Are OEM wings/spoilers functional?

[arrowhead]

I know this has been talk about before but from what I can find only from the looks point of view.

Any of these spoilers functional, as far as down force, and if yes, which one please.

Only the stock spoiler not replacements.
Thank you

 

[2GbTalonGuy]

I have always wondered how much downforce they actually provide. All of the 2G spoilers seems to do next to nothing. They all either seem too flat to do anything or too low in the airstream to do any good.

 

[Bud92gsx]

I'm actually suprised that there has been no test on the spoilers.Especially with all the people in the dsm community..

 

[ricktb]

From what I understand about the air flow over the top of your car, is that it follows the curve up your front windshield, and depending on speed will either curve back down the back windshield, or create a backwards spiral of drag vorticies off the top edge. The stock 2gb spoiler probably creates a tiny amount of downforce, or drag at the least (decreased fuel effeicency) considering the angle of the wing to the direction of air flow. At high speeds probably not a whole lot of downforce since most of the wing is engulfed in the drag zone. You'd want one wider and taller for greater effect, might as well get one with adjustable angle. Note the awd version is prone to oversteer

 

[arrowhead]

I dont see any relation between being a FWD or RWD for the real function of a wing.

I am also surprise no one has tested this out.

This is for a RR car I am building and yes it will go over 100 mph. Depending on tire size and final gear ratios and all else that is involved we may reach maybe 140-160 on the straights especially if we run the long course at Homestead or Daytona.

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.

So now having this info are they anywhere functional or maybe by doing some mods to it make them work.

Thanks for any input

 

[LandoAWD]

Unless you wind-tunnel the car or can properly calculate downforce with an equation I'm not familiar with, it'll just be a park bench, regardless of make.

 

[TSITurbo95]

Unless you wind-tunnel the car or can properly calculate downforce with an equation I'm not familiar with, it'll just be a park bench, regardless of make.

 

[arrowhead]

Unless you wind-tunnel the car or can properly calculate downforce with an equation I'm not familiar with, it'll just be a park bench, regardless of make.

Do you mean to say that a rear wing does not create downforce or that is useless on any application.

 

[GsXdSmKingGsX]

Do you mean to say that a rear wing does not create downforce or that is useless on any application.

He's saying if you're going to do it, test it properly in the wind tunnel to prove that its functional and not just a giant piece of aluminum sitting on the back of your car adding weight. We dont know if its going to work for your application yet so prove us wrong.

 

[LandoAWD]

Do you mean to say that a rear wing does not create downforce or that is useless on any application.

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

 

[arrowhead]

I am not trying to prove anybody right or wrong, I am only asking for info and that is all.

Do you any ideas how much a wind tunnel would cost?. I am sure is beyond my reach.

thank you

 

[LandoAWD]

It's all good, I just want to make sure I'm clear.

Andrew Brilliant has spent some time in a wind tunnel, maybe see if you can eek a response out of him?

 

[T is for TURBO]

I am sure is beyond my reach.

Yes it is.

Wind tunnels are expensive research facilities, usually built by automotive and aerospace industries, and universities. They aren't going to just let anyone drive their jalopy in to test a couple factory spoilers.

That is, unless you make a fat donatation.

 

[dsmTripp]

I dont see any relation between being a FWD or RWD for the real function of a wing.

Well the difference between fwd and rwd when it comes to a rear wing and down force is simply put... rwd has all the power going to the rear wheels thus down force is needed to keep the power to the ground. That being said rear down force on an fwd is kinda pointless. Now if you were to move the spoiler to the front of an fwd like one of the pro scion TC cars people will laughing at you as they did him but you will get results. Hope that help a little bit in differentiating between fwd and rwd and the rear wing

 

[EDM95]

There is a difference between a spoiler and a wing. A spoiler is actually built onto the car, while a wing stands off of it. A spoiler's primary function on the back of a car is to reduce drag and reduce lift. A wing can reduce lift and increase down force.

 

[TSiAWD666]

If you're looking for a serious wing you could talk to Dave at DHP Composites.

DHP Composites - Carbon Fiber Wings, Carbon Fiber Splitters, Carbon Fiber Panels

Incredibly nice guy, great communicator, and really knows his stuff. We've already generally worked out mounts for the 2g hatch. There are pictures of my wing in the High Downforce thread as well as in my gallery. You could change the uprights and width to your desired size of course, or go with my exact wing, though it's 70" wide designed for a wide body. No one else, as far as I know, produces a wing already designed for the 2g.

Here it is actually installed, but it's wrapped up to protect it while the body work is occuring:
<img src="http://www.dsmtuners.com/gallery/files/2/0/6/0/0/photo_3_83307.jpg" alt="Body Work Update - Oct 18 2011" />

Here's a pic when I received it and taped it in place just to check fitment:
<img src="http://www.dsmtuners.com/gallery/files/2/0/6/0/0/photo_2_1.jpg" alt="My New Wing From Dhp Composites - July 2011" />

Unless you wind-tunnel the car or can properly calculate downforce with an equation I'm not familiar with, it'll just be a park bench, regardless of make.

Some equations, or really an area of mathematics/engineering that you might not be familiar with that is commonly used to estimate aerodynamic performance is Computational Fluid Dynamics.

