LS1>girlfriend

iTrader: (19)

at 180+ mph...

NSSANE02

iTrader: (14)

Ehh... a stock base vette can do over 180, hell I've seen a bunch of modded fbodys that can do that. Granted those cars can't do it around the track like a nascar but a higher end Ferrari could, I bet an Enzo could eat a nascar but thats not my point really. Look at the Formula 1 cars, they are capable of way over 200 and they could litterally drive circles around a nascar on any track but they run on complicated/interesting tracks not circles (most of the time). To the OP I'm sure the 4th gens make some amount of downforce but they are still not very stable at 140+ with stock suspension and ride height, at least mine isnt.

landonew

He did not ask if it was a benificial amount of downforce, only whether or not downforce was present.

The answer is YES!!! In fact, just about every object not made to fly will exhibit some dort of downforce when moving through a fluid (fluid is a technical term for matter that conforms to its contrainer such as gases and liquides). It is a result of bernoulli's principal (the same principal that explains flight), air(or any gas) moving at a higher comparative velocity will have a lower atmospheric pressure.

Jeremiah

iTrader: (5)

The Mecham TA was designed with a couple of these things in mind.

The extractor hood helps draw more air through the radiator helping to reduce the extreme engine temps generated at high loads/speeds by eliminating the pressurized pocket under the hood. At higher speeds there is also a low pressure erea above the four ports, this low pressure erea further helps to extract the hot air, this is how the hood recieved its name. While relieving the under hood pressure you also lessen the chance of the front nose trying to lift at high speeds. A scaled down less extreme example simmilar to the C5R Vette hood and the new Vipers. Some cars also use fender vents ect. that serve the same function.


Due to the air plane wing shape the fourth gens do have the tendancy to want to lift in the rear at high speeds like mentioned before, the high down force rear wing corrected this and greatly improves the stability at high speeds. The Mecham TA also has a lowered ride hight and a very pronounced rake further reducing the amount of drag as well as further reducing front lift and again greatly improving the stability at high speeds.

With a successful venture in SCCA racing they gained a good amount of knowledge that was later applied to the Mecham TA. The Mechams were designed with more than appearance in mind, the earodynamics were very effective.

Shooter_Jay

pics/stats of your car?

infinitebird

iTrader: (11)

Not exactly. Lift is created because air travels faster over the top of the wing than the bottom, this creates a pressure difference on the wing which leads to a greater pressure on the bottom of the wing than the top of it, creating a net force in the positive vertical direction. It isn't the distance air travels, it's the difference in velocity that creates the pressure difference.

Shooter_Jay

it's the distance that forces the higher velocity, I think what I said was correct.

Jeremiah

iTrader: (5)

Its pretty much as delivered from Mecham with exeption of the power plant/drive train. It now has a 422 stroker that as of last Sunday made 560/507 Rwhp/Tq NA on a Dyno jet.

There poor quality pics but here you go..

Jeremiah

iTrader: (5)

I think your both correct..

It has to travel faster because the top side of the wing has more surface erea or distance for the air to travel than the bottom side. This is what creates the difference in air speed/velocity.

Shooter_Jay

Thanks.

And that mecham is pretty cool looking. I don't think I've seen that before, and I've been on here a long time. Sounds like it's fast too.

JD_AMG

You can thank GM for that when they put the shitty decarbon shocks on our cars... Invest in some Konis and you will stick like glue.

Shooter_Jay

I'm no aerodynamicist, but I am a thinker, and I thought, at least close to the ground, the effect would be opposite. I think the effect does not work as you say, assuming no downforce wings, velocity lifts cars off of the ground, not pushing them down towards the ground.

gallardo259

If u want to know about downforce, study an F1 car. All those little winglets aren't for good looks. An F1 car generates 1g of deceleration from simply letting off the gas pedal at 150mph because of all drag the downforce pieces make. I know that the tires they run have a part in their grip levels, but they can pull over 4g thru Suzuka's 180R with the help of those aero pieces. So does an f-body create downforce? well yes, some, but not much compared with race cars or more exotic performance cars.

theycallmealex89

when is the last time you went 180. whens the last time you went 180 and made ANY turn? i wouldnt try it, but you let me know how that goes, if you can control your car with all the sweat on your palms. and yes f1 cars are sweet and turn. but thats not even remotely close to a real car. if someone wanted, they could take a nascar car and put the interior back in.

edit: and seat 5.

LrngCrv

If you are a thinker than think about the fact that the bottom of your car is not super smooth like the bottom of an airplane wing. Then realize that the ground is also in the way to prevent lots of air from quickly passing underneath the car. A lowered car would have even less chance of lifting but even a stock ride height car won't be flying away anytime soon.

The main thing isn't that you are feeling lift on the car, it is that it takes more and more downforce on the car the faster it is going to keep it stable at those speeds. Less weight pushing down from moving forward means you need more aero-downforce to make up for it.

Production cars generally are designed for fuel efficiency and low drag, downforce is almost always lacking on them, especially newer cars. Downforce creates drag, I'm happy not having a lot of downforce on my car.

Shooter_Jay

I think I mentioned that in an earlier post.

Shooter_Jay

As I remember from the hotrodding history books, in old school racing of a sort, at top speeds the cars were lifting the rears and crashing until carrol shelby I think it was shaped the tail of his car to create less lift by putting a "fast-back" style tail. But who am I really gonna believe, you, or carrol shelby

infinitebird

iTrader: (11)

Sorry but no, that's not really accurate.

The main cause of the velocity difference is air deflection, not simply the distance travelled over the wing.

If your explanation was correct angle of attack would be irrelevant to lift, whereas if you look at aerodynamic data, its clear this is a vital component and is what generates most of the lift.

On the top surface of the wing, air easily slips over it and is not met with hardly any resistance, so it travels very quickly over the top, whereas on the bottom at any nontrivial angle of attack the air is hit hard by the shape of the wing and slowed down significantly on the underside. This is what causes it to travel slower across the bottom.

It's pretty easy to think about in simple terms. Put your hand out of a car window parallel to the ground. You don't feel much. Then curve it up slightly giving a small angle of attack. You only feel the air hitting the bottom of your hand, not the top. As you increase the angle of attack, you feel a greater force on your hand. Similarly, increasing the angle of attack of a wing (up to a certain point) generates more lift.

infinitebird

iTrader: (11)

You seem to have the common misconception that air which is divided at the leading edge has to meet again at the trailing edge. This is not what happens.

btw, I'm not claiming to be an expert here, but I did do part of a minor in aerospace engineering, so I have a fairly good understanding of the process I think.

Shooter_Jay

incomplete maybe but inaccurate, I don't think so.


thus the partial college course proof...