Most stock car racers already know that spoilers the size they use, on the rear have little effect untill up in the 150 mph neighborhood. Im also saying GENERALLY most Fieros wont do close to that. There are many now that will. My Ferrari kit easily would as well as Cal Kids. My V8 auto Fiero would not. Whether limited by gearing or rpm, I dont know, but barely ran 120...but got there quick . An old Nascar stockcar car can run into the wall and tear the spoiler completly off and still run pretty well if the rest of the cars pretty intact. Its not as critical as youde think.

quote Originally posted by AP2k: A poster above said it helps milage 1-2 miles, which is ~%3-6 depending on which transmission we are discussing. So %7 isnt negligible. Please dont be a fool and fall for the same thing others have. Spoilers are not meant to provide downforce.

You guys slipped a decimal point.... It's not 7/100ths, it's 7/1000ths or 0.7%.

At 30mpg, 0.7% is two tenths of a mile per gallon (not 1 or two miles per gallon.)

In other words, those numbers are well into the realm of noise, repeatability, and experimental error and are suitable for asterisked marketing fodder only.

quote Originally posted by Mr Schaefer: Not sure if it matters.. but the "poster above" was talking about a 1986 SE.. so a different spoiler on a different body style of car with a potentially different engine/tranny setup. If we're really looking at real-life effects of the spoiler on drag and aerodynamics and what that does to grip, performance and economy.. I would like to make sure we're all talking about the fastback body design with the GT-style spoiler.

Why? GTs werent the only Fieros to ever come with spoilers, not to mention the fact that it is within realm of possibility to *gasp* put one on a notchie. 1-2 mpg is very significant, especially on a duke engine which is already vastly more economical than V6.

If you want to keep it to fastbacks, go right ahead. I expect a full evaluation with lots of nubers, formulas, and colorful graphs by next week.

quote Originally posted by FTF Engineering: You guys slipped a decimal point.... It's not 7/100ths, it's 7/1000ths or 0.7%. At 30mpg, 0.7% is two tenths of a mile per gallon (not 1 or two miles per gallon.) In other words, those numbers are well into the realm of noise, repeatability, and experimental error and are suitable for asterisked marketing fodder only.

.7% less drag does not mean only a .7% increase in MPG. The almost 2 mpg statement by the "above poster" (me) was the result of driving a red 1986 SE (V-6 5speed) 355 miles with a wingless decklid, Then the winged decklid was swapped on and the car was driven back 355 miles with the cruise control set at 65mph. The decreased drag does have an effect on the highway MPG, at city speeds it has no effect.

It is well documented that the wing does reduce drag. It interrupts the air force moving up the back bumper and over the deck. Down force under 120 mph is negligible if at all.

And, yes, it is a wing, not a spoiler, but it is used like a spoiler for cosmetics. Go fig. eh GM?

When the wingstands are tall enough to move the wing up into the air stream it will behave like a wing. If it is kept at the stock location it behaves like a spoiler.

Interesting to note that when I swapped my wing for the Shadow spoiler, the air flow under the vents in the spoiler was very evident. I expect it functions almost exactly like the wing functions, but IMHO, it looks more up-to-date.

I tried the raised wing. At this height it still wasn't in the air stream. I thought it ended up making the car look too Taiwanese. IMHO



This is the way it looks now.



Same function, different look. For the difference in drag coefficient, if I wanted to go wingless, I would not hesitate.

Arn

quote Originally posted by Oreif: .7% less drag does not mean only a .7% increase in MPG. The almost 2 mpg statement by the "above poster" (me) was the result of driving a red 1986 SE (V-6 5speed) 355 miles with a wingless decklid, Then the winged decklid was swapped on and the car was driven back 355 miles with the cruise control set at 65mph. The decreased drag does have an effect on the highway MPG, at city speeds it has no effect.

If additional results can back up the claim that the simple addition of the wing can increase gas mileage 2 MPG then we can accept it as fact.. If this is factual information, then it's is puzzling why the large automakers have not embraced the principle and touted the mileage benefits of adding a wing spoiler. I am not saying that you didn't get better mileage after adding the wing, I am just questioning whether the wing, road conditions or climate had any influence. Aircraft acheive far better fuel economies flying West to East than East to West due to the movement of the gulfsteam air channel. Similarly a trip in a Fiero going with the wind is bound to produce better mileage and a route traveling downhill will do likewise. A trip in warmer weather produces different mileage figures as will a trip in humid vs dry air. If you removed the spoiler and ran the same route again under the same climatic conditions and the mileage decreased then we would have to agree that it does provide some benefit. Until such time as they say "I'm from Missouri".

