advantage gained. Supercars on a track with many turns, sure. F1 cars on an F1 track, of course. But street cars, even sporty ones don't spin tires except in 1st heat when the speeds are too low to provide downforce.
Spoiler will not necessarily give higher top speeds. Take F1 for example, as you increase angle of the rear wing, you are increasing the downwards force, but you are also increasing drag which actually reduces top speed, so for tracks like Monaco, you would want a greater wing angle, but Spa you would decrease it because of fast corners.
eclipse245 The relative difference will change though. The effect on a car that is 2 feet with a one foot wing versus a 4.5 foot honda civic with a one foot wing... The relationship of the coefficient of drag will change with respect to each car differently. It's like saying if you gain 10% drag, which one has more drag. It depends on the starting values. And F1 has a lot of R&D into their aero designs
DareDevil5692 The one foot wing generates the same amount of drag regardless of the height of the car. The main argument though was that spoilers make you faster in a straight line, which is false.
eclipse245 Perhaps I did not type clearly, yes a one foot wing, same drag. But a car with no drag (just saying for simplicity sake) plus one foot wing or a car with average car drag plus one foot wing is different. If the spoiler adds minimal drag to your mini van, honda civic or whatever but substantial drag to your aerodynamic race car, then it will be different. Also the air fed into the wing will be different on each set up. It will depends on more than just a pure drag figure Now a spoiler that decreases the wake zone will make you have less drag, but a wing that gives you down force only helps if you do not already have enough traction. For example, you shift into 3rd or 4th gear at ~100 mph and roast the tires, downforce would help your traction and therefore make the car faster by letting you put more power down to the ground assuming its not so un-aerodynamic that it cannot go any faster. But for most cars it doesn't matter because that's not the case. A wing in 1st and 2nd gear will have no effect on traction and that is where it's most important in a drag race... We both agree that the video is wrong and it is oversimplifying the situation. It was these blind oversimplifications and focus on pure theory that lead me to turn MIT down when looking for colleges. It's just not as applicable in real life where we all live.
Wow very good, I hardly ever see explanations so accurately explaining boundary layer flow types, airflow separation and pressure drag. Also awesome effort with the wind tunnel. My main complaint for accuracy though is that in downscaling with models you introduce the effects of low Reynolds numbers. But still great job.
Ok I have to make some assumptions here. First, air is at 1 atm at 300 Kelvin (26.85 °C) with a kinematic viscosity of v=1.568EE-5 m^2/s which is 2.43EE-2 inches^2/s Porsche is assumed to be 1999 model, therefore 51.4 inches /20 for scale so 2.57 inches tall. If you pause at 5:12 and make your best guess as to the height of the box. Which is roughly 2 times the height, so call the box 5.14 inches => 5.25 inches for ease of calculation. The length is 175 inches / 20 for scale = 8.75 inches. (8.75/5.14)*5.25 = 8.937 = L inches (so it’s scaled properly) Re=(Q*D_h)/(v*A) where V is fluid velocity, D_h is hydraulic diameter, v is kinematic viscosity, and A is cross sectional area. D_h= (4*A)/P where P is the perimeter the fluid contacts. If W=H because it’s a square, A is W^2 which is 5.25^2=27.5625 in^2 and P=20.5 inches. D_h= 5.25 inches (I know it’s weird it worked that way.) Ok here’s the final assumption, Q. Q is the flow rate in the pipe. For that we have to assume a volume of fluid. Let’s use the length of the car, L=8.397 inches. If you analyze the footage closely around 5:09, you can see that the smoke flows under the car from the front to the rear in about 0.5 seconds. Q=V/t Where V is volume of air (A*L) = 246.333 cubic inches of air (roughly 1.064 gallons or 4.04 liters). So therefore if t=0.5, Q is 123.167 cubic inches per second. Re= (123.167 in^3 * 5.25 in)*s/ (0.00243 in^2 * 27.5625 in^2) *s Re=9,654.5 call it 9700. Reynolds numbers of 10^4 magnitude are considered below standard low Reynolds number aerodynamic flow (usually the 10^5
@@TGears314 246/0.5 is not 123, but 492, so the Reynolds number should be 4 times bigger I guess. That would put it closer to the right range but still too low, which I feel is correct because the "wind tunnel" in the video does not seem right. Strange they didn't think about this if we're right.
