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Old 12-09-2014, 09:05 AM   #601
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Well it's not very TOP SECRET now is it!!!
Now that... is a terrible joke.
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Old 12-09-2014, 10:21 AM   #602
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chevy isnt going to sell a car to the public that makes the majority of its downforce from under effects. Its exceptionally dangerous, see the lotus 79; kerbing, dips, and other surface imperfections were a good way to find yourself spinning off into the armco after loosing the majority of your downforce. Its the reason limits got put on under body aero in NASCAR back then.
fixed it for you.. Ferrari would do that. top gear considered, they got to beat the mclaren p1 for bragging rights. anyway the fxxk is only going to see a track, as the people who buy them can't actually take them. Ferrari delivers it to a track, lets them play around, and takes it back to maranello.
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Old 12-09-2014, 10:23 AM   #603
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K
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Old 12-13-2014, 10:35 AM   #604
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CFD, wind tunnel testing, blah blah. Does anyone just have lap times under same conditions comparing their car with spoiler vs wing? Surely someone must have done it.
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Old 12-13-2014, 10:42 AM   #605
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How effective do you guys think these wheel vents are? I feel like it's mostly for looks with some function.
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Old 12-13-2014, 11:49 AM   #606
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Originally Posted by MX5JER View Post
CFD, wind tunnel testing, blah blah. Does anyone just have lap times under same conditions comparing their car with spoiler vs wing? Surely someone must have done it.
Of course they do. And the answer is...










Google it.




They do two different things. Spoilers reduce the speed of the air moving over the trunk surface, thereby reducing the lift created through the principle identified by the 16th century Swiss mathematician Bernoulli. A rear "wing" is an airfoil making use of the airflow to generate force exerted downward. So, essentially one eliminates lift and the other creates downforce. Both actually make use of Bernoulli's principle but in different ways.
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Old 12-13-2014, 11:53 AM   #607
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They do two different things. Spoilers reduce the speed of the air moving over the trunk surface, thereby reducing the lift created through the principle identified by the 16th century Swiss mathematician Bernoulli. A rear "wing" is an airfoil making use of the airflow to generate force exerted downward. So, essentially one eliminates lift and the other creates downforce.
And you have totally missed my point. I don't care if they rely on gravitonic anomalies or Voodoo. At a grassroots level of design and fabrication, what comparative impact have they had on laptimes? That's really all that matters.
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Old 12-13-2014, 11:58 AM   #608
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It depends on your horsepower level and the particular track. A big ******* wing will make slower laptimes on a faster track if you don't have the horsepower to overcome the drag created at high speed. So the answer is math.
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Old 12-13-2014, 12:22 PM   #609
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No, you just don't understand the question. The answer is not math. Because the question wasn't what will work for me. The question is what have others found in their own experiences? Which may or may not apply to my situation. Now some will take the position that they did the work and cost and choose to keep the info to themselves. Go pay to find your own answers. Totally justifiable. But others don't tend to think that way.
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Old 12-13-2014, 12:33 PM   #610
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Quote:
Originally Posted by MX5JER View Post
The question is what have others found in their own experiences?
Quote:
Originally Posted by sixshooter View Post
It depends on your horsepower level and the particular track.
The answer is right there. No one size fits all.
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Old 12-13-2014, 12:35 PM   #611
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The answer is right there. No one size fits all.
Except for Spanx. I'm pretty sure Spanx fits everyone.
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Old 12-13-2014, 12:46 PM   #612
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The answer is almost never so simple as you hope it to be, and the question is a bit too narrow-focused.

In terms of absolutes, the wing can generate more downforce than the spoiler (yes referring to the net effect of each as creating downforce for simplicity's sake). But back to back comparisons are few because the recipe for making the most of each differs. The real magic to increasing downforce on one end of the car is that you're then open to increase the downforce on the other end of the car to keep the car balanced and have an overall faster car.

Generally, a front aero set up that pairs well with a spoiler will be insufficient for most wings, unless we're talking about spoiler vs. GTC-200 with stock endplates and at standard height, which I've seen pair decently with roughly the same front aero as a SuperMiata has, which run rear spoilers.

Regarding balance, most miatas that are not anemic (140whp and up) can translate the benefits of more rear downforce into lowered lap times, even if the balance is less than ideal, and this is particularly true as power increases. Plenty of guys have experienced bolting a wing onto an otherwise un-aero'd car, pushed wildly all around the track, and still saw their lap times drop.

In my own personal experience on my car, I ran a very aggressive spoiler with a modest splitter and nose with dive planes for a couple seasons long ago. When I changed up to a wing, I redesigned the nose and splitter to compensate, and dropped several seconds the next time I returned to a track I had ran previously. But these anecdotes are always flawed as undoubtedly there were other areas of the car that were improved in the same time, and even the driver is not completely consistent

-Ryan
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Old 12-13-2014, 01:41 PM   #613
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I totally understand your point that pure comparison data is hard to come by because conditions are never the same unless you go to considerable effort to make it so. But some people do that.

