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Re: Do spoilers work?
#142662
10/29/08 12:00 AM
10/29/08 12:00 AM
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Joined: Aug 2006
Posts: 247
DuPont, Washington
DZJim
enthusiast
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enthusiast
Joined: Aug 2006
Posts: 247
DuPont, Washington
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Quote:
This one really made a difference in holding down the front end. The Chally used to get very light in the front over 100mph. Added this in front and a TA spoiler in the rear and at 140, it is still very stable.
Wow! Now there's a speedbrake (airbrake for purists) if ever I saw one...
http://en.wikipedia.org/wiki/Lift_dumper
http://en.wikipedia.org/wiki/Spoiler_(automotive)
Can't imagine an airfoil attached to a car making much difference for anything important at legal highway speeds. Looks kind of cool though, I guess. I'm sure Walter Mitty would have had one. Could have gotten one on my new Corolla last winter. Figured it was plenty fast enough as it was... 
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Re: Do spoilers work?
[Re: DZJim]
#142663
10/29/08 12:11 AM
10/29/08 12:11 AM
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Joined: Jan 2003
Posts: 5,275
near Harrisburg, Pa
440trk
master
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master
Joined: Jan 2003
Posts: 5,275
near Harrisburg, Pa
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The first production car to ever receive a factory installed spoiler, was the 66 HEMI charger. The 66 spoiler is relatively small...but made a WORLD of difference at the track. If memory serves, a vehicles aerodynamics start to have a noticeable effect at speed above 60mph. That would mean that the spoilers are JUST starting to be effective at about 60mph...so any speed over that, they should indeed be functioning. That being said, the drag and weight associated with spoilers will indeed SLOW down a car a little...but you're trading speed for stability. 
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Re: Do spoilers work?
[Re: DZJim]
#142664
10/29/08 12:14 AM
10/29/08 12:14 AM
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Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
70Cuda383
Too Many Posts
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Too Many Posts
Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
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I always thought spoilers on cars were ineffective until around 70 mph.
however, they do say that it's more fuel efficient to roll your windows up and turn the AC on as low as 45 mph.
as posted, spoilers are no more than airplane wings. except they are upside down to produce downforce instead of upforce (lift)
lift causes drag, no way around that. the more lift a wing makes, the more drag it's going to have.
think big heavy cargo plane. the wings are so thick (I can almost stand up inside a B-52 wing at the wing root--I know because I've been inside the fuel tanks), that they produce massive lift at low speeds. they also produce lots of drag at low speeds. that's why cargo planes are slow.
think of an fighter airplane wing. very thin, and sleek. (I probably couldn't even fit inside an F-16 wing) they produce almsot no lift at slow speeds, and need to travel much faster to produce lift. but, it's their mission to fly much faster, which is why they have such sleek thin wings.
so, the shape and design of the spoiler will drastically affect the amount of downforce and drag it will make.
I think an AAR/TA rear spoiler will produce more downforce and drag than the sleeker go-wings that stick up off the trunk lid.
but, I don't know, and have no real world numbers to support my claim.
there are other ways to improve handling without adding drag inducing spoilers though. simply lowering the car will lower the center of gravity, allowing it to handle better, AND by lowering the car, it allows less air to get trapped under it at highway speeds, which means less air pushing up on the car from the bottom, so by simply lowering the car, you get less drag, and better handing.
**Photobucket sucks**
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Re: Do spoilers work?
[Re: 70Cuda383]
#142665
10/29/08 07:36 AM
10/29/08 07:36 AM
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Anonymous
Unregistered
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Anonymous
Unregistered
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my chin spoilers are effective in directing small nighttime critters into the lane next to me when I clip them.
other than that, they look really cool
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Re: Do spoilers work?
