Are OEM wings/spoilers functional?

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Very interesting info coming from you guys the knowledge base on this forum runs deep.

thank you

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[souleux]

The primary effect of the vortex generators on the Evo were to maintain the boundary layer of air going over the car so that the point of detachment on the rear glass was lower on the glass than without the VG, which then provided more airflow underneath the stock rear wing, and thus more downforce. Without it thanks to the sharp angled drop-off from the roof to the rear glass the detachment point messier and higher. Additionally there was a slight drag reduction. So overall it made less drag for the car, and more rear-end downforce, with the small increase in weight from the plastic, which ended up being an excellent trade-off. There's a whitepaper from the Mitsu engineers on their design, experiments, and results somewhere...

Subaru did the same thing with the STI and its spoiler. Also here is a test they did on the STI and EVO in a wind tunnel.

EVO/STI wind tunnel tests - TunerNetwork.com - Your Performance Tuning Community

 

[ACM]

I pondered the same question regarding the boomerang on the back of my 98 Talon - right up until the first decent snow arrived.

Then I watched the air start to clean off the sides of the spoiler by the time I reached highway-legal speeds, and the middle didn't clean off until I reached racetrack speeds. Even then, I suspect it vibrated off rather than anything else. Closed course testing of course !

One easy test for the 97+ Talon boomerang is to place your pinky over the central support and then press down - notice how the hatch metal flexes ? That pinky pressure is more downforce than the wing actually generates at triple digit speeds, otherwise there would be lots of drivers with dented hatches every time they came back from the track

Best guess is that the engineers spend more time making sure the aero package does nothing negative to the car, rather than something useful. Front end aero typically focuses on reducing the +ve pressure buildup under the nose, but not much else at our price point.

 

[jtmcinder]

That the wing isn't enough to generate a *net* downforce is almost irrelevant. Given that the slope of the hatch is such that - without a wing - it would definitely produce lift, the question is whether - with a wing - it generates *less* lift, not whether it generates actual downforce.

As to the snow clearing off the sides before the middle ... now you know why the Evo X's wing is shaped as it is. What I am often amused by are cars with the same sort of wing, but raised 18 or more inches up off the trunk. Once that high, the flow is straight over, not in from the sides, so the three-zone wing is no longer rational.

 

[ACM]

You're missing my point Jtoby- there's no airflow at all under or over two thirds of the wing until triple digits. Were there any airflow it would remove the snow. If there's no airflow under/over it, I don't see how it could affect the car aerodynamically.

 

[jtmcinder]

How air flows when it is being blocked is not a good predictor of how it flows when it isn't being blocked. Thus, what areas had snow cleaned off at whatever speeds is not the way to determine the answer to the OP's question. Much better would be a string-tuft test; best of all would be force transducers. Anything less than these is darned close to bench-racing aerodynamics. My point above was intended to be more general: whether you get a net downforce is not how you determine the effectiveness of a wing or spoiler.

 

[BIGBLAZE79]

i'm a pretty clear communicator. I don't "mean to say" things, i choose my words and type them.

rofl

I can tell you that the stock spoilers on a 1G do their thing pretty good.
The reson you guys can not feel the difference is: you are not going fast enough!

I drove a 1G with spoiler and without on the german Autobahn.
Cornering without a spoiler at 120+mph is VERY scary, the back is just feeling lose.
When it comes to breaking its even more frighting.

A 1G with stock spoiler is easy to control at high speeds.
120mph Autobahn corners are no problem. Also cornered with my 1G at 170mph, still feels pretty stable.

I guess dragracing can easiely done without any spoiler but "time attack" should be done with a spoiler.
I would suggest to keep speeds below 130mph when driving without a spoiler.

I would agree with you, My buddy took his stock spoiler off his 93 RX7 doing prep for paint. A week later spun the car around on the freeway going 100Mph. He said he went to change lanes and the back end just kept going. He hit the wall and totalled the car. It was daytime, dry out and light traffic.

 

[arrowhead]

If we're looking at stock spoilers and their actual effect on aero I think this could be a decent discussion. But it doesn't belong in the Appearance forum. I'll move it to the Road Race forum, as requested by the OP.

The problem is testing. There's a really good article in the May 2010 Grassroots Motorsports mag that has some tips on how to do testing on page 49. I'd highly recommend picking up a copy:
May 2010 Issue: Grassroots Motorsports Magazine

For those of us who don't have access to wind tunnels, these tests would be a good way to see if our aero mods are helping or hurting us.

Great magazine I had let my subs.expired many years ago when got away from racing I just renew and ask for a copy of the one you mentioned.


Thanks

I can tell you that the stock spoilers on a 1G do their thing pretty good.
The reson you guys can not feel the difference is: you are not going fast enough!

I drove a 1G with spoiler and without on the german Autobahn.
Cornering without a spoiler at 120+mph is VERY scary, the back is just feeling lose.
When it comes to breaking its even more frighting.

