Sooooo... What was the purpose of fender scoops...? ***VOTE in added Poll***

[xs29j8Bullitt]

Tell me a bedtime story about the fender scoops Uncle Doug...

A long time ago in a galaxy far far away, Greg Kwiatkowski brought the original Daytona drag studies (the one posted above with the 3% drag statement) to John Pointer one day.   Pointer looked and admitted it was in his own writing.  He asked, "Where did you get THAT?" (as if Greg stumbled upon a secret document) Greg told him it was from Larry Rathgeb's files. When Greg pointed it out that the 'exhausters' helped with a 3% drag reduction, Pointer smiled slightly, winked and stated, "Those were the numbers we got."   Now, this was before the car hit the track!  Also, when the car finally hit Chelsea, being a 4.77 mile track was easier on the car in the corners than Daytona, for example.  Greg says, "So, right there tells me the 3% drag reduction was the primary goal, and any perceived benefit for tire clearance was secondary at best."    

Greg continues "That info, written by John Pointer prior to the car turning a race lap, is the smoking gun, as we say.  The fact that HE WROTE IT, "exhausters" are a 3% drag reduction, it came from wind tunnel studies as opposed to track information and that it was part of the recommended "Daytona" package tell me that  the reason for the scoops is DRAG REDUCTION.     This shouldn't be so hard to believe when it is original vintage documentation, and the writer of it confirmed it."    

Greg says "I give the Daytona team credit for keeping quiet all these years and sticking to their story! I especially like the old story John still tells that he made sure the scoops "did nothing"!     What else could they say??"

Thanks for the pics AND  bedtime story Uncle Doug!    

[Aero426]

And they all lived happily ever after. 

[xs29j8Bullitt]

 ... Wheres that chirping cricket animated gif....?   

[Daytona Guy]

  "Louvers" on top of the fender would not get the desired effect. The shape of the fender scoop creates a vacuum at the back opening as air flows over it at 190 mph; this helps to draw air out (not in) of the engine bay. Air flowing in through the front has only two places to exit, out the bottom of the engine bay (that creates instability), or help draw it out through the fender scoops. Why would they call it "exhausters"? Because that is what they do

PS, if it sucked air in - it would create drag, therefore if this was for tire clearance they would have just made a bulge with no opening.



Dane

[C5X DAYTONA]

Rathgeb, Pointer, Romberg or  Wallace.     You can chime in anytime now..     You knew the tire was going to hit before you drew the car Mr. Pointer.       

[C5X DAYTONA]

This I got from XX29.    Isn't this the original sketch?  No vents.    Why would of John left them off unless?   

[WINGIN IT]

Forget Mythbusters.   For $800 you can take your car to Aerodyn in Charlotte and run it in the tunnel.   You can determine what Romberg said that air goes IN to the scoops, not out.    Of course Troy you will need to cut open your scoops to race spec so the test is relevant.   
Because of the 36 degree banking, Bristol has tire loads much like Daytona and Talladega.
[/quote]

Because it would be cool to watch it on the tube perhaps, and have it publically published??


Even after your bedtime story,  I see posts AIR goes OUT, no AIR goes IN.... PROVE IT !

[Mopurr]

so, is this going to come down to a show me and then only believable......start a chip in to get the funds, pick a car and go to the tunnel and if you can get some of the old engineers there even better.

Sounds like a good meet activity.......lol

[hemi68charger]

so, is this going to come down to a show me and then only believable......start a chip in to get the funds, pick a car and go to the tunnel and if you can get some of the old engineers there even better.

Sounds like a good meet activity.......lol

No doubt................... It's curved like a tire, placed over the tire, centered over tire.............. Smells like a tire is the common denominator.. 

[maxwellwedge]

And they all lived happily ever after. 

+1

[C5X DAYTONA]

We also have to get that tire spining at 220+mph and right up to the fender top in the wind tunnel.           

[hemi68charger]

We also have to get that tire spining at 220+mph and right up to the fender top in the wind tunnel.          

Agreed, wind tunnel testing isn't a true test persay......

Back to our regularly scheduled programming.............................   Just drive & admire 'em................

[maxwellwedge]

We also have to get that tire spining at 220+mph and right up to the fender top in the wind tunnel.          

Do the Nascar boys do that now - spin up the wheels while in the tunnel?

I would think the air is looking at nothing more than the EPA (Effective Projected Area) of the tire. I don't think it cares too much if it is moving or not....unless the tire has paddles or the wheel has some kind of turbo effect built into it.

[maxwellwedge]

And.....

