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Joshua

New Miata Air Dam = 3pts?

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wlfpkrcn1
cookie.jpg

 

Mnnn cookie.....

 

 

 

[Now what starts with the letter C?

Cookie starts with C

Let's think of other things

That starts with C

Oh, who cares about the other things?]

 

C is for cookie, that's good enough for me

C is for cookie, that's good enough for me

C is for cookie, that's good enough for me

Oh, cookie, cookie, cookie starts with C

 

C is for cookie, that's good enough for me

C is for cookie, that's good enough for me

C is for cookie, that's good enough for me

Oh, cookie, cookie, cookie starts with C

 

[Hey you know what?

A round cookie with one bite out of it

Looks like a C

A round donut with one bite out of it

Also looks like a C

But it is not as good as a cookie

Oh and the moon sometimes looks like a C

But you can't eat that, so ... ]

 

C is for cookie, that's good enough for me, yeah!

C is for cookie, that's good enough for me

C is for cookie, that's good enough for me

Oh, cookie, cookie, cookie starts with C, yeah!

Cookie, cookie, cookie starts with C, oh boy!

Cookie, cookie, cookie starts with C!

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Cobra4B

Because of this thread I went to Subway for lunch and splurged on 3 cookies.

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bobzdar

If there is any doubt that that type of front air dam (or wing, whatever) produces quite a bit of downforce, here's a shot of a car with a similar front air dam at speed - note the downward deformation. I have the same setup on my car and that air dam is bolted to a stamped steel cross member, which to bow downward in that fashion would also have to bend the cross member (it's not that thick, but should give you an idea of the downforce created - based on that amount of bend I'd estimate 100-150lbs).

 

79fa10.1.jpg

 

Just an FYI for the discussion.

 

As an aside, would it be legal to reinforce a factory air dam so it doesn't bend like that? It'd actually cost you downforce but would hopefully prevent it from being damaged.

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wlfpkrcn1
Because of this thread I went to Subway for lunch and splurged on 3 cookies.

 

The easiest place to take weight out of a race car?......The driver

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Cobra4B
Because of this thread I went to Subway for lunch and splurged on 3 cookies.

 

The easiest place to take weight out of a race car?......The driver

So true... I remember reading a story about John Force's motivation to lose weight... basically he said something like, "We spend so much money in testing and R&D to make a part on the race car 1lb lighter, when I could afford to lose 50."

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TurboShortBus
Because of this thread I went to Subway for lunch and splurged on 3 cookies.

You nasty bastid...I feel bad for the poor schmuck who eats them...

 

Mark

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Cobra4B
Because of this thread I went to Subway for lunch and splurged on 3 cookies.

You nasty bastid...I feel bad for the poor schmuck who eats them...

 

Mark

Splurged /= splooged

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TurboShortBus
If there is any doubt that that type of front air dam (or wing, whatever) produces quite a bit of downforce, here's a shot of a car with a similar front air dam at speed - note the downward deformation. I have the same setup on my car and that air dam is bolted to a stamped steel cross member, which to bow downward in that fashion would also have to bend the cross member (it's not that thick, but should give you an idea of the downforce created - based on that amount of bend I'd estimate 100-150lbs).

In the case of that photo, I would say that the air is just pushing that air dam back, just as it would push the bumper back, as it is located in a high-pressure area.

 

Don't confuse production of downforce with reduction of lift; the latter is accomplished by most air dams, chin spoilers, splitters, etc. All they do is negate lift, but they don't typically produce significant amounts of downforce (so that the car would exert more of a force on the driving surface while at speed than it does while it is at rest).

 

Case in point: the Mustang FR500S. With the front splitter, it has 7.2 lbs of lift at 80 mph. At 120 mph, the downforce is a whopping 2.6 lbs. There is no data on the amount of front lift without the front splitter, though.

 

More info: http://www.fordracingparts.com/Mustang/fr500sownerinfo/Aero_Info_FR500S_v1.pdf

 

Mark

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bobzdar
If there is any doubt that that type of front air dam (or wing, whatever) produces quite a bit of downforce, here's a shot of a car with a similar front air dam at speed - note the downward deformation. I have the same setup on my car and that air dam is bolted to a stamped steel cross member, which to bow downward in that fashion would also have to bend the cross member (it's not that thick, but should give you an idea of the downforce created - based on that amount of bend I'd estimate 100-150lbs).

In the case of that photo, I would say that the air is just pushing that air dam back, just as it would push the bumper back, as it is located in a high-pressure area.

 

Don't confuse production of downforce with reduction of lift; the latter is accomplished by most air dams, chin spoilers, splitters, etc. All they do is negate lift, but they don't typically produce significant amounts of downforce (so that the car would exert more of a force on the driving surface while at speed than it does while it is at rest).