A 1G with stock spoiler is easy to control at high speeds.
120mph Autobahn corners are no problem. Also cornered with my 1G at 170mph, still feels pretty stable.

I guess dragracing can easiely done without any spoiler but "time attack" should be done with a spoiler.
I would suggest to keep speeds below 130mph when driving without a spoiler.

Your personal experience and first hand info is very helpful.
Did you tried changing angles or only tried it in stock location?

thanks

Could it be that the different types used on our cars are the results of experimenting by the factory until they arrived at the 2gb, maybe by changing the angle it could be more useful.

I know that angles are a trade off between drag and downforce.

For drag racing I think the wings they used are more towards keeping the car straight and little downforce where in road racing it, the opposite may apply.

A fast sweeping turn where the car is being upset by the change of direction and having the tail end up in the air is not fun at all.

 

[snooopy365]

Your personal experience and first hand info is very helpful.
Did you tried changing angles or only tried it in stock location?

I just compared with and without.
And with wing but without rear wiper, but it hard to tell any difference, maybe it is a bit more stable without the wiper (btw. hole covered!)

 

[drivemusicnow]

This car will probably run a class known in SCCA as STO and I quote from the GCR.

Wings shall be a single element with a maximum chord length of 12.00 inches, including any wicker.

Not wider than 72 in or width of body whichever is the lesser.
.
The entire rear wing assembly, including the end plates and any wicker, shall be mounted level with, or below, the peak of the roof.

Wing end plates must not exceed 144.0 square inches.

Your original question is are the OEM wings functional. The OEM spoiler on a 1g is functional as has been mentioned above. You're kind of asking if you can modify the stock piece to be more effective, and I'd respond with saying that's mostly a waste of time. Keep it there, but leave it alone as the benefits would be very minimal.

The rule book you quoted above is allowing a pretty significant wing. By significant, I meant both in size, and effect.

When looking at the "best" wing for your car, for road racing, as allowed by the rule book, there are two things to keep in mind. 1) All dsms suck at downforce in the front. If you add a huge wing to the back and don't do anything for the front, it'll just understeer like a pig. Considering the drivetrain of both AWD and FWD cars already cause the car to inherently understeer (for the most part, up until the point where you reduce grip in the rear to force it to oversteer) this is generally not all that helpful road racing.

2) Downforce is one way to increase grip. There are other ways that may be much much simpler. If you really really want to go with a wing, basically maximize the width, chord length, and height that the rules will allow, and then use one of the many NACA wing profiles that are well known. Then, build yourself adjustable mounts that give you the ability to adjust the angle of attack of the wing, which will allow you to adjust lift and drag on the car so that you can optimize it for the airflow over the car... Or will at least allow you to tell other people you can.

BTW aerodynamic people typically talk in terms of lift (Specifically, negative lift) which can be confusing when someone says "Blah blah creates 260lbs of lift" because they really mean "blah blah creates -260lbs of lift" aka downforce.

Oh, and you don't need a super expensive wing to make significant downforce. You can buy a super cheap wing that uses a NACA profile, or even better make a wing, for your car with really good success. They key is to really look at the recommended angle of attack to mount the wing which drastically changes lift and drag characteristics. There are pretty basic CFD softwares out there including javafoil that if you're a total nerd like me, you'll play around with for hours getting almost no useful data out of, and then just buy an off the shelf wing with a known NACA profile anyway.

 

[arrowhead]

Hey thanks for your reply.
My original question was if they were functional or not.

I understand there is a delicate balance between front and rear and a lot of RWD cars also have a tendency to understeer, I dont know yet if I may even use one specially on tight small tracks, and since I have a 2gb wing, although my is a Talon, or maybe just go with a small spoiler which can be made adjustable and try it.

I think there is a lot of different opinions if they work or not.

I am not going to waste my time trying to design my own like you said and then going out and buying an aftermarket one.

Thanks for your reply.

 

[troppo loungo]

Many of you are forgeting the other purpose for the stock spoiler, sporty looks. Do you think a 4cyl pontiac grand am or sunfire sport edition had a spoiler to improve downforce or stability? Given this point I don't believe the stock spoiler is very functional. The 1g being now 20 years old, I don't believe there was a lot of effort put into downforce on a dsm, it was mostly for looks. The car was designed to have 195 hp on the street. Not 500hp on a race track. I'm talking about the dsm specifically and excluding serious sports cars. Today aerodymics are more important to maximize fuel economy (all cars) and high speed stability and handling (true sports cars).

I agree that the front end needs to be addressed first if looking to imporve road racing aerodymics and downforce on a dsm. The first thing is to get more air to flow over the car by preventing it from going under it. Therefore a deep air dam combined with a splitter is the best thing you can to. The next thing is closing up all the front end gaps and holes (other than needed for cooling). With more air flowing over the car (downforce) and less flowing under the car (reducing lift) this will increase front end downforce considerably. Devices such as fender flares and canards can be of some benefit as well.