Can't watch a video like that. The beginning is wrong. In a straight line the car without spoiler would win. Add corners, than the "spoiled" car would win.
At low speeds, they will be nearly unaffected by aero. but at any given speed, the car with the spoiler does have more downforce and is capable of putting more power down to road. Straight or turning is irrelevant if all aspects are the same except for the spoiler. Edit: After re-reading your comment, it looks like you are thinking in terms of top speed and in that aspect you would be correct. How I understood the video was acceleration rather than constant throttle
The issue with this video is that is incredibly vague and gives an overly simplistic overview to drag, which is creating a lot of open ended questions like this, where everyone is using hypotheticals to prove "their" point.
we are just comparing different situations and learning from them though. If any of them is wrong please tell. Nevertheless i agree with you, the video lacks of many considerations that need to be taken into account
@@DevonLadd it depends on what you're doing if you track race it, you want a good amount of downforce and minimal drag if you're straightline racing it, you want to reduce drag without downforce
Actually the car with the lowest drag would win in a straight line, but the cars with higher down force in the corners due to better cornering and traction.
Straight line speed is affected by a rear spoiler; its drag interferes with its Vmax . E.G the original Countach (no tail spoiler) was 10 mph faster vs the later Countach (BIG tail spoiler). Increased cornering performance and high speed stability is the main reason you would fit a spoiler.
Spoilers in some cases can actually reduce drag. They can ensure that the flow has a clean separation at the rear of the car reducing vortices which would otherwise increase drag. Also your race example is misleading a rear wing wouldn't generate downforce when needed at the start of the race but it would produce drag when it's not needed at the end.
Yes, you are exactly right. It's a shame that racing organizations outlaw airfoils that are adjustable during the race. Minimal angle of attack in the straights, steep angle during braking, and mid angle through a turn. Since you are a motorcycle guy, I've always thought front and back wings on a bike would work, but the mounts would be complicated. The wings would need to be close to the ground, and pivot as the bike leans into turns.
There is a limit on adjustable wings and spoilers because , as you can imagine, a car following another that pulls out the full 'flaps' would practically blind the driver behind. ... wait did I just write that O_o godz oh well once seen, can't be unseen.
I think you've made some big mistakes here. You claim that a spoiler increases drag and adds downforce. While the downforce undoubtedly improves cornering performance, the drag will most definitely DECREASE acceleration, not increase it. Basic dynamics, bro.
well if for some reason you will spin your wheels while going 100mph the drag will make a downforce that will make traction thous eliminating wheel spin and making power. easy. never saw a wheel spin going 100mph though
+Dark Lightning Miller's all downforce attributed to air deflection anyways, which isn't that much unless its a fast course. Downforce due to gravity is still there.
This is a very over simplified explanation, but mostly accurate for the general purpose. If people rally want to know about the subject of aerodynamics and fluid flows, you have to take an actual class. Air has such a high reynolds number that it will never be laminar on this earth, although it can be less or more turbulent than a different section in an airflow. Nonetheless, the terminology is incorrect. Also, it's always a trade off. If a car has all the traction it needs without extra downforce, then you are effectively just making the car heavier at high speeds. And let's be real, at the speeds that normal cars (not race cars) struggle with traction, a spoiler/rear wing, will not help. Also, you have to take the conditions of the race into account. High speed turns, wings/spoilers can improve if designed properly. Drag strip, probably not so much beyond reduced drag if your aero kit can perform that way, but that has more to do with the car's overall coefficient of drag (which may or may not be helped with a spoiler) ;-)
First off, why would you choose a convertible to demonstrate aerodynamic principles on a car with spoilers/wings? The soft top creates turbulences so there is close to no laminar flow there to reach the spoiler/airfoil. Why didn't you take a standard 370Z coupe or even the beloved 911? Next up, you compare two almost identical street cars in a straight line race - the only difference being that one has a spoiler attached. It doesn't make any sense, that the one WITH the spoiler would win. It's called -spoiler- for a reason, it spoils the air flow and thus creates drag. The downforce/reduced lift is irrelevant because loss of traction a.k.a. wheelspin would only occur at the start, when the speed is at its lowest and where aerodynamics have the least impact on performance. It then makes _even less_ sense that the car equipped with an airfoil/wing would win that race, because that creates _even more_ drag. Also, when you drew the inverted airfoil for a car, your turbulences suddenly formed on the high pressure side. Finally when you put the cars in the wind tunnel, you should have let them sit on the ground instead of positioning them midair like a plane.
