OT: Fuel mileage and wings
 

Entertain me on a rainy race weekend...So a 25 square foot top wing on a sprint car drives the car down and makes it stick. In these days of $4/gal. gasoline, my mind has been wandering to unorthodox methods of getting better fuel mileage. Here's my latest thought (please offer yours): What would happen if you were to take a 25 square foot top wing and turn it upside down and mount it on your street car? At low speeds, I would imagine not much would happen except for strange looks from town folks. But, at highway speeds what would be the effect? Would it actually take weight off of the suspension, thereby requiring less energy to propell it (fuel)? ***maybe I should stop here and say, please don't try this (yet).**** If this theory has any merit, there would certainly be things to consider, like would it fly:3:? Would it affect steering or braking? Would it do anything at all? Hey if nothing else, it's a great rainy race weekend mind execise. By the way, you heard it here first in case this is a billion dollar idea:32:.-----I can invision GM, Ford, or Chrysler, designing wings that adjust themselves as you go down the road for optimum up force/stability/fuel mileage. Whaddaya think?

Re: OT: Fuel mileage and wings
 

I think wings suck, dont matter if there on airplanes, racecars or especially on street cars.

Re: OT: Fuel mileage and wings
 

Well from racing experience, when we put the wing on the car we get about 2 laps per gallon. When we run non-wing, we get about 3 laps per gallon. The more frontal area you have in the air, the more work the engine has to do and worse fuel mileage you will get. This is one of the reasons semi-trucks get such poor mileage. I know what you're thinking, well, flatten out the wing. Well, wings also present a certain about of drag since they are hanging out there in the wing, so a lot of fine tuning/research would have to go in to get the 'perfect' wing-form for each model of car. But if it's not required, then the money won't be used. What would really help street-car fuel mileage is: full underbody trays to cover all those areas air can get sucked up into the body, delete the door rear-view mirrors and replace them with rear-facing cameras, no radio antennaes, actually nothing outside of the body since that disrupts the air-flow around the car, and induces drag. If you look closely at some new street-cars, you will notice some of these changes. The wheel-wells are getting closer and closer to the tires to reduce air from getting trapped in there. Wind-shield wipers are going under the hood-cowel to get them out of wind as well. I am aware of some Jeeps having under-body trays now too. And some passenger cars are getting lower to the ground to reduce the air flow under the car, reducing drag as well. The car companies are working on these things. The problem is, major changes are just too expensive to be made all at one time, so they incorporate them a little here and a little there.
Thanks,
Chad

Re: OT: Fuel mileage and wings
 

I've not looked for it lately, so I don't even know if it's still there, but I used to go to a program called "foilsim" (I googled it) and it had a program where you could adjust an airfoil (shape, camber, attack angle, etc.) and it would calculate lift, drag etc. I used it to calculate downforce when we ran with wings (you have to use a negative camber and negative attack angle in the calculation because this is made for airplanes). Anyway, you might take a look and see if this gets you started.

Tim Simmons

Re: OT: Fuel mileage and wings
 

So at 70 mph you now have no weight on the tires. This would mean you could not stop or steer the car. No tire grip. Think about why did nascar but roof flaps on the cars? Small, single engine airplanes take off around 100mph. A side note the D.O.T. has rules about wheel opening on cars. Why? So you can put snow chains on them. Just more needed rules from washington.

Re: OT: Fuel mileage and wings
 

don't think it would work. wings create drag no matter how you tilt them. it would reduce sprung weight but would not affect the mass of the vehicle. going up hills, the engine would still have to pull the car. the wing would reduce mileage. My suggestion, get a lighter car with a smaller engine and try to bring someone else on race trips to split costs and put more people in the stands.

Re: OT: Fuel mileage and wings
 

Drag is certainly going to counter any "lift" you would get by attempting this. Interesting thought though....

Hi Chad!!! :)

Dimpling the cars body to make air pockets will help drag behind the car. That is why golf balls have them.
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Re: OT: Fuel mileage and wings
 

so hail damaged cars get better gas mileage?

Re: OT: Fuel mileage and wings
 

Actually, it depends on where the dimples are at. They need to be placed prior to the boundary layer seperation point. A golfball has them all over since a golf ball spins, and you don't know which part will be the point of attack when. The dimples cause the boundary layer to stay attached longer, thus reducing drag. Did you ever see the 'slice proof' golf ball? They filled in a certain portion of the dimples on the ball, the remaining dimples would cause the ball to right itself during flight, and go straight. Anyway, anything out away from the car body will help cause boundary seperation and induce drag which of course is bad for fuel mileage.

Re: OT: Fuel mileage and wings
 

I will take 3 dozen of those golf balls! lol

Re: OT: Fuel mileage and wings
 

LOL.....well, I think the PGA officially outlawed them years ago. However, I believe you can make them yourself if you really wanted to. I'm sure you can find directions somewhere on the internet. :)

Re: OT: Fuel mileage and wings
 

There was a problem back in the 50's with a certain chrysler model with curved tail fins. At high speeds the rear end would lift.

Many cars have spoilers, Some are for show but the low slung ones are purely to break up the air sucking the car backward (Drag) Therefore improving Milage

Re: OT: Fuel mileage and wings
 

not true.. Myth busters did a show on this.. they used clay on the whole car, and dimpled the whole car.. both before the clay and after the clay and then after the dimples on the car.. The car with the clay and dimples actually got better gas mileage than the regular car minus all the weight from clay.. so if it is dimpled all over, you will get better gas mileage plain and simple.. so bring the hail, now im not sure how deep the dimples have to be before you start gaining anything.. it was a good amount they gained if memory serves right..

Re: OT: Fuel mileage and wings
 

I guess I should clarify. What I was trying to say is that you really don't need them over the entire car. Yes, MB did show an improvement with dimples over the entire car, but dimpling at certain spots on the car probably would have gotten the same result. Here's an excellent Air Force paper on some dimple research: http://stinet.dtic.mil/cgi-bin/GetTR...c=GetTRDoc.pdf

Part of the background research for this particular paper cited previous dimple testing:
"James Lake [6] examined dimple location along with comparing dimples to v-grooves and trip wires in his investigation on reducing sparation on a Pak-B turbine blades. He found that dimple location had an effect on dimple effectiveness. Dimples were most effective when placed slightly upstream of the unmodifed blade separation point. As the dimple was moved further upstream of the separation point, its effectiveness decreased. His research shows that for maximum effect, dimples should be placed as closely as possible to the point of separation."

That's what I was trying to say originally. Although hail-damage could aid in fuel mileage, properly placed dimples would be most advantageous. Now, the paper I posted goes further, looking at the diameter/depth ratio of the dimples, and how that affects the flow characteristics.

Re: OT: Fuel mileage and wings
 

Interesting topic. I love "talking airflow". We "dimpled" a couple of different Brigg's cylinder head's in the combustion area in different "pattern's/area's when we were racing kart's and we def. saw improvement's in "burn" and had to actually richin up the engine. It must have improved "swirl" as the engine sure "came off the corner" better / had better throttle response.