A rear wing works best when its in clean air, out of the vortex, therefore you want it higher but there is always the balance and trade off between downforce in the corners and top speed on the straights. It depends on the track and the cars dynamics.

I often thought of adding a vertical piece to the pack edge of the stock 1g spoiler to add some more rear downforce, similar to Nascar but only a few inches tall.

It is difficult to generalize on what works and what doesn't on RWD, AWD, FWD because it depends on what else has been done to the weight balance, suspension, power and driveline.

 

[thomcasey]

For the 1g's, I would think they are more form than function. Take the top line GSX/TSi AWD/Laser RS-t AWD and compare them. They are all rated the same in every aspect, yet all the spoilers are DIFFERENT. If it were for function, I highly doubt they would all function exactly the same to produce the same results with three different designs??

 

[snooopy365]

In germany, 1g's without the aero parts (Lip, side skirts and spoiler) is rated to be 10km/h slower.
It isn't just for Show, it does reduce drag andere creates down force. Because of the fact that the spoiler is pretty much at the end of the car, it does prevent air from forming turbulence. That turbulance would lift the car up and pulling it back (that is why the car gets faster with a spoiler).

 

[Lofty]

This is cool information, do you have any proof they're rated slower than ones with aero?

 

[snooopy365]

Yes I do have proof.
This is the german owners guide:

You must be logged in to view this image or video.

let me explain with some word to word translation:
Fahrwerte means driving data
Höchstgeschwindigkeit means topspeed.
oder stands for or
the *below is a extra comment why there are two topspeed values.
*Fahrzeug mit "Aero-Zubehörteilen" means: Car with "aero-parts"

btw. they only sold the GS here so all the data are EU spec GS.
And yes there are 4WD GS! but they are very very rare.

 

[arrowhead]

Very nice info, we may have some function on these wings after all.

Do you have anything similar for the 2g.

There are no problems or difficult questions as far as front spoilers, closing all the holes, adding a splitter like most race cars are doing and eliminate the flow under the car, all of it will help with the downforce, but something has to give for the rear
be it the stock unit or a replacement.

To me all the wings they have used on the dsm look out of place and do not go well with the lines of the cars, so maybe they saw some function to them since they knew what these cars were being used for.

 

[snooopy365]

Sorry I don't have anything about the 2G aero parts.
But honstly, when the designed the first gen spoiler with a reason. Why should the use 2G spoilers for looks only?
Maybe that is true for the Eagle, that car was never sold to EU so they don't care about topspeed and topspeed stability.

 

[eclipsegsx1736]

The OEM 2g "turbo" wing certainly has the correct cross-sectional shape to produce negative lift. The top surface is flat, while the bottom surface has an airfoil shape to it. You will see this same design on the Evo 8-9 rear wings.

Just from eyeballing it, the majority of the wing also appears to be in an area that would receive at least some airflow as it comes over our (rather low and smooth) roof/hatch.

 

[Mrdocprofessor]

On eccomodders.com in the aerodynamic section they have a tinplate you can use to see if the wings are functional or not if you do check it out you'll see that they are not ideal for less drag or more downforce

 

[Viva]

I am in. School for high performance and the only spoilers that really work are about 5 inches below or higher than the roof. Unfortunately for all of us dsmers that make our cars look clean, our wrap around 1g spoilers and 2g spoilers are dead weight :-(. But wind splitters and such affective Diffusers are the really only possible way without having shamoo as a car. (Big effin wing).

 

[arrowhead]

On eccomodders.com in the aerodynamic section they have a tinplate you can use to see if the wings are functional or not if you do check it out you'll see that they are not ideal for less drag or more downforce

I am a little confused by "they are not ideal for less drag or more downforce", are you talking about all dsms or wings in general, by the way, there is a lot of good reading on that web page.

I am in. School for high performance and the only spoilers that really work are about 5 inches below or higher than the roof. Unfortunately for all of us dsmers that make our cars look clean, our wrap around 1g spoilers and 2g spoilers are dead weight :-(. But wind splitters and such affective Diffusers are the really only possible way without having shamoo as a car. (Big effin wing).

A lot of times in a race car things may not look clean, as in some of the time attack cars, and as stated before they may be for looks only, from all the different types of dsm wings, one has to be more functional than the rest even if some mods have to be done to it.

 

[Flash]

Someone needs to do the fuzzy string aero test and drive down the highway.

 

[arrowhead]

Someone needs to do the fuzzy string aero test and drive down the highway.

Excellent idea, I would do it on mine but the car is being built, a video would maybe help a lot.

Happy thanks to everyone

 

[jtmcinder]

Just from eyeballing it, the majority of the wing also appears to be in an area that would receive at least some airflow as it comes over our (rather low and smooth) roof/hatch.

Do not underestimate the amount of air that comes from the sides of the car and joins the air coming down the hatch and all ends up around the wing.