------------------
87GT 3.4 Turbo- 0-60 5.2 seconds
2006 3800SC Series III swap in progress
Engine Controls, PCM goodies,
re-programming & odd electronics stuff
" I'M ON THE LOOSE WITHOUT THE JUICE "

quote Originally posted by Whuffo: The spoiler (and the whole Aero package) were developed for the Indy pace car effort. A regular bumperpad notchie has aerodynamic problems at high speeds, so some GM marketing money was spent developing a fix. The air dam on the front reduces lift at the front of the car - the spoiler on the back reduces drag. These changes allowed the specially prepared Fieros that paced Indy to lap at 135 MPH on that track. Yes, the spoiler works and there was wind tunnel testing done on the Aero package.

Yeah, that's what I was thinking.

quote Originally posted by Oreif: .7% less drag does not mean only a .7% increase in MPG. The almost 2 mpg statement by the "above poster" (me) was the result of driving a red 1986 SE (V-6 5speed) 355 miles with a wingless decklid, Then the winged decklid was swapped on and the car was driven back 355 miles with the cruise control set at 65mph. The decreased drag does have an effect on the highway MPG, at city speeds it has no effect.

I'm with Dennis. I'm not contesting your mileage numbers but what you've described above is interesting but anecdotal.

Was the ambient temperature, atmospheric pressure, humidity, and windage all exactly the same in both directions? Was the gross weight of the car, window position identical in both directions? Was there any cumulative altitude change involved? Was your gas formulation identical in both directions or did you fill up at completely different stations on different days?

quote Originally posted by Dennis LaGrua: then it's is puzzling why the large automakers have not embraced the principle and touted the mileage benefits of adding a wing spoiler.

Actually the large automakers HAVE embraced this principle. They did so by designing the whole body of the car to be aerodynamic. One aspect is look at the regular cars from the 80's as opposed to the mid 90's and up. Many of the trunk lids were raised higher and the rear windows have been integrated into them to reduce rear drag. They have advertised more aerodynamics and less drag for many years now. Sleek body styles, less road noise, and better MPG is still used in advertisements today.
Just instead of adding a wing/spoiler, They designed the entire body to reduce drag.

If you remember back in 85/86 Ford redesigned the Thunderbird body to be more aerodynamic by changing the rear window/trunk area which created an advantage for them in NASCAR. GM quickly took the Grand Prix and Monte Carlo and made a "2+2" version that incorporated the rear hatch from the F-body cars instead of the flat rear window until they redesigned the bodies of the cars in 1988.

So they DO recognize the advantages and have used them. Remember the commercials where they show the car in a wind-tunnel and the smoke trail showing the air passing over and around the car??? If I recall there are Chrysler, Acura, and Infinity commercials within recent years that used the same priciples.

quote Originally posted by Dennis LaGrua: If additional results can back up the claim..... If this is factual information......... If you removed the spoiler and ran the same route again under the same climatic conditions and the mileage decreased then we would have to agree that it does provide some benefit.

quote Originally posted by FTF Engineering: Was the ambient temperature, atmospheric pressure, humidity, and windage all exactly the same in both directions? Was the gross weight of the car, window position identical in both directions? Was there any cumulative altitude change involved? Was your gas formulation identical in both directions or did you fill up at completely different stations on different days?

If you guys have a problem or disbelief with the example, They by all means do the same experiment and please post your results. We can then accurately compare the three examples and provide additional data. Maybe we can get a few other folks to do the same and then have more data. That way we can also use the different body styles that were used on Fiero's as well. Why don't you guys organize such an experiment so that this thread can have an accurate scientific basis?

It's not like I am claiming 300hp out of a 250hp turbo V-6 engine without going to a dyno or something.

BTW ~ It was the same day and the same route when we did the road-trip. It was roughly 6.5 hours each way, Left at 5:30 am and returned around 6:30 pm. Late spring time frame in the midwest and we traveled south then north.
I honestly don't have the atmospheric conditions like temp, barometric pressure, and humidity.
However on the first part of the trip we went from 586 feet of elevation down to 415 feet of elevation.
Which means we went "downhill" first and "uphill" on the return. Thus making a winged notchback getting better mpg going uphill (on a 9.21e-5 grade) than a wingless notchback going down hill (on a 9.21e-5 grade).
We also started with Shell premium and ended with Mobil premium gasoline.