[Re: 70Cuda383]
#142666
10/29/08 08:12 AM
10/29/08 08:12 AM
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Joined: Dec 2003
Posts: 22,696
Bitopia
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,696
Bitopia
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Quote:
as posted, spoilers are no more than airplane wings. except they are upside down to produce downforce instead of upforce (lift)
Sorry in our applications, a spoiler is NOT a wing. They may both develope downforce, but they achieve that completely differently. And in laymans terms, a rear spoiler causes a build up of air pressure on a surface upwind of the spoiler mainly by inducing drag, and a rear wing causes a pressure differential on the wing surface by causing different air speeds above and below the wing. They both will induce increased downforce or uplift as desired, but they are not the same. 
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Re: Do spoilers work?
[Re: 340SHORTY]
#142668
10/29/08 12:48 PM
10/29/08 12:48 PM
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Joined: Jun 2005
Posts: 230
FL
shupe
enthusiast
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enthusiast
Joined: Jun 2005
Posts: 230
FL
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Quote:
I heard a story that the Sbird/Daytona wings didnt do much tiil around 100 MPH,, but at 200 MPH they produced 600 FT LBS of down force..
.
What I've read is it was the bad aero of the 68 B bodies that led to the Wing cars. Richard Petty built a 68 RR racecar and was testing at Daytona. When he shut it off on the back stretch for plug check, it didn't even make it around to the pits coasting. They knew they had aero problems then. IN addition to the wing, the nose of the wing cars is what they needed.
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Re: Do spoilers work?
[Re: ThermoQuad]
#142669
10/29/08 12:59 PM
10/29/08 12:59 PM
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Joined: Jan 2003
Posts: 27,468
So Cal
autoxcuda
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 27,468
So Cal
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Quote:
Spoilers work, i have real world data...
There is real numbered data in the 69 Car Life spoiler article. They hooked up cables to the suspension and measured the spoiler vs no spoiler differences. The also did rear only, front only and both combinations.
Cars tested GTO (rear only), Javelin SST (rear only) and Camaro (front and rear). Camaro started showed a difference at 70 mph.
The rear only setup was the worst. Because it pushed down the rear and they pushed up the front at the same time. So the rear only actually created MORE front lift!
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Re: Do spoilers work?
[Re: shupe]
#142670
10/29/08 12:59 PM
10/29/08 12:59 PM
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Joined: Dec 2003
Posts: 22,696
Bitopia
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,696
Bitopia
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Quote:
Quote:
I heard a story that the Sbird/Daytona wings didnt do much tiil around 100 MPH,, but at 200 MPH they produced 600 FT LBS of down force..
.
What I've read is it was the bad aero of the 68 B bodies that led to the Wing cars. Richard Petty built a 68 RR racecar and was testing at Daytona. When he shut it off on the back stretch for plug check, it didn't even make it around to the pits coasting. They knew they had aero problems then. IN addition to the wing, the nose of the wing cars is what they needed.
On a simliar note, I read somewhere in the past that on a typical fully winged Indy style car, if shut off at high speed will deaccellerate at a 1G rate from all the induced drag from the bodywork/wings, since in their case downforce is so much more important then reduced drag numbers.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
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Re: Do spoilers work?
[Re: jcc]
#142671
10/29/08 01:44 PM
10/29/08 01:44 PM
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Joined: Nov 2007
Posts: 21,822
Kirkland, Washington
Pacnorthcuda
Too Many Posts
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Too Many Posts
Joined: Nov 2007
Posts: 21,822
Kirkland, Washington
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Quote:
Quote:
as posted, spoilers are no more than airplane wings. except they are upside down to produce downforce instead of upforce (lift)
Sorry in our applications, a spoiler is NOT a wing. They may both develope downforce, but they achieve that completely differently. And in laymans terms, a rear spoiler causes a build up of air pressure on a surface upwind of the spoiler mainly by inducing drag, and a rear wing causes a pressure differential on the wing surface by causing different air speeds above and below the wing. They both will induce increased downforce or uplift as desired, but they are not the same.
