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Old 12-28-2015, 10:29 AM   #1
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Wing Blocker?

So I finally got around to pushing the button that raises the rear wing, and much to my surprise there is a plastic plate attached to the front that prevents any air from going under the wing. Googling images of other cars don't seem to show this; should it be there? If so, how does it improve traction?
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Old 12-28-2015, 10:40 AM   #2
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The "spoiler" dirtys the airflow over the back of the car to produce downforce at high speeds.
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Old 12-28-2015, 10:47 AM   #3
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I'll be darned.
Never heard of such a thing.
Your car must be broken. Probably.

Do both rear fog lights work? That's a common issue.
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Old 12-28-2015, 10:57 AM   #4
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the spoiler, also called an air dam reduces rear end lift by disrupting the airflow over the top and back of the car and thus reducing the tendency to lift at higher speeds. It is different than a wing which provides actual downforce.

Do a search and there are a couple of threads on this subject.

BTW, the spoiler will automatically go up around 75 mph and go back down around 50 mph
This is in the manual

Did you just get the car?
An intro with picture would be nice before posting questions
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Old 12-28-2015, 11:01 AM   #5
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Boxsters do not have a "wing". It is a spoiler. It provides down-force when it raises (automatically at about 75 mph), with less drag than a wing.

According to the owner's manual: "The rear spoiler reduces air resistance and, particularly at high speeds, reduces rear axle lift."

Some people don't like the way it looks, but it is effective and efficient. Aerodynamically it works much like a Gurney flap, with the rear of the car.

*I left the window open too long before replying and didn't see all the other replies. ...Beat that dead horse
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Last edited by 78F350; 12-28-2015 at 01:16 PM.
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Old 12-28-2015, 04:50 PM   #6
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I was Googling images, and although most with wings are obviously custom, I guess they are all custom add-ons. But there are a few that look like stock with the plastic bits taken off. OK, i'll leave it as is.

JayG, yes, I read how it works, but I am not tall enough to see it from the driver's seat. It was in the garage, and I had nothing else to do for a minute or so.

JayG, I will post an intro in the proper forum.
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Old 12-28-2015, 05:11 PM   #7
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Like the man said...

...it's a Gurney Flap.

What it does, is build a high pressure pocket of air as the airflow gets "dammed up" in front of the Gurney Flap.

The faster you go, the more high pressure air builds up in front of the spoiler, and the area of high pressure builds further forward until the entire top of the trunk to the back window is one, huge, high pressure air zone that pushes the entire back of the car down onto the pavement to reduce rear end lift, thus allowing you to maintain control at 160 mph.

The 986 Boxster is engineered so that there is more downforce on the rear, than the front as speed builds, thus promoting understeer in high speed corners for safety.

The Gurney Flap also reduces drag. The 986 has a .31 CD, which is pretty darn good for a convertible.

So, it's a very well engineered part, works great, and should be loved and admired and not messed with.

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Old 12-28-2015, 05:16 PM   #8
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^ What he said.

It's also a great place for a decal:
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Old 12-28-2015, 06:24 PM   #9
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Quote:
Originally Posted by 78F350 View Post
Boxsters do not have a "wing". It is a spoiler. It provides down-force when it raises (automatically at about 75 mph), with less drag than a wing.

According to the owner's manual: "The rear spoiler reduces air resistance and, particularly at high speeds, reduces rear axle lift."

Some people don't like the way it looks, but it is effective and efficient. Aerodynamically it works much like a Gurney flap, with the rear of the car.

*I left the window open too long before replying and didn't see all the other replies. ...Beat that dead horse
it does not produce down force, it reduces lift
It is basic aerodynamics.
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Old 12-28-2015, 07:15 PM   #10
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Quote:
Originally Posted by JayG View Post
it does not produce down force, it reduces lift
It is basic aerodynamics.
Not to quibble, but I used the term down-force, thinking that it would be more proper on a car forum than the aerodynamic term I would use at work, 'negative lift'.

Negative lift: An aerodynamic downward force created by any airfoil. /or/ The downward component (vector) of lift, relative to the body acted on by the airfoil.

Downforce (from Wikipedia) is a downwards thrust created by the aerodynamic characteristics of a car. The purpose of downforce is to allow a car to travel faster through a corner by increasing the vertical force on the tires, thus creating more grip.

There are other things we can call it too. I don't fault you far saying "it reduces lift", as that is one way to look at its effect on total force.
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Old 12-28-2015, 07:51 PM   #11
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as the shape of the car is basically a wing, the airflow over the car creates a partial vacuum which causes the car to want to move into the partial vacuum. that is caused by the airflow having to move faster over the car than underneath as it has a longer surface area to move over in the same amount of time.That is lift.

A spoiler disrupts the airflow over the "wing" and thus reduces or prevents the partial vacuum and therefore reducing lift

Downforce is the pushing down from an inverted wing and the same principle applies, just in this case the partial vacuum is on the lower part of the wing. that would be negative lift or downforce.

I guess you could say that reducing lift increases downforce, but there is no additional downward force generated, its just the weight of the car not lifting.

Of course all of this is ignoring any possible ground effect or any possible downforce from any front aero

you feel the lift usually in the front first as speed increases and the front of the car gets "lighter"

its a double edged sword as you want low drag, but low drag can cause lift and lift is not good as it reduces grip.
Reduced grip = less control
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Last edited by JayG; 12-29-2015 at 05:38 AM.
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Old 12-28-2015, 08:41 PM   #12
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As a glider pilot, I like the term spoilers.

Spoils the lift and reduces lifting of the rear end at high speeds in the Boxster.

The plate is part of the spoiler/dam that blocks the airflow.

Simple, effective and looks classy.

Younger folks and Racing types may prefer wings that actually use the airflow at high speeds to produce a down force, hence they have to be high up on the car to get into the clear airflow to be effective.

A low mounted wing is most likely nearly useless and mostly cosmetic.

The Race drivers know where they need to be, and they are alway mounted higher up.

Anyways, your spoiler works well as implemented unless you need extra rear end traction for racing.
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