I just want to provide you with as much info as I can remember so you can accurately duplicate the experiment.

We just recorded the MPG out of pure curiosity. I did not think that 3-4 years later I would have to provide precise technical data in a thread about winged notchback Fiero's.

BTW ~ I do know that we were nowhere near the jetstream as we were on the ground in a car and not 30,000 feet above it.

Like I stated above, Do your own experiment and post your results.

[This message has been edited by Oreif (edited 06-28-2007).]

LOL

Don't shoot the scrutinizer.... It's all part of the scientific process. Problem here is you made a statement as though it were fact:

quote Originally posted by Oreif: The rear wing reduces drag. On a notchback it will increase highway MPG by almost 2 MPG.

But you don't have any scientific means to support that statement and as an engineer, it makes my warning go off. It was a neat test you ran, but the results you achieved may or may not have had anything at all to do with the wing. May have been the fact that it was warmer in the afternoon than the morning. May have been better gas. May have been one or two more top off clicks at any of the gas pumps involved...

quote Originally posted by Oreif:I did not think that 3-4 years later I would have to provide precise technical data in a thread about winged notchback Fiero's.

Heh... Exactly. LOL

BTW - I have a wing on my car and I'm not taking it off. I put it on because I like the way it looks.

ok, let's just call it quits with:

It may be a small help, it doesn;t hurt anything (except visibility), if you like it use it , if you don't like it leave it off.

simple. as was stated, no fiero is going to be driven at 120+ mph for any length of time, where it may have a more noticable effect, so real world use is covered safely in the above statement.
the increase in mpg may be true, the reviews and GM statements about the slight increase in aerodynamic efficiency would support that.
But wit the varying states of the fiero after 20 years, modifications, swaps, etc there are too many variables to really
form a scientific study. it would really be a single car statistic, only true for the car that did the test that day and can;t be carried over to another car and expect the same result.

quote Originally posted by FTF Engineering: But you don't have any scientific means to support that statement

Well actually there is scientific support.
It is a fact that the rear wing does lower the coefficient drag (CD) of the car. Which was verified by Pontiac when they wind-tunnel tested it. Less CD means less power required to move the vehicle thru the air at the same speed, Thus the vehicle would express this difference by decreasing fuel consumption resulting in better miles per gallon. In the specific case of my example it improved by almost 2 MPG. I never said that ALL notchback Fiero's with a wing would see a 2 MPG gain, But they all would see some gain in MPG with the decreased drag.

Reference's:

Mythbusters did a test on Pick-up trucks with the tailgate up, down, removed, and a webbed panel. They then monitored the fuel usage at 55 mph. The results found out the webbed panel reduced the drag of the truck the best and decreased fuel consumption. (better MPG)

Quoted from: http://en.wikipedia.org/wik...nt#Cd_in_automobiles

The drag coefficient is a common metric in automotive design, where designers strive to achieve a low coefficient. Minimizing drag is done to improve fuel efficiency at highway speeds, where aerodynamic effects represent a substantial fraction of the energy needed to keep the car moving. Indeed, aerodynamic drag increases with the square of speed. Aerodynamics are also of increasing concern to truck designers, where a lower drag coefficient translates directly into lower fuel costs.

About 60% of the power required to cruise at highway speeds is taken up overcoming air drag, and this increases very quickly at high speed. Therefore, a vehicle with substantially better aerodynamics will be much more fuel efficient. Additionally, because drag does increase with the square of speed, a somewhat lower speed can significantly improve fuel economy. This was the major reason for the United States adopting a nationwide 55 mile per hour speed limit during the early 1973 oil crisis as slower traffic would save scarce petroleum.

[This message has been edited by Oreif (edited 06-29-2007).]

quote Originally posted by Pyrthian: mostly cosmetic there is a slight areadynamic function in splitting the slow/backwards air which wraps up & backwards across the deck from the air going over the car. but, for a real "working" wing - look at any Fiero race car - Whale Tail. blocks the up & backwards air & makes the back deck a dead air pocket, and gives some downforce.

I hold an engineering degree as well and in engineering I have found that there is often a difference in the theoretical vs. the actual. That is why we see numerous design modifications on just about everything made. You design, then test, then the product is put out, then we determine if there are any flaws or improvements needed, then we redesign if necessary.
While much of the data presented here is good food for thought, I do not believe that we can draw a conclusion, that the simple addition of a wing can increase gas mileage up to 2 MPG. I cannot say that it won't but with just one test which was not done under controlled conditions you cannot state that it will. If it did there will certainly be a big run on wings.

