Adding a SPOILER! Will it help or hurt?

[texan]

Originally posted by Veetec
I´m not sure about this because I don´t like most of the aftermarket spoilers and wings and personally I would never buy one => I never cared or thought about that! But somebody told me that the wing of an ITR for example will help you while cornering because of the additional pressure on the rear tires! I can see his point but I dunno why a daily driver should be equipped with one because IMO it´s really unnecessary. Like most of the other aftermarket parts.

His whole point was that fwd cars are traction limited at the front, not the rear. There's no point in increases rear end traction on these cars, all you are doing is increasing aerodynamic drag (very few aero parts have a positive side effect to drag).

[Veetec]

Originally posted by texan


His whole point was that fwd cars are traction limited at the front, not the rear. There's no point in increases rear end traction on these cars, all you are doing is increasing aerodynamic drag (very few aero parts have a positive side effect to drag).

Yea, I know! I know what the point in here was. I`m talking about the guy who told me the thing with the ITR and he wasn´t talking about traction on the front. Of course a wing doesn´t help the traction of a ff car.

[CornerCarver]

Originally posted by Veetec
Yea, I know! I know what the point in here was. I`m talking about the guy who told me the thing with the ITR and he wasn´t talking about traction on the front. Of course a wing doesn´t help the traction of a ff car.

The ITR is front wheel drive.

[LjasonL]

if u watch fwd touring cars, those cars have rear wings, it is to keep the rear planted during high speed cornering, so there IS a purpose to a wing on an fwd car, but the car must be cornering VERY fast, and the suspension must be tweaked. a standard fwd car has loads of understeer, and a rear wing will only complicate this problem.

[VTEC_boi]

Originally posted by ldelaysionl
if u watch fwd touring cars, those cars have rear wings, it is to keep the rear planted during high speed cornering, so there IS a purpose to a wing on an fwd car, but the car must be cornering VERY fast, and the suspension must be tweaked. a standard fwd car has loads of understeer, and a rear wing will only complicate this problem.

I was under the impression that FWD cars have OVERsteer problems?

Am i wrong?

[texan]

Originally posted by VTEC_boi


I was under the impression that FWD cars have OVERsteer problems?

Am i wrong?

Understeer = Front end traction is lower than the rear, causing the front end to swing wide during cornering.

Which is exactly the problem you naturally run into on a front heavy, front wheel drive car (especially on corner exit with throttle applicaton).

[VTEC_boi]

Oh..alright

thanks Texan!

Sorry ldelaysionl!!

peace
boi

[pushVTEC]

When you are getting a spoiler the last thing you should be worried about is it's "downforce" capabilities. You are driving a FWD car... therefore the downforce created on the back of the car wont do anything since all your power is coming from your front wheels. With a spoiler you're looking for style not functionality

[911GT2]

Originally posted by CiVTEC
More info:

Look at the Ford Focus RS, that wing does work!
http://www.fantasycars.com/1/News/Fo...fordfocus.html


A front lip (airdam) is actually more helpful since it prevents a lift force being generated from beneath the car.

Actually, I'm working on designing a simple solution to creating nonturbulent flow to the rear spoilers on any car. I will have it patented and it will sell like hotcakes in the aftermarket departments...make me rich!

The large majority of wing buyers are riceboys. Riceboys don't care about performance and will therefore not even consider your product no matter how good it is. And a flattened wing (which most aftermarkets are) will not give you downforce one way or the other.

And putting downforce on the rear of a FWD car will give you horrible high speed stability.

[pushVTEC]

Talk about bringing back a post from the dead lol

[Flycyhm]

Wow, am I sorry I missed this one! Go for a few weeks with out the internet, and look what I miss!

So is this all settled now or what? Personally, I think the guy who mentioned the point about the rear spoiler or wing (both do it) increasing the laminar flow characteristics of the air leaving the trunk and reducing drag (also reducing the dirt on the back of the trunk due to the vortices circulating dirt and debris against the car) had a good argument, and no one seemed to acknowledge it.

That is really what all the factory ones are for, with the exception of some very expensive high end sports cars. The rest are just for looks.

Damn, sorry I missed this. I just did a lot of aerodynamic modifications to my aircraft (I'm an Aeronautical Engineer and Pilot), and I love a good debate.

Hopefully someone else will come in and stir the pot too!


Flycyhm

[DGooden]

I think adding will be cool. It'll look cool and worth the money IMO

[Chris]

well, I posted this a long time ago, i feel it is a good explanation:

A spoiler can add drag (porsche 911 turbo, the 'whale tail' years).
A spoiler works on the Coanda effect. That is, air (or any gas or liquid) flows along like the surface it was on. Therefor, on a car, it goes DOWN the back, meeting the air from the bottom. This increses drag, but the air moving that way kinda (a little bit) decreases lift. Now, as far as I understand it, a spoiler causes the air to go up momentarily, flowing STRAIGT behind the car, not as much going down. This decreases drag. Now, the air UNDERNEATH the car has to come UP to the rear of the car, increasing the distance it has to travel, and therfor increasing speed and decreasing pressure going up (lift).
Now you see how it works. (they are in capitals just to highlight important stuff, not trying to make you look dumb. I have done that unintenially in the past )

That is a spoiler, the small 'lip' thing on the back of a car. It has nothing to do with aviation (actually, it does, but not for this reletively simple stuff)
A wing is a device that is an upside down airfoil. It decreases lift, but increases drag. If it is small enough, the drag will be slight. Sometimes it can actually decrease drag by letting the air out quicker and more efficiently. This all depends on a gazillion factors that are hard to understand.

Most magazines call small wings spoilers, which they are not.

Heres another example. On the 911 Turbo, it has a spoiler at first. Then it rises up into uninterupted air, in effect a wing. A true definition is hard to come by, as most people us the terms when they shouldn't.


Also, ALL cars now have spoilers. Look at the back of any car, I did today. From Fireflys to Minivans to corvettes to Ferrari 550's, all cars have them, because they work. Most aren't very defined though, but then they don't need to be.


I find wings to be useless for almost all street cars. Especially on front wheel drivers. The last thing you want is downforce on the rear, unless you commensurately increase the downforce on the front. And you wont need that extra downforce on your average honda. It will just cost money, increase noise, increase air resistance (slower), etc....

[texan]

Originally posted by Chris
A true definition is hard to come by, as most people us the terms when they shouldn't.

Good post BTW, not that many people know about Coanda (ever see the Cobra Daytona Coanda rearend?). But regarding the above qoute, I'll qoute myself from much earlier in this post... "And to clarify the difference between a wing and a spoiler, a wing is any airfoil with airflow over two sides, a spoiler only has airflow over one."

[Chris]

I alwayss get excited when the server works, and I can do something, so I didnt read the whole thread.
Thanks for the compliment, tho
And in a R&T recently, they had an article by one the head designers of the Cobra Daytona. He took most of his ideas from an obscure German guy of about 30-40 years earlier. No one his Cobra design would work, but it did.

And regarding surface area increasing drag; a good general rule, but almost never true. F1 cars have a very small cross-section (area if it were a rectangle), but they produce much much more drag than the largest SUV. THis increase downforce for due to way they are setup, but this is just an example.

If you take an aerodynamic course in University, you will learn that there is no definite formula to determine air resistance, it is done experimentally in wind tunnels (now, CFD is taking over, tho). Still, it is a very interesting area, which often involves a little bit of black magic.