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Quote from richy :clearly a thicko who is putting you to the test on the basics. your career is obviously going as well as mine.

Your not really testing me per se, but you are seemingly unable to grasp the concept despite numerous attempts, not just by me, to correct you.

Quote :So this thread is about the amount of people who use the term downforce instead of lift on cars. so many people make this mistake of using the wrong term to describe the same force (by your own admissions). so we have found the cause of mine and others confusion. really people need to be talking about limiting the lift of their vehicle at speeds and having a vehicle that has low lift spoilers and wings. Not with downforce of course but with less lift, because if they had downforce that would be the wrong thing to say, because no road cars have downforce or anything to do with downforces. Its only lift with road cars and limiting how much lift it produces, with some other force that isnt downforce but it does the same thing? yeah I see where your getting at. Not.

The confusion is that a lot of people think that, because Mr Hamilton et al have downforce on their cars, and Messrs Ferrari et al quote downforce figures on their road cars (but for the purposes of this discussion I am using the term road car to refer to Clios, Civics etc, not high performance 'supercars' or 'hypercars' which more and more frequently DO have downforce figures quoted [at the very least]), they think their car must have some sort of downforce, especially if they add silly bumpers/wings/spoilers/skirts/aerials [delete as applicable].

The reality, as you now know, is that road cars generally suffer from an upforce (commonly known as lift, uncommonly known as negative downforce by weirdos trying to make a simple thing into an argument), that tends to reduce grip with velocity, even more than the tyres alone will manage. This upforce (lift) can be reduced (and in exceptional cases probably reversed (where it is referred to as downforce, and not anti-lift or negative repulsion)) by the addition of wings/spoilers/etc but usually only minimally; not enough to change the vehicle's capabilities or the drivers feel.

To suggest that the misconception is people using the term downforce to mean upforce is, frankly, ludicrous and not at all accurate (in the vast number of people I've come into contact with with reference to cars). It's like people using the term coffee to refer to tea, or cars to refer to hot-cross-buns.
Quote from richy :blarg

Tristan tries to explain to you (for the umphteenth time) that there is an error in your usage of the term downforce... Yes, downforce is the opposing force to lift, just like friction/drag is the opposing force to propulsion... BUT, if we take the TT for example, adding the spoiler to the rear wasn't adding downforce, the spoiler just optimized the airflow so that less lift occured... There is a big difference between less lift and downforce...

People nowadays don't comprehend that not having one thing doesn't mean the opposite...
You can't use the term friction anymore. It's anti-sliding force. And you can't use drag - it's called inverted positive... oh I give up. It's too hard to think of stuff to take the mickey out of richy. I've done the obvious ones, and if he doesn't get it now then there's no hope.

To everyone else: Never use a setup from richy - it will either result in a singluarity (too much downforce) or far-earth orbits.
Quote from bbman :Tristan tries to explain to you (for the umphteenth time) that there is an error in your usage of the term downforce... Yes, downforce is the opposing force to lift, just like friction/drag is the opposing force to propulsion... BUT, if we take the TT for example, adding the spoiler to the rear wasn't adding downforce, the spoiler just optimized the airflow so that less lift occured... There is a big difference between less lift and downforce...

People nowadays don't comprehend that not having one thing doesn't mean the opposite...

Can't it be said that the wing does generate downforce, but not enough to reverse the lift generated by the car? (thus giving the car less lift, but no downforce)

Or am I simply confusing myself now? ;p
Quote from Jertje :Can't it be said that the wing does generate downforce, but not enough to reverse the lift generated by the car? (thus giving the car less lift, but no downforce)

Or am I simply confusing myself now? ;p

I think you can, if a wing in isolation generates a downward pressure (or downforce) at 100mph, then attach it to a car and it can still generate that force, even if the car it is attached to is still generating (now reduced) lift overall.
This is why I find it hard to understand that no cars on the road generate downforce. Surely that designing and spoilers and smooth airflow counts for something. I dont see it adding to the lift so if it removes lift, thats as good as downforce?

edit: or is removing lift classed as "adding stability"?
Quote from Jertje :Can't it be said that the wing does generate downforce, but not enough to reverse the lift generated by the car? (thus giving the car less lift, but no downforce)

Or am I simply confusing myself now? ;p

I think that they will just tell you that its net lift overall, so there is no downforce from that wing. no downforce from road cars whatsoever, just a ferrari. sort of, even that doesnt produce downforce. infact, downforce is a myth altogether.
Quote from richy :This is why I find it hard to understand that no cars on the road generate downforce. Surely that designing and spoilers and smooth airflow counts for something. I dont see it adding to the lift so if it removes lift, thats as good as downforce?

Simply, the air over the top of the car moves faster (lower pressure) than the air underneath (higher pressure). Just as an aircraft wing works. Not hard to imagine why that happens if you look at an average car, like a mondeo or something, right?

High performance cars tend to have added diffusers and floor panels which accelerate the air passing underneath the car as quickly as possible. They do this because otherwise the car would generate excessive lift at the speeds the car is capable of reaching. Wings and spoilers tend to come next on serious cars, like with the Koenigsegg. If an average road car has a spoiler, it's almost invariably going to be fighting a losing battle, but that's not to say it has no effect at all.
yay finally a topic for bbt and me to resume our previous discussion ... where is he btw ?

Quote from tristancliffe :Ricers with wings just add drag, and probably some lift too. I doubt many, if any, generate any meaningful downforce.

there are some very ricy looking production cars that produce a sizeable amount of df with their wings though ... net result is still lift of course

Quote from Niels Heusinkveld :Ferrari probably uses the wind tunnel and computers to optimize the car body shape and most of all some underbody diffuser, accelerating the air out of the back.

quite the opposite ... its there to slow the air down

Quote from Bob Smith :Has anyone seen numbers on this? Ferrari told us this too but their telemetry data (apparently, I've not seen it personally) shows constant peak lateral gs at any speed.

the closest thing to actual numbers i have is some data for the 360 (almost the same shape) from mulsannes corner
http://www.mulsannescorner.com ... seferrari360modena99.html
Yes the wing on or off the car can produce real, measureable downforce. And you can refer to it as downforce.

