I am still trying to guess if you're a rocket scientist, a high-school dropout or just a pompous ass. Since you obviously had nothing to contribute, why say anything? Have you disproven anything I've written? Not likely. On the other hand, there have been a few other posts that validate what I tried to explain. Go troll off-topic...

i have a quiestion, does the cut away of the EVO VIII spoiler reflect that of an aircraft wing?.... if it in anyway doesn't then your theory doesn't hold water... the only reason aircraft wings function as they do is due to their design... Not trying to prove anyone right or wrong just trying to throw out questions that might contradict things

It was merely to point out the way air flows - an aircraft wing is much more complex than our spoiler, as was pointed out. My point there was that we have two areas of pressure vs. one with an aircraft wing. I'm done trying to help out...

Ah, yes...the square law... {thumbup}

In the recent Rally of Jamaica, a driver lost his rear wing (Evo 5)and replaced it with one from his road car... he had to as the back end was VERY NERVOUS, after fixing it... we went on to win 5 stages.

http://www.rallyjamaica.com/Pics_day...s/P1010014.jpg

On the road... well I guess its mostly for style as you should not be driving that fast ;) ;) :D hehehe

Chris,
When can you have it ready... ;)

Thanks for your contribution. Dont get discouraged.

Sean

^
Chris: I agree. Most people that understand what your talking about don't post ;) Good info man, it is appreciated.

Actually, I am a mechanical engineer with a pretty large background in aeronautics.

Speaking of pulling things out of thy rectum - maybe you should heed your own warning.

What these guys are talking about isn't coming out of their asses. It IS physics.

Go troll somewhere else.

The overall car likely produces lift, much like a Porsche 911 does. However, to say the wing is not producing downforce but only zero lift is wrong. Probably not as bad as calling it a spoiler though, spoilers only flow air above them for downforce. If you are producing zero lift, the wing is doing nothing for stability and only creating drag. The wing on the evo has a downward angle of attack aprox. 3-5 degrees. Additionally, the top is flat and the bottom is curved so it is a cambered wing which even at a 0 angle of attack, would produce downforce.

To say that surface (rear trunk) would be influenced some by the wing is correct. That is the very reason that given the chance, a race car designer will mount the wing behind all body work. Since the underside of a wing is a low pressure area, the air pressure on the trunk on an EVO (under the wing) with the wing would likely be lower than the pressure on the trunk of a wingless evo. However, the loss of downforce (or lift) on the trunk is not as large as the increase in downforce that the wing gives. That is why racing cars still have wings, even when they must mount them over bodywork. Also, the higher the wing is mounted, the less it will affect the air flowing over the trunk, and the more efficient it becomes.

While downforce has no mass, it is a force and weight is a force as well. The beauty of downforce is that it pushes down on the car (like a weight) but it does not have to be accelerated and stopped. For purposes of calculations, downforce which is due to pressure acting over an area, can always be converted to a resultant force acting at a specific location. Because the wing is mounted behind the rear tire, it can reduce the load on the front tires in the same way that a see saw works.

The car doesnt break appart because the load is distributed over the entire car. Would you rather have a hundred pound blanket placed over you, or a knife pushing with 20 lbs force? How the load is disributed makes a huge difference. Finally, if someone is producing fences to direct air away from the underside of the rear wing, then they are hurting the wings effectiveness, not helping it.

I think the last two posts vindicate my point, even if there are slight disagreements. Thanks for the assist!

the wing is inverted which means the low pressure area would be above the trunk(which means nothing). the incidence of the wing is great enough that were it right side up the rear end of the car would get lighter, when driven at speed. as installed it pushes down

the fact that it is an airfoil simply means the designer was trying to reduce drag. you tuner nuts might try shaping the trailing edge knife edge sharp. litigation and manufacture prolly why it is blunt.

the turbulence of the roofline negates a lot of downward pressure, that is why it is as large as it is and as high as it is, to find clean air. nevertheless it will push down on the back of the car.
the underside of the car might benefit from a smooth skin, drag wise, but it would be suited best with as little air under it as possible.
that is why race cars have very low body moldings- to keep the air out.
just an opinion, bruce

Speaking of which -- it seems to me that you could get a lot more efficiency from the wing at a lot lower speed, if the wing incorporated a leading edge slat and a trailing edge flap, just like a regular aircraft wing. I guess it would add some cost and perhaps that's why it isn't done.

This is the only post in this entire thread that has any resemblance of correct information.

And regarding F1 cars, just as one example, the rear wing is mounted to the f*****g gearbox, not a trunk or some other peice of thin metal.

Well how about summarizing the principals and forces at work here then. I would sure like to benefit from your knowledge.

Speedlimit...

sorry, the low pressure above the trunk does nothing, it is the wings force through the mounting points that is pushing down.
tape a piece of paper to the rear window at it's base, so that it covers the trunk (or use pieces of yarn). go for a drive that piece of paper is going to float up. there is just to much "bad" air behind the roofline.

havn't you guys seen models laying accross car hoods or trunks before, they have to weigh at least 90 lbs each.

almost any car body will make lift at speed, heck a pimple on a nats back will make lift if he is going fast enough.
the wing is there to counteract the lift. it prolly also helps to cut the airstream some, same as a spoiler. but, just guessing again, I wouldn't think that is a big factor.