If you watched this and then watch another video about how DRS works, you'll be confused because both video would be contradicting each other But lemme solve that: trust the DRS, it's the correct concept and proven IRL...
Thanks for the video. Me and a friend bought a go kart and we are looking for better ways to making it go faster. While my friend knows everything about the engine and stuff, I'm the one that knows aerodynamics. We are either going to do drag racing or just regular old racing with it so we were going to put roof flaps and lower the side skirting in case it spins around so the air won't get underneath the car and blow it over. Also for mainly straightaway speed we're putting a spoiler, a splitter, flaring the ends of the side skirting and making the back end of the car stick more out to the right side and not the left side all purely for extra down force and side force giving us a lot more speed. We're also looking to putting a windshield and a metal or steel bar around the side of the car and tires protecting the car and more importantly the tires in case of an accident. And this video helped a lot for putting a spoiler on the car, it would be wonderful if you can post a video concerning the front splitter of the car if you haven't already, thanks in advance if you do.
this is a terrible video. cool wind tunnel but there's not enough space here to list everything you got wrong here. Wings and spoilers create down force which aids in handling but also create a lot of drag which slow you down. Some racers use wings and spoilers to help grip on cornering. But look at the cars that set land speed records and you won't see any drag inducing wings or spoilers slowing them down!
Excellent point; I believe it is because they design the body to produce that downward force and thus would not need the spoiler. The drawback is a very non-maneuverable vehicle that is excellent at straight-line speed but can't turn very well. Spoilers add that downforce while allowing the car to maintain a more-car-like (and less-rocket-like) shape and maneuverability.
+Matt Stacey that is exactly true. But I the video it states that everything else being equal the car with the spoiler or the wing would be faster which is simply not true. It would, handle better but it's acceleration and top speed would be slower.
Assuming the perfect conditions outside the car, the simple fact that it weighs more than air is enough to make it stay on the ground. I can't even think of any way a wing could increase top speed, like the video claims.
+Numiro You're missing the whole point of this video. The fact that once moving, the airflow creates pressures thus changing the vehicle weight is the subject.
WTF! this video could not be more wrong. Aerodynamics are all about tradeoffs, sure youll get downforce from a spoiler but you also get incredible drag. Why do you think F1 cars have drs. The average sports car doesnt have the power to break traction at high speed so when racing in a straight line a spoiler is complete and utterly useless and only adds DRAG!!!
+TheFlyingPineapple First: F1 Cars have wings. Second, a Spoiler increases the drag of car. The only task of a spoiler is the elimination of the lift the cars produces. Wings create downforce (in contrast to spoilers) but both of them create much drag.
+Really blub I know it's counter-intuitive, but spoiler do decrease drag. That's why you see almost vertical spoiler on the back of NASCARS. Here's a good little article explaining how they work: oppositelock.kinja.com/wings-spoilers-youre-probably-doing-it-wrong-1665312667
Increasing the angle of attack of the wing doesn't increase lift. Lift is upwards. Drag is backwards. When you increase the AoA, you are creating more force, but it's more drag than lift. Also, you don't want the air to separate and create turbulent flow. When separation occurs, that generally means there's a loss of lift and increase in drag. That's why planes stall. One last thing, the turbulent flow at 2:33 should be on the bottom, in the low pressure area, not the top, high pressure area.