 Spoilers and wings are two very different animals. Spoilers are relatively simple 'wind deflectors', a Wing, since it has air flowing over and under (and a shape, perhaps a true aifloil, like a Go-Wing) is a much more complex device.
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Re: Do spoilers work?
[Re: autoxcuda]
#142673
10/29/08 07:20 PM
10/29/08 07:20 PM
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Joined: Jul 2005
Posts: 757
Toronto, Ont, Canada
boydsdodge
OP
super stock
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OP
super stock
Joined: Jul 2005
Posts: 757
Toronto, Ont, Canada
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Do you guys know where any of that data is hidden? I like to do modifacations to my car that actually work, not just bling. I would hate to find out after drilling through some clean sheet metal that I end up hurting the ride rather then improving it. 
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Re: Do spoilers work?
[Re: boydsdodge]
#142674
10/30/08 03:31 AM
10/30/08 03:31 AM
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Joined: Jan 2003
Posts: 27,468
So Cal
autoxcuda
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 27,468
So Cal
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Quote:
Do you guys know where any of that data is hidden?
I like to do modifacations to my car that actually work, not just bling.
I would hate to find out after drilling through some clean sheet metal that I end up hurting the ride rather then improving it.
69 Car Life. I have the magazine.
Ducktail spoilers work (T/A, AAR, 67-69 and 2nd gen Camaro, 2nd gen Firebird). Air dams/front spoilers work. Wider and closer to the ground the better.
The rule on stock cars (including Cup) is something like sealing the front to 1/8" to touching the track compared to 1/2" off the track is like DOUBLE the downforce !!!
A significant part of the reasoning on the current soft spring/big bar/big shock setups is to get the nose sealed to the track. So the car passes minimum ground clearance in tech, then goes into the first corner, slams to the ground against the bumpstops, and the huge rebound shocks "tie down" the nose to the track and keep down until it exits the turn.
Turn middle-entry. -Notice with all the various 4 corner suspension travels, the side rails are almost level and close to the track. 
Turn exit
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Re: Do spoilers work?
[Re: boydsdodge]
#142676
10/30/08 10:39 PM
10/30/08 10:39 PM
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Joined: Jan 2003
Posts: 20,765
A collage of whims
topside
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 20,765
A collage of whims
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Real-world experiences: '64 Corvair, light in the nose @ 65MPH; added 1-st-gen Z28 ft spoiler, problem solved. '65 Belvedere A/FX car, 157MPH max at the stripe no matter what; added 3" spoiler to trunk, 45* angle, went almost 170. Turned out it was a lift issue, causing tirespin. '73 911, similar issue as Corvair, added 911Turbo ft spoiler, worked as on Corvair, but rearend got looser. Needed Carrera ducktail spoiler or Turbo spoiler to balance; fairly common experience among 1st-gen 911 owners.
Note the early TransAm cars; those spoilers were considered mandatory by the teams for aerodynamic benefit.
The idea is to minimize air under the nose (lift), air getting under the car (drag), and to get the air onto the trunklid (lift) and reduce turbulence behind the car (drag). The effects are generally measured and noticeable at highway speeds in the dozen or so articles and tests I've read. Should be easy to google the info.
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Re: Do spoilers work?
[Re: boydsdodge]
#142680
11/02/08 12:31 AM
11/02/08 12:31 AM
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Joined: Jan 2003
Posts: 27,468
So Cal
autoxcuda
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 27,468
So Cal
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Quote:
Do you guys think that the factory front spoilers used on the T/A perform a function, or would I have to go with a one piece spoiler as large as the one that Booster has on his car? (the red Challenger pictured above)
I'm sure they help some. But if they were just continous across that would be better.
Booster's spoiler I would think is better than a 67-69 Camaro spoiler. But that is a fiberglass spoiler and it sets lower and more forward than a stock T/A spoilers. I would think it would help radiator cooling also.
Here's one on an AAR. Al is super super careful but still has cracked it a couple times.
http://www.transamcuda.com/spoilers.htm
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