ive seen a few pictures of 914's with this small rear spioler wing thing on the rear trunk lid

do those even create any down force?
is that down force that it would create necessary?

are they coustom made?
where would i go about getting one if they arent?
those things look pretty cool

The duck tail?

It doesn't do much of anything until you are going somewhat over 100 mph.


M

well seeing as how mine tops out at about...maybe...90ish down hill with a tail wind ...im not so interested any more

they are called duck tails huh?

still...where would i go about getting one?

Spoilers: disrupt the airflow over the rear decklid decreasing the chance of lift at the rear of the car.

Wings: create downforce depending on their angle of attack from the leading edge to the trailing edge.


B

thank you
so what one is this?

No problem. I was working with the wing today for our 993 CarreraS shop race car. Even with it set at ZERO.. it has 3degrees of "attack". It is a Porsche Motorsports wing desigined for a GT3RSR.. It will look KICK ASS mounted semi low on the back of the 993.

B

shaggy...it's a spoiler

Um.. is there a reason why I cant see his pic?


B

No pic attached...

Are you thinking the duck-tail, shaggy? Or a different one?

think its a duck tail

the name sounds right now that i think about it
i just think they make the car look cooler
so...ya im thinking about it...not really hard, but thinking no less...

im not sure if it was a duck tail
i first noticed them on the thread with all the 914 pics from the ventura porsche parts thing

If they are painted yellow, they make your car go faster!

Actually, most add them for looks. They do imporve air flow, but probably at higher speeds that you would drive on the street. An engineering student in San Diego was doing a study on the effects of spoilers for a class last year. Never hear/saw any results.

I have a NOS spare if you want to purchase one locally, or you can buy them from a number of vendors on line.

if your rear lid is nice don't drill a bunch of holes in it. rear lids can be had pretty cheaply. hard to go back once that first opening is reamed.

k

My duck tail does help, but it's the Sweeper Dam® up front that does the most.

No float at speed...


KT

He's obviously talking about it, look at it! It IS a 'rear wing thingie'... it's a layman's term.





M

ya thats it for sure!

guess i should work on learnin' all the correct trems

thanks for explaing that to me

-jim

IMHO the ducktail is there to cause a bigger vacuum behind the car. This helps suck air out from underneith the car, which in turn helps suck the car to the ground. From the people I've talked to, it's quite effective, but probably only worth doing if your into some kind of competition, or perhaps if you're just into pushing it all the time.

id like to eventually...after spending much time effort and hopefully not too much cash...have something that would be competition worthy...+ the duck tail just looks cool, the more i see it the more i like, but i dont really wanna drill a bunch of holes in my rear lid

As for drilling holes, if you are installing a spoiler. or anything for that matter, who cares?

Seriously...

If you like the way it looks, put one on , on a 914 for airflow, down force, or something else, you are wasting your time and money, racing or not. If you want to check it, tape short pieces of yarn to the back lid and slightly over the back of the car, and take a video. Then figure out if the down force is worth the drag. I Don't believe it is, but I think they look nice.
Take Care
Bill

QUOTE

wasting your time and money

I disagree.

Without the front "device", it floats all around.

The Sweeper Dam does work.


KT

I personally dont think the ducktail will do much for most cars...

On the track it is an advantage over nothing.. Not much though

But a wing would do the most damage.

Thats just my opinon, I have no facts.... Just observations..

(On that note, my car doesnt feel to sqirly at high speeds.. but on the otherhand... I havent had it up to 140......)

I think there is a big difference between airflow and downforce.
Airflow is where the air goes in resistance to the body, and downforce is the excess force that any piece of body creates on the car to aid in tracksion...

But downforce wont take much on the autox, but on the track I believe it helps alot.

A rear spoiler makes a huge difference in a high speed turn like turn 8 (100+mph) at Willow Springs International Raceway.

Yes, Dan is right, and he has the one that really works...Sheridan's SCCA legal rear spoiler. It looks good in red! My mechanic in LA has the original Sheridan prototype on his 914 racer.

The front dam definately does more than the duckie.

At around 120, a car without either gets interesting, but above 50, the dam makes a difference.



M

$80 at Tweeks

For the most part, it's going to be for looks until you get to much higher than average freeway speeds.

Be careful that you understand the difference between wing and spoiler. A wing will provide actual downforce (sacrificiing top speed for traction) and spolier disrupts airflow over the car.

QUOTE (Brad Roberts @ Oct 2 2005, 08:44 PM)

Spoilers: disrupt the airflow over the rear decklid decreasing the chance of lift at the rear of the car.

the ducktail spoiler is not about downforce. the turbulence it creates helps sucking air out from under the rear of the car, thus counteracting some of the "lift" you get at higher speeds ...

another thing you can do to help eliminating lift is running without the rear valance.

the effects can be felt at speeds well under 100mph ...
Andy


ducktail and cut open 916 rear bumper to help getting the air out from under the car ...