Increasing the AOA does increase lift (Or in the case of a wing for a car, down force). Drag does increase but the increased AOA creates a larger difference in air pressure increasing lift. Also, spoilers/wings such as those of F1 cars don't behave like an aircraft wing when stalled. In fact, drag is reduced as the load is reduced on the wing due to lower upwash. I'm not saying the video is right but at least get your facts straight before critiquing someone else.
DynamicOyster Make the angle of attack 25 degrees. Now make it 89 degrees. Which one produces more downforce? I should have clarified. Increasing the angle of attack AFTER A CERTAIN POINT, does more harm than good. Technically, a wing is stalled when there is no airflow across it at all. Just figured I'd say that, because in that instance as well, drag and downforce are pretty much null. As for "stalling" F1 wings to reduce drag and downforce, (like F-ducts, flexing wings, etc.) I don't totally understand that that works. I'm not quite sure how, so if you'd like to explain, then feel free. The thing is, though, F1 cars are incredibly complex and work on principles not at all covered by this video. My best guess would go to secondary effects caused by the stalling, reducing drag that is otherwise there, so it's not the stalling itself reducing drag. You should also note: "generally".
There are many people better at explaining these things than I am such as SomersF1 and ScarbsF1. Serch them up on google along with the topic you are interested in.
No probs! Let me know what takes your interest as a general field (low speed, high speed, super/hypersonic, etc), I might be able to point you in the right direction. Little tip, if you're wondering what the effect of compressibility on lift and drag is, look up the Prandtl-Glauert singularity. It's relevant from .3 to about .7-.8, where the body enters the transonic regime. Have fun!
You're right, the turbulent airfoil should be in the low pressure area under the aerofoil spoiler on the aft. I think he just made a ''little'' mistake there. :)
Great video helps me learn about spoilers at first i thought it just push it down. Keep making videos like this! Hope you have a video on superchargers and turbochargers!
wait... but cars with spoiler will have lower top speed for more downforce (-> stability), in this case the one without any aero kit should be faster (in terms of top speed)?
In a straight line, less downforce is better. The wing or spoiler will help with downforce to keep your car on the ground but it makes the car heavier and will slow you down in a straight line. It will help in cornering though, so a car with a wing can run around a race track with plenty of sharp corners faster than the car with no wing.
@@troyandrade435 if i am driving daily on a super highway/ expressways where 100 kph min speedlimit is required where you will be driving for atleasr an hour straight. Is having a spoiler on car a good idea?
@@heymanbatman A spoiler or wing will not make much difference in everyday driving, but the difference will not be that important unless you are racing. If you add a spoiler or wing to a daily driver car, it is more for looks than performance.
spoilers dont do much in drag races because the wheels only lose traction at low speeds where the spoiler provides no downforce. In fact the spoilers and wings will also increase drag slowing the car down
"Lift" occurs relative to the airfoil, regardeless of which way up it is. E.g. the horizontal stabiliser, (tailplane) of a conventional aircraft is mounted to generate a downforce, like the spoiler on a car, but it's still creating lift. Any lift generation will result in drag. A spoiler that reduces lift should reduce drag. There's actually an academic debate at a much higher level than RU-vid about what really generates lift. It's been going on since at least the beginning of the 20th. century, if not before, involves mathematics, infinity, and a bitter rivalry between Cambridge University and Heidelberg. I don't think they've found a definitive answer yet.
Flow separation was on the wrong side, drag is generated at the forward stagnation point, called form or pressure drag, as well as all over the surface of the aerofoil, called skin friction. The former has to do with shape, while the latter - viscosity. Boundary layer separation is an effect exhibited by all objects traveling in a fluid, depending on a few factors, but with aerofoils - it's angle of attack. Basically, viscosity causes vorticity, which causes separation at high angles of attack.
