Some thoughts about Wings and Downforce

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So i was driving home the other day and pull up next to a riced up civic with a huge wing on the back of it. I shook my head and continued home not thinking anything of it. Later that night i was adjusting the downforce on one of my cars and it occured to me that seeing fins on front wheel drive cars is a really bad thing.

Here's the observation. Rear downforce pushes the back of the car down at high speeds and keeps it stable during cornering. Thats all good but in a front wheel drive car, it would seem that a moderate amount of downforce would actually reduce front tire grip potential. Unless you have really modified the rear suspension to compensate for it, you're defeating the idea of downforce.

Now here's another interesting observation. I own a 2000 celica and came across a widebody kit by APR. They have an interesting setup which has small carbon fins on the front of the car to increase front downforce. What an idea i thought and i wonder why more car companies arent lining up to modify fwd cars like this.

Here's an image that shows what im talking about.
widebody-celica-028.jpg


You can see the 2 fins on each side in front of the tire. Anyway just an observation that i thought was funny. GT really makes you think about how cars work, what a game :)
 
They're called "canards," and they do help to a certain extent, but only at speeds above those you'd drive on the streets. The majority of people I see with canards don't even have them angled appropriately to do anything but create parastitic drag.
 
Nothing is free.

The nature of lift (or in the case of downforce, "upside down lift") is such that as lift increases, so does drag. "Induced drag" is the drag generated from the actual production of downforce, and "parasite drag" (in its many forms) is the drag from an object being stuck out in the wind.

Canards have poor Lift/drag ratios. The amount of drag generated is relatively high, compared to the amount of downforce they generate - They do make some though...

A large part of front downforce comes from the airdam / splitter, which that celica is equipped with.

Allow me to, again, clarify some myths about wings. WINGS ARE NOT THERE TO ADD TRACTION TO THE "DRIVE WHEELS" TO PREVENT WHEEL SPIN DURING ACCELERATION!!1!one!!!11

VERY few cars have so much power that they can break traction from acceleration while traveling at a speed that results in the spoiler(s) being effective.

Aerodynamic aids on a car are there to add BALANCE and STABILITY at high speed, even on, yes, front wheel drive cars.

Because of a FWD car's tedency to understeer, most race setups on FWD cars have rear suspensions that are tuned for very strong oversteer. Extremely stiff rear sway bars, rock-hard rear spring rates - we'll call this "mechanical oversteer", but the result is a car that can get around tighter corners with a lot of rotation... FWD race cars can often be seen countersteering through an apex because their suspension setups are tuned for oversteer... to correct for the understeer under power.

HOWEVER, when the same car is traveling at 120mph, it NEEDS the rear downforce to keep it planted. The tendency to over-rotate, which was helpful at 40mph in the last hairpin, is now what is going to send you into the wall when you are trying to navigate the next sweeper at 100+ mph.

Wings, be them on the front or back, allow the balance to change as speed increases.

Of course, none of these principles were applied to your ricer :)
 
Thank you for explaining that so clearly, greyout. I've heard this 'anti-rice' argument many times, and you've corrected the mistaken assumptions very well.

The other thing to think about is this: Considering the car as a see-saw pivoting on the back wheels, how hard do you think you'd have to push down on the back bumper in order to generate any appreciable lift at the front end?

Right. Way more than a wing is capable of generating.

Now, when it comes to aesthetic wings, all bets are off. I happen to think it looks stupid and sloppy to see a touring wing bolted onto the decklid of a car and then left unadjusted so it's actually deflecting air down rather than up, but it's not really doing anything other than adding parasitic drag and wind noise at the speeds the car is likely capable of going.
 
Ya, great info greyout thanks for clearing up any misconceptions i had.

Duke, i hope you dont think my post was "anti-rice". I just think some people put things on cars that detract from function in lieu of "trendiness".
 
Vorian
Duke, i hope you dont think my post was "anti-rice". I just think some people put things on cars that detract from function in lieu of "trendiness".
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I'm anti-rice myself - it's all about function for me. If it looks cool also, fine, but I'll never compromise performance for looks.
 
APR cf parts are crap... the canards are just flat pieces of carbon fibre.. they used to have a pdf file on their site to give the exact dimension.. they are perfectally flat, you can make your own easily if you just go find a flat piece of carbon fibre. The most downforce you can get from an "add on" part for the front of the car is a front lip splitter... but a lot of these cosmetic/rice companies's versions of the splitter are just to cover up the tip of the front lip which is basically useless other than creating drag and a very disturbed air flow.

canards are widely used in the JGTC series.. and they are catching onto the american racing teams. A lotof these "trendy" parts are from the racing side.. peopel tried to make their car look racey.. one other thing now is tinted headlights.. im not taking about like darkened headlights, but like headlights tinted yellow or blue.. they are from race series like the le mans where different classes of cars are raced on the track at the same time, the different coloured headlights or lights distingish them from the different classes... and now people want to look like they're on the le man circute.. and have their headlights tinted
 
A large part of front downforce comes from the airdam / splitter, which that celica is equipped with.

How? I thought the airdam leads the air to the cooler/engine? (where the air get stuck; creating drag)
Do you mean the bonnet or the front spoiler?
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The part that creates the most effective downforce is the bonnet (Sp?) and the front spoiler, the rear wing has to be much bigger because they have to use the air which already was used by the front spoiler, the air is lesser compact and the rear wing has to collect more of that air to create roughly as much downforce as the bonnet/spoiler.

The front spoiler also prevents that too much air gets under the car decreasing the ground effect, so front parts are much more important than rear aero devices.
 
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