Just an FYI, if a spoiler is producing downforce, it is increasing drag not decreasing it. Drag is a by-product of lift (downforce).

 

I am not sure, but I think Most spoilers on US spec cars are almost useless. A spoiler must be angled downward to produce down force, (like when the VR-4's active spoiler is downward)

Tuan Luu

 

no...
like you stated before... spoilers =downforce...
so lets say you have a rear spoiler on a FWD car...
where is the downforce that the spoiler adds going to take place?
in the BACK... so what happens to the FWD traction? it pushes down the back.. thereby lifting the front... where it then causes lose of traction for FWD cars.

if you want an effective spoiler for a FWD car.. you need to put them in the front... with a ground kit that has vents and crevices that will push the FRONT down... not some tail in the back...
so, any time i see a FWD car with a GT-R tail... you can usually see a big grin coming from me. =)

But now.. you may introduce looks and appearance... and the reason why people get these wings is for appearance.
Looks, are subjective... and if you put a spoiler on your car... in my opinion... is making your car 'look' fast.
so... e.g. see riceboy

 

Ferrari 360 = fast = no wing

-Stefan

------------------
3000gt@techdroid.net
http://www.techdroid.com/~3000gt/

 

not all spoilers are useless... they are designed in a way to produce downforce at higher speeds...

they don't have to point down to provide downforce...

Let's say a car is designed in a wind tunnel...
they find out how the wind arches around the car...
So lets use for example, the Supra... being a RWD car. They have to provide the supra with more downforce in the rear so the car can continue handing down the force at higher speeds. They track how the wind is going over the car... and design a spoiler right where wind is able to spoiled by the tail but not enough to cause excessive turbulence, thereby increasing the downforce.

again... I'm trying to use layman terms... and I might be confusing a buttload of people... but that's just me... stream-of-consciousness pacman. =)

 

Why everybody keep saying that spoilers are useless on FWD cars?
Spoilers do following things:
1. Reduce drag coefficient by arranging airflow behind the car.
2. Increase down force at higher speed. This compensates up force created by different airflow speeds under the car and above the car.

I guess this is not related to which wheels are providing the twist, because at higher speeds (when spoilers start working) it doesn't really matter.

 

Mark,

Spoilers _do_ reduce drag coefficient unusually by 0.01 - 0.02. Of course they have to be designed in proper way.
And yes, they don't have to be pointed down to create down force. Look at the back of your car. Air flows from the roof and it is directed backwards and slightly down. Then it meets a spoiler, which can be looked as pointed horizontally, but it is pointed down against the flow. Here we have down force. In addition spoilers prevent air to make twists behind the car. Here we have drag coefficient reduction.
All of this true for FWD cars. Just wonder how much power supped up Civic has to produce to loose traction at 100 mph?

 

without proper wind tunnel testing, and use on cars with a specific application (i.e. spoilers on a drag car need to be vastly different from one doing the land speed record, and also one in F1 racing where handling is critical), most bolt on spoliers are excess weight, and probably disturb the airflow more than they help it. if you like the looks, they are ok though :')

 

Not here to argue, but if a spoiler is decreasing drag, it is not producing lift (downforce). Increased lift (downforce in this case) as far as I know always increases drag. If you could increase lift and decrease drag at the same time, you could revolutionize the aircraft industry.

Look at the flaps on an airplane, they increase lift at a given airspeed but they induce a great amount of drag. They cannot increase lift and decrease drag at the same time.

Mark '96 VR-4
'96 YZF 600
Private pilot

 

Agreed, you learn this in "Fundamentals of Aerodynamics"


If you're reducing resistance (read: improving airflow) then you cannot be creating downforce. The act of changing the direction of the airflow causes resistance.

THERE IS NO REASON TO PUT BIG SPOILER ON FWD CAR.

The end.

-Alex 93 Stealth TT

 

i saw a program on tv about 3 yrs ago in which jay leno narrated as test drivers drove a 911twinturbo, callaway corvette, and a f50, in which jay said that the spoiler on the f40 creates enough downforce at 200mph that if the road were to turn over upsidedown, that the f40 would still stick to it!

give me a sec and ill find the pic for ya of the r/t from ocean city, who's is this?

------------------
rob schoen
http://www.detroit3si.8m.com/robs91rttt.htm
"parts will be in tomorow" ... ya right!




[This message has been edited by rob (edited June 09, 2000).]

 

Bernoulli's principle doesn't care if you are front wheel drive, rear wheel drive, or AWD.

Bottom line is this...When you have a lower pressure of air above the car than below, you have lift. You have downforce if the opposite is true. Drive configuration has NO effect on this.

Until you start getting into 3000+ horsepower drag rails, F1 cars, CART racers, et.al., I would not be overly concerned with where your engine is or which wheel(s) it is pushing, in regard to spoilers/downforce. There could be an advantage to having a rear spoiler on a FWD vehicle, though that isn't the case most of the time with today's vehicles...