Wow...just, no, on so many levels. A) A spoiler or wing or airfoil has absolutely no impact on a car at rest or upon starting (other than physical weight). B) Upon initial starting, the limitations on acceleration are weight and traction. With no air flowing over the spoiler/wing/airfoil, there's no improvement in traction but a negligible increase in weight. C) At speed, spoilers, wings, and airfoils ALL increase drag, reducing acceleration in a straight line. The ONLY exceptions are those which extend the rear of the car into the dirty air without protruding into the airflow. This is why cars with active aerodynamics typically have a max-speed mode which keeps the spoiler/airfoil from extending in order to minimize drag and resistance and maximize speed. D) Spoilers, wings, and airfoils are all designed to improve downforce to improve grip, which is a limiting factor (after startup) only when cornering. They are never desirable for straight-line performance. E) Airfoils increase drag significantly, because they are in the air flow and presented at an angle to the direction of travel. There can be a bit of Bernoulli effect, if properly designed and gapped away from the surface of the body, but it will never overcome the amount of drag gained by putting a solid object in front of the air. Drive down the road at speed and stick your hand at an airfoil-like angle to see how much drag is applied to your hand. This is why max-speed cars such as the Bugatti Veyron and its descendants can drive 270mph but more powerful & lighter-weight open wheel cars (such as Indy & F1 cars) top out at 230mph even on high-speed tracks like Indianapolis Motor Speedway, and 190-200mph or even less on courses with twists & turns. Seriously, a complete lack of understanding of aerodynamics here.
The Veyron Super Sport's world record runs were up to 267.8mph...close enough to 270mph for this discussion. Its descendant, the Chiron, is widely recognized that it will be able to top 270mph and some even speculate up to 280mph. Therefore, my point stands there. You are correct, though, Indy & F1 cars are not more powerful...I misspoke (they are faster 0-60 than the more powerful Veyron, but that's due to a huge weight advantage). However, the major point (rather than the minutiae) is that air foils do not lower drag and increase the top speed, which is what is contrary to what is claimed by the video. That is easily evidenced by the fact that Veyron's standard top speed is 213mph due to the aerodynamic aids that deploy at 140mph; the only way it's able to overcome this drag is by going into high-speed mode before even starting to drive, which disables those air foils from deploying.
1. In a straight line, a car WITHOUT spoiler will actually be faster, this is why the Bugatti Veyron's wing RETRACTS in top speed mode. 2. You drew the turbulence on the TOP of the wing in the upside down wing example at 2:40, it should actually be on the bottom.
+hectorae86 GJ FUCKING job its complete opposite with the bugatti, in top speed the spoiler comes up. Before you re-massage me about you think im wrong, just look it up. have a good day
1344mads Ouch, does it hurt my friend? I mean, lack of brain cells must have some side-effect right? I said the spoiler retracts in top speed MODE, which it FUCKING DOES. I "normal" MODE the wing will indeed go up above a certain speed. And just top help you out with your brain problem, the Bugatti Veyron has a special key that you have to insert into a slot and turn to put the car in top speed MODE, only in this MODE does the Bugatti become capable of reaching it top speed, hence top speed MODE. Let me know if you need more help understanding basic information.
Dude i have one question why should it RETRACT in top speed ? a spoiler give more grip (because of the downforce). when a bugatti are in max speed or MODE it also get more lift, thats why you need the spoiler to counter that lift, so it can keep the speed and control. And if you insist, give me a link or proof where it say THE SPOILER RETRACTS IN TOP SPEED/MODE.
+1344mads it RETRACS in top speed mode because in such speed the generated downforce from the wing is so big that the rear suspension system would collapse from the total weight (actual weight + weight generated from downforce) you can look that up as well ;)
@@davidmertes6308 It is a spoiler, it's meant to create downforce. It increases drag and increases friction. Therefore, the car would definitely be faster without it
@@ilan9588 A spoiler is not automaticly there to create downforce. In most production cars when there is a spoiler its to guide the airflow at the rear to minimise turbulent air flow. By doing so it reduces primarily drag and you typically reduce lift. To yourself a favor and educate yourself before playing teacher in the internet.
@@davidmertes6308 After apparently not being "educated" about the subject, I went on the internet to see if anyone shares your opinion. I haven't found a single instance where a wing doesn't add weight and create more friction and drag. All a wing does is increase friction by reducing lift and therefore decreasing the top speed. It is a fact that friction (and drag, as well as added weight from the wing) has a negative impact on a car's top speed. And that's that. Oh and keep in mind, we're talking about REAR spoilers here.