Computational fluid dynamics - Wikipedia, the free encyclopedia

 

[arrowhead]

Hey some very nice photos and nice looking car MY original question was about the stock wings or spoilers that come originally on the dsm independent of year or model and asked if they where functional or mostly for looks, as of now I have been sent to a wind tunnel, that they are a waste, and they are not needed on a race car.

Is the tunnel on your car extended to the front sure would like to see more pictures of that, what is the use of your car solo, drags it looks too clean to be a RR car, very nice looking.

I will be looking at your bodies web site, it really looks good and FUNCTIONAL



Thank you very much

arrowhead

 

[gusu]

Generally, stock spoilers are designed to REDUCE drag to increase top speed and gas mileage. Usually they try to defuse as much air as possible.

The other reason for factory wings is to keep the car going straight at high speed, not by down force but by changing the way the air is pulled by the car. This is exactly why the STI has such a large rear wing and why the 2007 STI came with a smaller spoiler on the rear windsheild and still has the huge ass wing.

If you were to test it, I would bet that it actually reduces drag.


If you want to test this. You can make a water towing machine at home (pain in the ass but you can), add dye in the correct places. Run the water and watch the dye, it does the same thing as a wind tunnel. But it is cheaper, you can make it at home, and all it takes is a correct scale model and simple math. But you wouldn't even need the math and exact numbers because the way the dye flows makes it pretty obvious to be honest.

The hardest thing to do is find a scale model that is accurate. There are some scale models out there that are pretty accurate.

You'd also have to know how to modify a water towing machine to work more towards the middle of the tank rather than the top.

You can also build a wind tunnel at home for a bit more, you'd need a good smoke machine as well as electrical skills. Of course this would be a small one for scale models. But, aerodynamics does not always scale. However I should mention it wouldn't matter since you aren't calculating any numbers. You are just trying to find out if it adds/removes drag or does nothing at all. You could easily see that with either method.

I actually had a class in high school where we made a small wind tunnel and had to make a paper plane that could fly straight on a string. The box was easy, the paper plane was like having your nuts in a vice.




Example. http://coolschoolprojects.com/wind_tunnel.html

 

[Boostinsideways]

Gusu, some of those rear diffusers/wings also just help keep the rear glass clean. My 4.3 Blazer had one on it specifically to keep the rear window clean. It diffused the air around the back door to keep dirt and shit off there. The thing on evos does much the same thing, but also helps with straight line speeds.

 

[TSiAWD666]

Gusu, some of those rear diffusers/wings also just help keep the rear glass clean. My 4.3 Blazer had one on it specifically to keep the rear window clean. It diffused the air around the back door to keep dirt and shit off there. The thing on evos does much the same thing, but also helps with straight line speeds.

On the Evo it was not designed with the intent of keeping the glass clean. I can't say in my personal experience owning an Evo IX for five years that it's ever noticeably had a clean rear window relative to other cars I've owned, but I've never driven the car without the vortex generator.

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...

I really don't think your Blazer has anything close to the vortex generator configuration of the Evo 8/9 but... maybe it does. Interesting that yours is to keep the window clean or that you think that's what it does. /shrug

 

[Ludachris]

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.

 

[Zdrummer15]

On the Evo it was not designed with the intent of keeping the glass clean. I can't say in my personal experience owning an Evo IX for five years that it's ever noticeably had a clean rear window relative to other cars I've owned, but I've never driven the car without the vortex generator.

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...

I really don't think your Blazer has anything close to the vortex generator configuration of the Evo 8/9 but... maybe it does. Interesting that yours is to keep the window clean or that you think that's what it does. /shrug

^This is correct. Just in case this gave the OP any ideas I'll add that things like vortex generators won't do much for cars like ours because we don't have that sharp drop off like an Evo or other sedan at the rear window. Being that ours are liftbacks, they have a much more gradual decline from the roof height.

 

[snooopy365]

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.

 

[Boostinsideways]

I really don't think your Blazer has anything close to the vortex generator configuration of the Evo 8/9 but... maybe it does. Interesting that yours is to keep the window clean or that you think that's what it does. /shrug

The diffuser on the blazer was far to small to produce any kind of vortex, which would be useless anyways on a flat back vehicle. It did keep the window clean, as I took it off because I thought was stupid aftermarket crap the previous owner had put on. It was off the vehicle maybe a week and the back glass was so dirty it was hard to see out of.

Take the vortex generator off your evo and I bet you will noticeable dirt accumulation on the back glass if your ever on dirt roads. Why is it so hard to believe that it can serve more than one function? The RS does have the Vortex generator, and not the wing, and was sold with racing purposes in mind. The Vortex generator arguably does more than the wing. And realistically a rally team would put a more functional spoiler on the car.

 

[jtmcinder]

You don't need a wind tunnel. You just need a couple of force-transducers and a PC (both of which I own, but I no longer have a DSM).

As to vortex generators ... I think one of the funniest things I ever saw was a set of those on a 2G. The hatch produces a very smooth flow all the way to the tail (as verified by fuzzy-string tests). Putting on a set of Evo-style vortex generators was less than useless. But, man, they made the car fast when VTEC kicked in ... not.