Dan J

------------------
Dan J.
94 Stealth TT, K/N FIPK, Greddy Exhaust, Greddy Type S BOV, GTPro Y-Pipe, Centerforce DF clutch, Magnecor KVR 8.5mm's, PIAA Superwhite headlamps
System: Clifford Intelligard 700iq, Pioneer Premier DEHP900R, PD6 in dash changer, Macintosh MC440, a/d/s speakers all around...more to come!

 

Some people seem to be missing the point... Spoilers only help at high speeds. The little Stealth spoiler doesnt do jack. The 3000 spoiler might help more, but still, I dont think it adds more than 150 pounds of downforce at the ~140 top speed. Have you ever seen a FWDer smoke the tires at 80? No. So whoever seems to think it will take all traction away from the fronts isnt thinking logically. I find the car rather stable at high speeds, and I dont even have a spoiler. The fact is that the speeds the FWD is capable of dont even really require a spoiler to keep the car stable.
Yes, spoilers add drag NO MATTER WHAT CAR THEY ARE ADDED TO. Any spoiler made to create a force MUST use the drag force to 'push' off of. It is pretty cool how the formula one cars make like 6,000 lbs of downforce...yea they could race upside down, pretty intriguing really. Later, got class.

Jon Freedy
91 ES

 

Ever look at the Ligenfelter vette which can top 200 MPH? No spoiler cause the design of the body takes care of all the downforce, ie, the way the roof has a dip in it, the way the rear end looks and the way the bottom is shaped front and back. A spoiler has a tendency of reducing the bournoilli (sp?) effect at high speed, preventing the air from wrapping down under the the back of the car, and producing lift, taking traction off the wheels front or back. A proper set up has a balance with the front air dam and rear spoiler to create positive downforce and reduce this lift effect on the back (creates the backward swirl further away from the underside rear of the car). Cars aerodynamically designed correctly, do not require such contrivances, unless turning at high speed requires a great deal of downforce. Especially, on a very light car like Formula 1, or Indy, where downforce is required to double its effective weight going into a turn at high speeds. Nascar tracks are banked for this reason, so huge "wings" are not needed, but aerodynamics is set up to cut drag and create enough downforce on the rear so straightline acceleration does not cause the car to become light-assed.
On VR-4s, or SLs, spoilers of any kind are superfluous at speeds up to around 140-150 MPH. Beyond that, (I doubt an SL will see much more, cause a stock VR-4 has trouble doing much more)-no flames please! In fact, they probably do more harm than good at top speed attempts. They do make the cars more stable in turns and straight lines above that speed. More downforce means more stability and more drag (thats why our heavy cars feels so good in a straight line at 160-180) In wind tunnel tests, they try to make a body where the flow is laminar or sticks the air right to the car. They do not want the air to shoot up off the windshield and then fall back to the rear cause it causes a low pressure area above the car or lift. It is a compromise design for sure, because you want the profile of the car to be as winglike as possible, but to have downforce instead of lift.
We can not add a wing (mostly universal design) to the car and expect it to do what we want cause we do not have the right equipment to test it or an aeronautical engineering degree-PhD (most of us)to design it. Have fun...Big ass wings are in for the import crowd...if you are one of thos fans all the more power to you, do what you like. I like the way my car looks stock. All I plan to add is the Bozz Speed front chin extension just for looks and I am keeping my active aero cause I love waving good-by to the poor defenseless Honda Civics and Integras with the monster spoilers and cut coil springs.

Sam 95 VR-4

 

Drivetrain layout does not affect Bernouli's principle, this is true. Also, spoilers on any car short of a full race car provide little assistance in most cases. However, there is no aerodynamic benefit for a FWD car to use a huge rear spoiler, so why do it? At high speeds the right angle of attack from the spoiler will "spoil" the air and creat enough positive pressure above the wing to create downforce (i.e. the Active Aero wing at full tilt). Anyone with an Active Aero equipped VR-4 can feel this when the system is activated at high speed. One can feel the rear of the car being pushed down harder than with the system off. This does allow more traction for the rear wheels, especially in circumstances where the wheels have more opportunity to lift from the road surface. By this I mean turning. Having more downforce does equate with greater drag. A spoiler does NOT lower the drag coefficient. Whoever told you that doesn't understand aerodynamics or even basic flight principles. This reason is exactly why a VR-4 owner finds he can't get as high a top speed with the Aero spoiler tilted. The car will have greater rear downforce but extra drag, so the car will need to add an equal amount of power to compensate for this. Front surface area, or the actual area of a surface "attacking" or cutting through the air is directly related to aerodynamic drag. The more surface area, the more drag.