@@ilan9588 Your fault is that friction and drag are not the same thing. Yes you create friction on the wing surface but you can still decrease the overall drag. At cars the major cause of drag is turbulence air behind the car. Especiali with sedans or coupes you have turbulent air over the rear window. Since turbulent air flows faster than the surounding air the dynamic pressure drops and it generates lift and drag at the same time. When you ad no a Spoiler you can redirect the airflow and reduce this turbulences greatly resulting in less drag AND Lift. You can see this on several cars like the early and midrange Imprezas and Lancers. For sure when you tune a car and make the angle stifer and adding a reverse Wing shape you trade drag for real downforce but thats not often the case in normal production cars since they need to hold a certain fuel economie. Today you find also spoilers in almost every car in some form to reduce drag. Oh and since i studied Automotive Engineering for 5 years and sind 2,5 years i work in Aviation as an Engineer i thing i know a little bit in this topic.
Wrong. The spoiler increases the size of the turbulent area, but it also creates thrust that in many cases may result in a lower overall drag. Mean while the wing will always increase drag and have a turbulent area behind it. Also, improving high speed grip will not do some much for you in a straight line drag race, but reducing drag will
So the bigger the spoiler the higher the top speed? 100 percent wrong. Look at the high speed salt flat cars. You don't see them with big spoilers. You see them with with spoilers fitted on them to make there cars longer. Look at NASCAR's. Low speed tracks you see them with higher pressure spoilers and wider fronts for more down force. Then on the High speed track you see them with more narrow longer fronts with a shorter spoiler. Nhra drag funny cars for example are long but with a big spoiler. Why for the big spoiler? Be cause for traction for acceleration. Butt of the track was longer and not for acceleration, it wouldn't use a high HP motor and not such if a bug spoiler. Factory cars like a Nissan 350z for example in a drag racing sense. The spoiler will cut mph because of its pressure to push the car down. To get very better traction. Get better wider tires and tweak the suspension. It depends on the weight and HP too.
Justin Walters He's correct though, the downforce which allows for more grip in corners and thus higher cornering speeds can be reached. Nothing comes without a cost though, the cost here is increased aerodynamic drag due to the spoiler. You can adjust some of them to increase or decrease downforce and likewise drag. In a straight line race for a "normal" car a spoiler will only slow down it's top speed and acceleration above a given speed such as lets say 130mph. In low speed situations a "normal" spoiler is fairly useless, unless you install a huge spoiler set to an aggressive angle.
This is not true. It's just to get significant down force at a lower speed a larger spoiler is needed and must be set to a more aggressive angle. Perfect example of this would be in tight circuit courses where the cars never get going "fast". Which is a subjective term but you should be able to figure out what i'm trying to convey.
And that's why automatic adjusting wings are a thing. Because just sitting there it will slow your car down until you reach a certain speed where the downforce actually helps the tire grip. The speed is 100mph by the way.
Cars with no spoiler will win in a straight line but lose in the corners. The spoiler will not even make serious downforce till around 150km/h+. I have tested this on track with GPS datalogs. The Diablo has a lot of drag despite its supposed aerodynamic looking shape. Wings are for corners, not for straight line speed.
High engine horsepower is no good without the spoiler, because the spoiler is actually an inverted wing, which creates down-force. It also increases handling and acceleration by 45-55%.
Arthur Rattew Please do a bit more research before you make such an assumption. The F1 cars today have DRS which effectively reduces the car's downforce in a straight line to increase speed. Unless your car is a top fuel dragster with 3000hp, the added downforce of a wing will only slow your car down in a straight line.