But the car is likely to retain some lift (unless it's a very good wing!), and so the car is said have lift, albeit less. The car has no downforce.

Reducing lift at either end of the car, just like adjusting downforce on a race car, is usually to improve stability, so yes, that argument is correct.

But no one in the know will refer to a car that has lift, but also has a downforce generating wing, as a downforce car. For that to be the case there must a net, overall, downwards aerodynamic force acting on the car at speed. Which road cars, generally, don't have.
Do the cars in LFS without wings generate any downforce?
Quote from richy :Do the cars in LFS without wings generate any downforce?

Certainly not, and they technically should generate varying levels of lift, but I don't think they do. I remember it being discussed at length a long time ago though.
so even the xrt's spoiler doesnt push air up and add drag and do the whole downforce thing at speed?
Quote from Jertje :Can't it be said that the wing does generate downforce, but not enough to reverse the lift generated by the car? (thus giving the car less lift, but no downforce)

Or am I simply confusing myself now? ;p

It's a spoiler, and as I said, you can't really call it downforce, it just improves a flaw...

Think of it this way: Two identical TTs race each other (drag or full track, doesn't matter), the only difference being one has a better engine... Why did it win? Not because the one with the worse engine had to cope with more drag or friction (well, at least not in absolute numbers), but because it had worse propulsion, that's it... The same applies to downforce and lift... Just because there's less lift doesn't mean there is more downforce, if any...
Press 'F' to see the forces and there are one to three triangles (they are the light yellow/orange ones on mine).

The Formula cars all have three places with this arrow front, back are obviously due to the downforce/lift of those wings and there is one in the center as well. All cars have this center one, so it could be gravity, but I don't really know as it could be another downforce/lift.
If you drive two of the same road car, 1 with a wing and 1 without, the difference you would feel is the downforce or is that the misconception and really you feel the less lift? It is the same thing though right?
Quote from bbman :It's a spoiler, and as I said, you can't really call it downforce, it just improves a flaw...

Think of it this way: Two identical TTs race each other (drag or full track, doesn't matter), the only difference being one has a better engine... Why did it win? Not because the one with the worse engine had to cope with more drag or friction (well, at least not in absolute numbers), but because it had worse propulsion, that's it... The same applies to downforce and lift... Just because there's less lift doesn't mean there is more downforce, if any...

I don't understand at all how your example is explaining why two identical cars would be faster or slower due to lift if you just put a bigger engine in one... Obviously (if weight was the same) the one with the bigger engine would win (assuming traction was not breached with the lower powered engine).
Quote from blackbird04217 :Press 'F' to see the forces and there are one to three triangles (they are the light yellow/orange ones on mine).

The Formula cars all have three places with this arrow front, back are obviously due to the downforce/lift of those wings and there is one in the center as well. All cars have this center one, so it could be gravity, but I don't really know as it could be another downforce/lift.

LFS Cars with wing adjustments have three places that add downforce + drag: front wing, rear wing and undertray/diffusor.
as tristian has been saying road cars wings are "anti lift" devices
Quote from blackbird04217 :I don't understand at all how your example is explaining why two identical cars would be faster or slower due to lift if you just put a bigger engine in one... Obviously (if weight was the same) the one with the bigger engine would win (assuming traction was not breached with the lower powered engine).

1) read
2) comprehend
3) ???
4) profit

@richy: less lift is less lift. Full stop. Obviously, it improves handling, it CAN be due to something creating downforce (by itself) but doesn't neccessarily mean something creates downforce... Is it really that hard to grasp?
What forces apply to an anti lift device exactly, is that called downforce too or is that something else? A stabilising force
Quote from richy :What forces apply to an anti lift device exactly, is that called downforce too or is that something else? A stabilising force

One last try: You have two options to decrease lift - yes, one would be adding a device that creates downforce (on it's OWN)... The other thing would be improving the airflow over/under(/to the sides) of a car, which would only counter it's lifting tendency...

BOTH options would improve handling, BOTH would decrease lift, but only one would incorporate generating downforce, so you can't say it's downforce per se...
Less upwards force acts.

Take a car body => x amount of lift.

Change shape of body slightly, without adding any downforce devices => maybe 0.9x amount of lift. Zero downforce creating devices can do this (a spoiler is one example). They reduce the lift without adding downforce.

I can't believe you're still struggling with this. We're not even talking in detail, but in REALLY REALLY REALLY vague terms.
As mentioned earlier, there is a difference between a spoiler and a wing too. A spoiler is just a piece of some cheap material that has your favourite cup holder manufacturer's logo painted on it. A spoiler does not "create" downforce or lift but it creates drag. The difference between cheap and "good" spoiler is that the "good" was is "designed" to create as litle drag as possible. A good spoiler should not vibrate either at certain speeds, like some cheap ones might do. A spoiler is a chavving device.

A wing is an aerodynamic device that is put on a car to create downforce. A wing always creates drag and causes some aerodynamic inbalance in the airflow that leaves the wing. This is why it is important that to install your wings there where the air coming to the wing is "clean" to get most out of it.

Just like Tristan has said, the difference between downforce and lift is the wording. Saying an F1 car creates negative lift is as wrong as it would be to say that a jet engine creates negative drag

...
well as ive seen it, the spoiler acts as downforce if it reduces lift. I guess thats where im wrong.

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