FWD cars can't possibly benefit much from a rear spoiler setup. I don't think anyone could be driving fast enough for it to make a difference either way, but that means its pointless anyhow. A FWDer wouldn't want to shift downforce to the rear, so the front air dam would have to be tuned to provide more downforce (if it is inadequate to start with). Combining a good front air dam with a rear spoiler is unecessary and only creates more drag. If the FWD car has a good front air dam or a good enough design that it creates enough low pressure underneath the car, why bother with drag producing wings? I can understand how someone might enjoy the look, but there really is no argument that a rear wing BENEFITS a FWD car in any way.


Jon -- '92 VR-4

 

The top pic is Johnny Blaze's car. He led the OC caravan from reading, pa. I don't particularly understand spoilers on front wheel drive cars. Downforce over the rear wheels will unbalance the car and reduce weight over the front wheels, the same as braking reduces weight over the rear wheels. This is why you see front wings on formula cars, to provide downforce over the front wheels.

The bottom pic is ehh i forget his name... but he had the other 99 vr4 at ocg. Careful what you say about that wing, or I'll run you over with it and you can feel the downforce for yourself

- cl2
Black 99 vr4 almost out of the friggin shop.

[This message has been edited by cl2 (edited June 09, 2000).]

 

I've seen some REALLY stupid things on cars (in my opinion) and will often make comments to friends that I'm with at the time about that. But I always say to myself, if that's what they like and it makes them happy then good for them. As far as the big spoiler (or anything else about the car) if it makes you happy then good for you. As far as the benefit of spoilers to any type of car at whatever speed, I think these are two completely different argument/discussions that have been mixed into one post.
Player--'92 3000GT SL
P.S. I personally am looking at spoilers to get one that is slightly different (for uniqueness) but not something that is huge and boxy. I want something classy that will compliment the car. I'm not looking for performance benefits, I don't have any way of calculating benefits of this type (as stated in an earlier reply). And if I wanted a VR-4 I would have one, but I want a transmission that works (no offense anyone). To each their own, and have fun guys, enjoy your cars and be safe.

 

The video Rob is talking about is ///Fast Cars (I got it on DVD) but it was originally a 1hour TV production... The Corvette in it sucked btw Calloway C7 or something. Early 90's Vette with a top speed at 177mph or something. It was the most litre-age and lowest top speed, heh. And they were talking about the F50 sticking to the road if turned upside down at 200mph, for what it's worth (The F40 only made a 5 second appearance as they showed it driving into the Ferrari offices. Gesseppi (sp?) was driving an F50 the entire time tho). That video rules. Calloway himself is a cool character.

--Steve "Loco3KGT" Gula

 

BTW, the McLaren F1 (240mph top speed) doesn't have a spoiler. 360 = fast = no spoiler ... F1 = Fastest Production Car in the World = no spoiler . I however, like the spoiler on my FWD 3000GT... and I ain't taking it off

--Steve "Loco3KGT" Gula

and that spoiler on the Stealth makes me laugh my ass off everytime ... when your front end starts lifting off at 120mph... you've effectively reduced your top speed.

 

The F1 does have a spoiler. Its not a wing-type that is mounted on the rear, but it is incorporated into the rear body. The same is true of the Supra and a couple other cars. If you look at the Supra, you can see the back has kind of a lip. It is very subtle but enough to serve a bit of a purpose. the F1's whole body is designed to be very aerodynamically efficient. There is a lot involved on that car that keeps it on the ground, like ducting on the bottom of the car to create low pressure. A huge wing would only slow it down because it would add a crapload of drag. I haven't seen a pic of an F1 in a while, but if memory serves, it has a bunch of air ducts/dams to control the aerodynamic properties of the car. It is one terrific automobile. I can't help but be reminded of the F-16, whose whole fuselage contributes to aerodynamic lift (the opposite of the F1 but similar in that the F1's whole body contributes to downforce and aerodynamic efficiency). I know I'm rambling and thinking out loud, but I hope some of what I'm typing makes some sense. Sorry if I'm "out there" guys...

Jon -- '92 VR-4

 

Even if our FWD cars are not pushing with the rear wheels. It only goes to reason that downforce on the rear wheels also cannot be a bad thing at 140+. I have been 140 in my NA FWD and I don't want either set of wheels lifting off the ground. Either way is going to cause bad results. I have the factory spoiler on the stealth. It does create downforce according to where it is located. More importantly it pushs down on the car directly over the rear wheels thus not "lifting" up on the front wheels. I think it is a perfectly placed spoiler. I am not as technically minded as many of you when it comes to principles and the physics of it. But my common-sense tells me that it can only help. Our cars have front spoilers. Granted they can be better but they are designed to create downforce up front also. Just my 2 cents.

LineNoiz

 

There was a very good article in one of the trade magazines about spoilers, wings and front air dams. I can't recall which mag. or what month, it's probably been a year or more. To make a long story short it stated..."nearly all front air dams are functional, almost all rear wings and spoilers are not. It went on to say that the only truly functional wing or spoiler was the whale tail on Porches, functional at almost all speeds. It further stated...then why do car manufactures put them on their cars? Because the consumers want them on their cars.