sodazman "Please do a bit more research before you make such an assumption" I am sorry, but you are *completely* and *utterly* wrong in your assertions. I would *strongly* recommend you take your own advice and do some proper research. Even a small spoiler (I am assuming we are talking about rear spoilers, and not front spoilers for these elaborations) can produce a notable decrease in drag, while increasing down force at the same time. They can (and commonly do) do this by altering how the air leaves the rear of the vehicle, resulting in less turbulence. You previously asked for evidence to support people arguing with you on this ("Why don't you show some evidence instead of making a general statement?") I would be *glad* to provide. These results are quite common, and repeatedly so- Please dont take *my* word for it- I wont even bother citing textual information supporting myself (which is quiet easy to do, 30 seconds on google will demonstrate this concept)- I will do one better, and i will cite an actual, measured example. forums.hybridz.org/topic/55944-windtunnel-test-data/ This is a community of automotive enthusiasts centered around Z cars (Primarily 240/60/80zs, but later gens as well) who collected money from the community- and used it to rent a wind tunnel. They then conducted numerous tests with their cars, testing popular modifications done to these cars (to see note only if they worked, but to what degree if any), and popular ideas/theories. Of relevance to this discussion, please refer to test 9, and test 11 (Test 10 is on topic as well, but in my opinion the difference between 9 and 11 is more on topic with the matter at hand due to the types of spoilers in use between these tests). Please note the *only* difference between test 11, and test 9- Is the inclusion of a small, cute, and cuddly- Spoiler. Only a few inches tall. Now please note the differences measured (multiple times, each test was run 3+ times). Of no surprise, the spoiler reduced overall lift, by about 100 pounds (mostly measured at the rear, again of no surprise), but not lets look at the drag. The coefficient of drag measured on test 9 was .48- What happened when we added this little spoiler? It changed. It went *down*. *Down* to .453. You. Are. *Wrong*. Spoilers can, and do commonly reduce drag as well *depending* upon the application.
It's much easier to think of this in terms of resultant vectors and basic trig. If you have an air foil tilted up, you have a force in the reverse direction and a force in the downward direction, the wing is sort of the resultant vector of that triangle. So I think of the problem backwards, given the resultant vector, determine the down force and drag.
The upload is correct. by reducing lift drag friction decreases and therefore top speed, acceleration, and mpg is improved . of course if too much down force is created acceleration top speed and mpg can also be negatively effected but generally that is not the purpose of spoilers on passenger cars.
This video really makes MIT look bad. It really needs to be redone. Clearly done by people with theoretical wet dreams about physics. Typical of informative videos done by non-experts though.
A lot is going on below, so I wanted to try to add a few information about the stuff we are talking about without adding more confusion. 1. Downforce grows when you go faster and faster, at some curves F1 cars can not make the turn properly with 180 km/h but they can with 250 km/h. 2. Coefficient of drag is around 0.7's at F1 cars but it's around 0.24's at Tesla Model S. So, as you can understand from that info alone, trade off between downforce and drag makes you faster if you calculate precisely. Drag can be a friend rather than a foe depending on what you have in your arsenal. 3. There is no downforce in the begining for all three cars and there is an added weight for the cars which has spoiler and wing compared to the one without those. That means, in theory, the one with no wing or spoiler would make a slightly better start, and keep that until downforce starts to kick in. At some point -when they reach to enough speed- trade off between drag and downforce would start to pay off and while cars with spoiler and wing would keep on going with a pace, one without them would start to have issues because of the lift.
Great video, easy to understand and clear explanations. Everything you say is relevant and you don't jump topics like some videos I've watched recently. Thanks!
It will if you have a powerful engine and RWD. Compared to an identical car without a spoiler, it will regain grip sooner and it will accelerate sooner and faster. However at very high speeds the spoiler will create too much drag and will slow down acceleration and the spoiler-less car will catch up... so... on a short drag 1/4 mile a "spoiled" will win, while on a 1-2 mile drag the car without a spoiler will catch up and win. But after all it depends on vehicle aerodynamics and engine power.
Noo.. On a short race, the spoiler will have no effect on the car since the air moving through the wings are minimal. But at over 200km/h, clearly the wings will create drag and slow down the car.
Top Fuel dragstars need a spoiler so they don't fly into the air or crash; which you see a lot of them on youtube. At those speeds that the dragstars are travelling in, they clearly need spoilers to stabilize the car.