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87GT 3.4 Turbo- 0-60 5.2 seconds
2006 3800SC Series III swap in progress
Engine Controls, PCM goodies,
re-programming & odd electronics stuff
" I'M ON THE LOOSE WITHOUT THE JUICE "

[This message has been edited by Dennis LaGrua (edited 06-29-2007).]

If everything could be worked out before production of anything, there would never be any recalls or failures. In fact what seems to be fact from an engineering standpoint may in fact (reality) not be even close. You can build 2 identical motors, in identical conditions and one will outperform the other. Simple comparison is just looking at any Nascar team. NO 2 cars they build will perform the same ever.

I bet a total of 2 spoilers, one under the tailights, and on the roof just before the notch on a notchback, would do wonders.

[This message has been edited by 2.5 (edited 06-29-2007).]

You know, after 2-pages somebody was going to say it. "If I was concerned about (drag coefficient)... I wouldn't be driving a Fiero." Hehe.

Anyone that feels the need to look out the back window, ain't going fast enough!

I set up my 88 notch duke for mpg one time and achieve 40 mpg,stock it does about 34 to 36 going over 70 the mpg drops seriously.. I am going to try again next year for 45 mpg at 65 i want 40 over 70!! I am interested in the spoiler wing which one would be best for m p g and easy to adapt to notch any coments,at this time I am destroying my exhaust system when i should be tuning for mid range,,with best wing,, i think 1 mpg is all I can expect realistically.. I was going with stock wing,any comments

If you are going for max gas mileage, you likely are looking at the good 'ol double nickel. At that speed, I just don't see any real advantage of going wing or spoiler. Tire choice is huge for gas mileage, as is alignment, engine tune, and believe it or not, clean and slippery paint.

The stock wing will do you as well as anything else for what you want IMHO

Arn

I understand that lower speed gives better mpg but want mpg at speed we can live with I do not drive fast but on the interstate I like to move with traffic,,optimum mpg for a 88 fiero duke notch is at about 40 mph i am a cheap skinflint and want fiero style while i squeeze that nickel Im saving in my pocket,, I no longer have an interest in powerfull engines which are mostly useless around town but are great to look at i hit the wall doing about 60mph on my ducati race bike years ago!! a month in the hospital took a lot of speed desire from me as my wife and 2 kids waited for me to go back to work ha ha stan 88 notch 4 86 G.T.

quote Originally posted by Arns85GT: Tire choice is huge for gas mileage, as is alignment, engine tune, and believe it or not, clean and slippery paint. Arn

Still true at 70mph too.

Arn

If your car is in good mechanical shape you will find the biggest single improvement in mpg by going to taller sidewall tires. like 70s or 80s series.( I think Ive seen 85 series tires?) Simple math that the taller tire will go farther per revolution giving higher mpg numbers. You will also lose some accelleration power in doing so.

quote Originally posted by rogergarrison: If your car is in good mechanical shape you will find the biggest single improvement in mpg by going to taller sidewall tires. like 70s or 80s series.( I think Ive seen 85 series tires?) Simple math that the taller tire will go farther per revolution giving higher mpg numbers. You will also lose some accelleration power in doing so.

Well if that was true, then my pickup with 36 inch tall tires should be getting 80 miles to the gallon instead of the 10 that it gets.

quote Originally posted by MP5Na3: Well if that was true, then my pickup with 36 inch tall tires should be getting 80 miles to the gallon instead of the 10 that it gets.

Huh???

"For those who understand, no explanation is necessary. For those who don't, no explanation is possible."

[This message has been edited by WAWUZAT (edited 06-30-2007).]

Well put on some 14" tires and see what happens to your gas mileage.........

Forgot...add 1000 pnds to the bed to offset the reduced tire weight

Anyone that graduated high school, knows from science and math class, the taller tire will go farther per rev. Put a 40" tire on a FIero and it will idle down the interstate lol

[This message has been edited by rogergarrison (edited 07-01-2007).]

Id be willing to bet not many fiero owners know that the air flows backwards over the rear deck lid and that the spoiler helps reduce the turbulence (vortex) of air spilling off the roof. The fireo spiler does not add any downforce at all, it only helps direct the air flowing up the rear of the car across the decklid toward the rear window.

quote Originally posted by 84Bill: The fiero spiler does not add any downforce at all,

Actually, it does-! It's called: the weight of the spoiler ! [/useless comment]

Yea, I saw that Mythbusters episode where they tested the pickup trucks. That was fun.