Here's a hypothetical of what I was hoping for:

"Running the long course at LimeWillow I was doing 1:28s before aero, 1:27's with front and rear spoilers, and am currently down to 1:25's with a splitter/wing combo. No other significant changes during the aero upgrades."

He is not me, his car is not mine and it's a different part of the country. So clearly his experiences are only of general interest. And of course I made it up, so no one take it seriously. But it's the type of info I was interested in. If you were to get a few responses, you might define the trend. I figure that's unlikely, but you never know if you don't ask.
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Old 12-13-2014, 02:25 PM   #614
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So, the answer is a spoiler is faster.

And a wing is faster.

And both are faster than none at all. Unless they aren't.


Big wing or spoiler + low power + fast track with few sweepers = slower
A lot of F1 tracks are like that^. A COT wing is much lower drag than some other wings but also offers less downforce as a compromise. At some tracks certain cars will be faster with it than a spoiler car and on others the spoiler car will have better times.
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Old 12-13-2014, 06:00 PM   #615
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This is a stupid question if your rules allow a wing you run a wing because not only is it possible to make more downforce with the wing its also going to have a better lift to drag ratio. On top of that the endplates of the wing give you additional stability effects which the spoiler doesnt generate. If your rules allow both you can add a spoiler under the wing at a very low angle which will actually generate a bit of lift but noticeably reduce your drag.
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Old 12-15-2014, 06:33 PM   #616
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MX5JER, this is the thread you are looking for:

Post your DIY aero pics
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Old 12-16-2014, 11:12 AM   #617
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Quote:
Originally Posted by MX5JER View Post
No, you just don't understand the question. The answer is not math. Because the question wasn't what will work for me. The question is what have others found in their own experiences? Which may or may not apply to my situation. Now some will take the position that they did the work and cost and choose to keep the info to themselves. Go pay to find your own answers. Totally justifiable. But others don't tend to think that way.
if you double your speed, drag increases 4 times, so..

If you have a spoiler, lower speed more downforce, and some drag, but at speed it makes tons of drag at high speed so will kill your top end

A wing, will not make much downforce at low speed, and when at speed will give a lot more downforce, but due to its shape will not make near as much drag as the spoiler..

so you might have a track that has real technical section but then a high speed section.. it is at this point that you have to figure what works for *your* car, there is no one size fits all

It is at this point where it does take math.. you might use a spoiler and gain 4 sec in the twisty bits, but then lose 3 sec in the high speed due to drag

Then you put on a wing and you lose 3 sec in the twistys, but gain 4 in the high speed section

So then you find out that maybe they are both making the same lap times.. but say you as a driver are more comfortable with the spoiler in the twistys because the car felt planted.. it will then be physiological to make the driver more comfortable.

Hell, even if one set up has an overall slightly worse time, but you are consistsnt vs the car being on edge and about to spin out if you twitch the wrong way..

Maybe the car felt good with the wing, it all comes down to how you the driver feels about it. At this point it just comes down to your driving style and the car and then use math to figure the pros and cons for each
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Old 12-16-2014, 03:18 PM   #618
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Quote:
Originally Posted by mx5autoxer View Post
MX5JER, this is the thread you are looking for:

Post your DIY aero pics
Yes, that is a good thread for my purposes, thanks. Results/improvement is generalized instead of actual lap times, but that's probably for the best. Everybody always says to make one change at a time and evaluate it, but we seldom do it. So dependable data is hard to come by.

The reason I'm looking for quantitative results is to help decide how much money to throw at aero. Spoilers are much cheaper than wings and will allow money to be spent on better tires and suspension. I don't think I have the talent for a DIY high tech wing system, so if I go that way everything else on the car is going to have to wait a year.
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Old 12-16-2014, 03:23 PM   #619
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$/gains a cheap wing beats the hell out of a decent spoiler. You can get yourself into a cheap wing setup for a few hundred dollars for an APR GTC knockoff. Expect to spend quite a while and at least $150 for a spoiler thats going to do anything worthwhile and not look like a complete piece of redneck crap, and still be slower than the cheap wing setup.
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Old 12-17-2014, 08:17 AM   #620
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Originally Posted by Leafy View Post
$/gains a cheap wing beats the hell out of a decent spoiler. You can get yourself into a cheap wing setup for a few hundred dollars for an APR GTC knockoff. Expect to spend quite a while and at least $150 for a spoiler that's going to do anything worthwhile and not look like a complete piece of redneck crap, and still be slower than the cheap wing setup.
I think this would depend on the use of your car. I notice that most of the lower speed autocross guys just make a really large spoiler, where as most of the track guys build a wing. Coming from an autocross perspective I won't really reach speeds over 70 mph in our region, so a wing will need an aggressive AoA to achieve any sufficient down-force, where as a spoiler would achieve a similar result with less cost. I agree that spoilers are not as aesthetically pleasing...

But they don't always look bad.

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