A wing in the turbulent bubble behind the carrera would only increase drag, but don't expect any lift. The objective of a spoiler is to ensure that the flow separates at that point, instead of having the separation point oscillating back and forth. The spoiler decreases drag by tripping (spoiling) the flow at a well-chosen location. An F1 car has the aft wing above the wake.
Glad you said that, i was thinking the same. When air is being compressed, it is at a higher pressure (more air in same volume = increased pressure). Air that is allowed to expand is lower pressure... i was confused as to why it was being explained the opposite way.
10 лет назад
Thats great! Which type of nozzle did you use? Can you better describe it, please? Thank you
First, if the tires of a car cannot maintain optimal grip, then a spoiler is needed to push down (add weight to the car) the tires so it can have more contact with the asphalt. For a car to accelerate faster, it is needed more power, less weight and lower air resistance. So, spoilers are for maintaining grip when steering with high speed. ...and sometimes prevent some special cars to not take off the ground.
ah interesting, didn't realise it was such a high speed needed for compression!! Thanks for the leads, i'll read up on Bernoulli's principle and the boundary layer phenomenon. Thanks!
Downforce of any type from a car will almost always cause more drag and slow you down in a straight line. The drag a spoiler makes is a trade off for downforce which translates into more grip in the corners allowing for faster cornering speeds and quicker lap times.
Very nicely explained! I`m looking for a wind tunnel like the one in your video. Maybe you know, where i could buy something? I do not want to make it by myself, have too much to do with my RC Cars..lol Best regards Martin
Very interesting! Your thoughts on my question! My 350z( look up bull run prep 350z) it handles great on the track but I think with a rear wing , right adjustment, not too large it will perform even better! Your thoughts! No under or over steer! Excellent acceleration, corners are perfect! There are 2 track day videos posted as well! Thank you!
100% right your explanation. However the reason for the wing is to keep more speed in corners. By sacrificing a little of top end speed and be faster around corners, the car goes faster overall around the track. My 2 cent!
Very well explained but I have a question re the wind tunnel simulation. In an actual driving vehicle there is no airflow over the road whereas there is in the wind tunnel. So, are the pressures accurately reflected in the wind tunnel?
i do know that spoilers were added to cars soo that the rear wheel drive cars could have the rear forced downward and would have more traction and grip for the car to drive forward. but sometimes it could lead to a little drag, and when trying to reach to the top speed, the car is very very sensitive to little bumps and pebbles, tiny air drags and sometimes weight. any of those could make a great impact on the car when it is on its sensitive moments of top speed. i learned it from nascar racing when they put those little fan spoilers in the back of the cars in the 80s 90s and very early 2000s. the fan spoilers were placed on the car and it improved the cars traction and a little bit on speed but it kinda made a little drag for the car. then they tried the wing in 2009 which was a success. but in safety issues when the car spun out of control and skidded backwards at high speeds, the cars were prone to lift up like a plane and flip over and onto its roof upside down. soo they kinda went back into fan spoilers but in a more airodynamic way. this video is kinda right. i wish i could explain air flow in a more simpler way through text but its hard to explain. i ride bicycles for 7 miles a day and i watched very very closely by what i put on my bicycle. it can be a light, a flag , a basket on front and back , a fender and knobby tires . i do know that it may affect my bicycles riding performance with each of those items above on. it can be weight and wind drag. no ,i dont put wings on my bicycles nor spoilers. but if you are a cycler like me who travels 18 mph and 7 miles from there to back every day, you may notice that any accessories you put on may affect your riding performance whether big or small. same with the car.
The thing is, at a smaller scale physics work differently; the air is thicker relative to the scale car, that's why companies do a full size cR earodynamics, same thing with pressure
I have a question , I seen this driver of an STI have a stock spoiler . This is the newer like 2015+ . They put on a rear roof spoiler that is kinda big and flings upward . Wouldn’t that stop or slow down the function of the stock spoiler . The air is being redirected upward instead of from the roof straight down into to spoiler . They whr getting props but was it for bs from ppl who do t know or am I just not knowing what I’m talking about . The rear roof spoiler was being turned upwards . 🤔