[This message has been edited by atleastitruns (edited 07-03-2007).]

quote Originally posted by 84Bill: Id be willing to bet not many fiero owners know that the air flows backwards over the rear deck lid and that the spoiler helps reduce the turbulence (vortex) of air spilling off the roof. The fireo spiler does not add any downforce at all, it only helps direct the air flowing up the rear of the car across the decklid toward the rear window.

That's what I figured. Kinda like the air pocket created on top of the bed of a pickup truck. I always thought that the back of the notchie Fiero (if you imagine away the GT sail panels the fastback does too) has elements of pickup truck design. (Vertical back window and flat area behind it, then mostly vertical dropoff at the end of the car) Mythbusters explained the vortex created in such a situation.

quote Originally posted by Fierari: It makes the notchbacks look better?

That it does IMHO. Fastbacks look really clean without the spoiler. I wish it had one of those spoilers on modern cars that only activate above a certain speed, or under hard braking ( - to keep the back end planted. ) Cars like the: Audi R8, Chrysler Crossfire, Mercedes SLR, Porsche 911 -something rather, etc.

Most of these cars also have a manual override, that lets one raise the spoiler/wing with the push of a button.

[This message has been edited by Austrian Import (edited 07-03-2007).]

What I said.............see I even agree with Bill sometimes.............LOL

quote Originally posted by Dennis LaGrua: While much of the data presented here is good food for thought, I do not believe that we can draw a conclusion, that the simple addition of a wing can increase gas mileage up to 2 MPG. I cannot say that it won't but with just one test which was not done under controlled conditions you cannot state that it will. If it did there will certainly be a big run on wings.

So have you done your own testing yet??
As you stated one test doesn't give you enough data and I offered to have you do a controlled test so we can compare them.
Please post your data when the testing has completed.
Thanks.

When i removed my wing for looks, i like wingles notchbacks the decklid light would go on every now and then. Above 50 mile or so my decklid light would go on blinking a little. On the highway it was on almost all the time and at low speed it was always off. So i guess the wing did very little but something

quote Originally posted by Strider: AP2K Do you have wind tunnel evidence to back this claim up? I would like to believe that spoilers on the average production car do something besides add drag but some how I don't think that the companies put that kinda of Wind tunnel time in.

Funny you mention that, but I've seen many pictures of clay Fiero models in the wind tunnel with the smoke test. Simply having the co-efficient of drag numbers (back then) shows you that they did actually design the car using a wind tunnel. Now, it's certainly not the same level that Formula-1 teams use... but it's still in the wind tunnel.

------------------
Todd,
2006 Pontiac Solstice
2004 Volkswagen Beetle Convertible (Wife's Car)
2002 Ford Crown Victoria LX
1987 Pontiac Fiero SE / V6 (3.2) 5-Speed
1984 Porsche 944 5-Speed
1981 Pontiac TransAm (Olds 455BB)
1973 Volkswagen Type-2 Transporter

When Big Ed Parks was putting what was left of my Indiana 88 GT back together with his Alabama chassis, he called to ask if I wanted a clean deck lid or the wing version. I left off the wing. I think it looks better, but there is one big hazard - be careful that the lid does not hit your nose when you open it! The springs were set for the lid + wing weight!

------------------
John W. Tilford

.

[This message has been edited by atleastitruns (edited 07-07-2007).]

quote Originally posted by rogergarrison: Most stock car racers already know that spoilers the size they use, on the rear have little effect untill up in the 150 mph neighborhood. Im also saying GENERALLY most Fieros wont do close to that. There are many now that will. My Ferrari kit easily would as well as Cal Kids. My V8 auto Fiero would not. Whether limited by gearing or rpm, I dont know, but barely ran 120...but got there quick . An old Nascar stockcar car can run into the wall and tear the spoiler completly off and still run pretty well if the rest of the cars pretty intact. Its not as critical as youde think.

from what I found out, high performance track/road race cars (I don't know anything about Nascar cars) are set up to oversteer at slow speed. Skilled drivers want the car to turn on a dime and navigate hairpins. They can catch a possible slide before it's unrecoverable. The wing (some spoilers accomplish the same thing by redirecting airflow behind the car) is designed to push the back end down at high speeds (at slow speeds it's ineffective.) and therefore make the car neutral/understeer slightly, as at higher speeds 90+mph, oversteer happens so fast, that even skilled drivers aren't able to correct for it quickly enough to avoid a spin.

I hope that helps.

It makes it look like a Korean car.