QUOTE (hmeeder @ Oct 3 2005, 10:27 AM)

$80 at Tweeks For the most part, it's going to be for looks until you get to much higher than average freeway speeds. Be careful that you understand the difference between wing and spoiler. A wing will provide actual downforce (sacrificiing top speed for traction) and spolier disrupts airflow over the car.

that style from Tweeks is great at lowering the value of your 914

1st, the ends rub/vibrate against the qtr panel removing paint....

then the holes that are drilled for mounting it to the decklid are souces for even more water to find it's way into the trunk...of course one good thing about them is that it makes good, straight, hole free rear lids worth more

Aerodynamic effects are not always easy to predict. Read a few books on auto aerodynamics and you will see that rear duct-tail spoilers mounted on a flat deck lid can do different things. The basic idea is to catch the airflow across the rear deck and generate a positive pressure over the rear deck which results in downforce. Within limits, the bigger the spoiler the greater the air presure. In the past before NASCAR went to common templates the Pontiac teams always complained that because their rear decks were shorter than the Chevys and Fords they ended up with less downforce for a given spoiler height. On cars where the rear airflow may be separating going over the rear roof and deck a rear spoiler can have the effect of raising the body work and allowing the air to remain attached, reducing drag. It all depends on what the air flow is doing with a particular car.

Wings are more efficient, but spoilers have been around since the sixties sports racers. If you look through some of the historical books on cars such as Chapparal, Ford GT, Shelby Cobras, or the Can-Am McLarens and Lolas you can see how the designers were trying to figure out how spoilers, front and rear, really worked. Modern sports racers like Audi R8s and Lola's don't use exagerated spoilers like they did in the past, because they try to find downforce in more efficient ways, but you can see Gurney flaps (small spoiler lips) used in many locations.

QUOTE (SirAndy @ Oct 3 2005, 09:43 AM)

QUOTE (Brad Roberts @ Oct 2 2005, 08:44 PM) Spoilers: disrupt the airflow over the rear decklid decreasing the chance of lift at the rear of the car. the ducktail spoiler is not about downforce. the turbulence it creates helps sucking air out from under the rear of the car, thus counteracting some of the "lift" you get at higher speeds ... another thing you can do to help eliminating lift is running without the rear valance. the effects can be felt at speeds well under 100mph ... Andy ducktail and cut open 916 rear bumper to help getting the air out from under the car ...

another thing you can do to help eliminating lift is running without the rear valance. "Right on Andy"

One area many 914 racers tend to overlook is the vacuum area just behind the targa top that is caused by the engine sucking in air and the chopped off rear window which is terrible for aerodynamics. If you can get rid of this vacuum, it is almost better than a wing as it helps reduce drag in a very big way. At one time I had an air deflector at the rear targa top edge deflecting air into this area but I have since lifted the top about 1.5 inches off the targa bar so that air coming in the windows will go out this slot I created. Seems to work as I get more air in my face now than before which is good for me and the rear of the car. Of course a better idea is to either make the car into a roadster or complety remove the rear window or use lexan and cut some holes in it.

hm... kinda thinkin against the tail now that i have heard its gonna cut my paint...
i dont have a rear valance now i was going to go get one at the junk yard and make it the right shape again

should i just leave is bare?

my parents complain about about the muffler looking crappy and "unfinished".
so is there some way i could make it look better and not have a real valance or should i jsut pick up a rear valance?

is there some way i could get a rear valance and like maybe say..."port it" with a hole saw or something?

Plan on racing the car or what?

You wont care about the paint soon...

It may be good for about 4 pounds of rear downforce at 0 mph.

QUOTE (shaggy @ Oct 3 2005, 03:09 PM)

my parents complain about about the muffler looking crappy and "unfinished". so is there some way i could make it look better and not have a real valance or should i jsut pick up a rear valance? is there some way i could get a rear valance and like maybe say..."port it" with a hole saw or something?

I'd just repaint your exhaust with some VHT paint and not worry about the valence...or if you want a valance, pick one up.
I have a triad, looks cool (sounds better), but I have yet to cut up my spare f-glass valence. I personally think the valence looks good on a street-car.
Basically do whatever you like, it's your car, good luck

Instead of the duck tail I would recommend you save up for some flares. They give no down force at all but sure look cool. Plus you can get really meaty tires!

I put the "cow catcher front air dam on my car and didn't have the duck tail. car was pretty well planted at high way speeds.
once I got home I put the duck tail spoiler on and car remained planted even at WAY over high way speeds.

One sad day a cone jumped out in front of my son and instead of taking a DNF he chose 2 seconds by hitting the pylon dead center. Destroyed the air dam. Drove home sans air dam and the car was quite a handful. put the orignal belly pan front on the car and it remained a handful at highway speeds. Took duck tail off and the car is better up to 100 then it is a real handfull.

of course toe out front and zero toe rear don't help either.