 

Case in point: the Mustang FR500S. With the front splitter, it has 7.2 lbs of lift at 80 mph. At 120 mph, the downforce is a whopping 2.6 lbs. There is no data on the amount of front lift without the front splitter, though.

 

More info: http://www.fordracingparts.com/Mustang/fr500sownerinfo/Aero_Info_FR500S_v1.pdf

 

Mark

 

You can see that the air dam is also bowed down significantly. If it were just being pushed back, it would flatten (ie the angle would increase) and not bow down to that degree. In stock form at rest, the top of the air dam is level with the ground with no bow. The reason I brought this up is that I have the same car sitting in my garage and know how that spoiler mounts. I do not know how it could bow a stamped steel cross member down 2-3 inches without exerting some downforce. At the time the car was introduced, Pontiac claimed 50lbs of downforce front and rear at highway speeds - but the front was helped by the fender air extractors as they would create a low pressure area inside the engine compartment. I have no idea what they considered highway speeds or how accurate that was, but the car above has no aero mods from stock other than a larger hood scoop and you can see how much it is bending the front air dam down. I don't know how fast the car is going in that picture, but it was capable of 170mph according to the builder (Herb Adams).

 

Just some food for thought on a car with a similar air dam.

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TurboShortBus

I'm not sure how 1970s technology is making more downforce than 21st century technology, but OK. Maybe Ford needs to hire some disco-era engineers (or Pontiac's marketing department...they need something to do these days).

 

While it is true that there may be some downforce on a given splitter or spoiler, there is no guarantee that it will translate into downforce as measured at the asphalt if it only reduces some of the lift.

 

In that photo, I'm more concerned that the high-pressure area under the front bumper (which is bending the air dam) is actually causing lift; I see the bumper itself as a high-mounted splitter. But, it may cause less lift than without the air dam.

 

As for the bending, any structural member that bends is not working as well or as efficiently as it should. Reinforcing it would help to increase its performance, not decrease. Have you ever seen a bridge sag, and thought, "Wow, look at how much weight it's holding?" Hell no...you ran for your life. How effective would a rear wing made out of cardboard be if it was allowed to deflect? Not very.

 

Mark

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Shawn M.

 

79fa10.1.jpg

 

Just an FYI for the discussion..

 

 

Is it creating any downforce at all or is it creating drag?

 

Discuss.

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bobzdar

I'm not sure where the bridge analogy comes from, but that's a straw man. Flexible wing elements are not new and have been banned in most racing series where aero is not spec, so a flexible structural member in that case can be desireable.

 

Anyway, I'm sure it creates quite a bit of drag. I still do not know why it would flex so far down in the center if it was creating no downforce. Whether it's enough to counteract all of the lift the nose generates, i don't know. I do know that they actually used a wind tunnel to develop the aero on the car and there were no discos involved. The disco influence was seen with all of the gold pinstriping and the big bird on the hood.

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949Racing

Direct from Greg as of yesterday: 6 points, not homologated

 

G.1. extend vertical reach of OEM fascia

G.2. add spoiler

 

G.4. is a gray area that could be argued either way at the event. No official points assessment on G.4. was made either way via email. General feeling by both Greg, myself and perhaps others here is that it might be difficult to prove that the integrated spats of the SPM dam constitute a canard/winglet in letter or spirit.

 

Not homologated means each competitor may submit theirs for approval if points confirmation is desired. This

forum post does not constitute approval or legality, just a reference.

 

Hopefully I have this right. Mods, feel free to edit my post if need be. I consider the issue closed.

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Greg G.
Direct from Greg as of yesterday: 6 points, not homologated

 

G.1. extend vertical reach of OEM fascia

G.2. add spoiler

 

G.4. is a gray area that could be argued either way at the event. No official points assessment on G.4. was made either way via email. General feeling by both Greg, myself and perhaps others here is that it might be difficult to prove that the integrated spats of the SPM dam constitute a canard/winglet in letter or spirit.

 

Not homologated means each competitor may submit theirs for approval if points confirmation is desired. This

forum post does not constitute approval or legality, just a reference.

 

Hopefully I have this right. Mods, feel free to edit my post if need be. I consider the issue closed.

Emilio's post above appears accurate.

 

We will post a Technical Bulletin with some clarification of what is an "air dam" (G.1) vs. a "front spoiler" (G.2). The wording is not ready to be published yet, but essentially it will have to do with air dams being vertical, such as the photos in the Markus_F post photos on page 4 of this thread. Splitters are horizontal, etc.

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Joshua

Thanks for the clarification. Too bad, it looks like a very nice part.

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