Bill Sr. let Chrysler put the scoops on if they let the King go to Ford.......

[Aero426]

so, is this going to come down to a show me and then only believable......start a chip in to get the funds, pick a car and go to the tunnel and if you can get some of the old engineers there even better.

Sounds like a good meet activity.......lol

I am actively seeking sponsorship for such an endeavor.     

[Aero426]

We also have to get that tire spining at 220+mph and right up to the fender top in the wind tunnel.          

Do the Nascar boys do that now - spin up the wheels while in the tunnel?

I would think the air is looking at nothing more than the EPA (Effective Projected Area) of the tire. I don't think it cares too much if it is moving or not....unless the tire has paddles or the wheel has some kind of turbo effect built into it.

The main Aerodyn tunnel has the capability to spin tires to simulate a rolling road and runs to 135 mph    For their A2 tunnel (which is where Gary and Pam tested the K & K), the wheels are stationary.   A2 is the cost effective tunnel to test in.   It tests between 30 and 85 mph, but they are able to calculate the aero forces at race speeds.

http://www.a2wt.com/

[xs29j8Bullitt]

No doubt................... It's curved like a tire <Really?!?  >, placed over the tire, centered over tire <both placed and centered, Huh?>.............. Smells like a tire < > is the common denominator.. 

Basics:  http://www.gmecca.com/byorc/dtipsaerodynamics.html

The fender scoops are "scuppers", aka air extractors, aka air exhausters, aka ...

Used on other cars: http://www.transamworld.com/ta-features.php#ffae

http://www.eng-tips.com/viewthread.cfm?qid=61524

To understand how it works, Google "Bernoulli Effect"...  basically as air is accelerated over the scoop, the air pressure is reduced locally...  same effect which gives an airplane wing lift... notice the airfoil shape is upside down on the rear wing spoiler horizontal bar...

[xs29j8Bullitt]

so, is this going to come down to a show me and then only believable......start a chip in to get the funds, pick a car and go to the tunnel and if you can get some of the old engineers there even better.

Sounds like a good meet activity.......lol

I am actively seeking sponsorship for such an endeavor.     

I'll chip in $100...

[Mopurr]

so, is this going to come down to a show me and then only believable......start a chip in to get the funds, pick a car and go to the tunnel and if you can get some of the old engineers there even better.

Sounds like a good meet activity.......lol

I am actively seeking sponsorship for such an endeavor.     

I'll chip in $100...

And here I thought 40 crazy Aero people @ $20 a piece and we already have a $100 offer  your sponsorship could happen ...lol

wonder if 40 or 50 people can get into the room where the data willl be coming into?

[41husk]

  I guess you will have to agree to disagree

[xs29j8Bullitt]

As for original intent...

In my opinion, air extraction to reduce front end lift without the increased drag of a larger nose spoiler...

The use of a "reverse" NACA scoop appears to have been the first attempt.  Look at the side-by-side comparison below.  Not a good idea, slow acceleration of airflow has minimum effect on pressure reduction.  Use of a standard exit ramp, or a modified exit ramp will give better results.

[WINGIN IT]

so, is this going to come down to a show me and then only believable......start a chip in to get the funds, pick a car and go to the tunnel and if you can get some of the old engineers there even better.

Sounds like a good meet activity.......lol

That's why I said let Mythbusters have at it- at THEIR cost. I'm sure with the resources they have they could come up with a viable plan.

Although a good meet activity sounds like a great idea as well. 

[xs29j8Bullitt]

so, is this going to come down to a show me and then only believable......start a chip in to get the funds, pick a car and go to the tunnel and if you can get some of the old engineers there even better.

Sounds like a good meet activity.......lol

I am actively seeking sponsorship for such an endeavor.     

I'll chip in $100...

And here I thought 40 crazy Aero people @ $20 a piece and we already have a $100 offer  your sponsorship could happen ...lol

wonder if 40 or 50 people can get into the room where the data willl be coming into?

I am 5x crazy?!?....      Maybe I should reduce my sponsorship to my standard 3x crazy... $60  

[xs29j8Bullitt]

so, is this going to come down to a show me and then only believable......start a chip in to get the funds, pick a car and go to the tunnel and if you can get some of the old engineers there even better.

Sounds like a good meet activity.......lol

That's why I said let Mythbusters have at it- at THEIR cost. I'm sure with the resources they have they could come up with a viable plan.

Although a good meet activity sounds like a great idea as well. 

Or the History Detectives show... 

[Aero426]

I am 5x crazy?!?....      Maybe I should reduce my sponsorship to my standard 3x crazy... $60  

I am guessing you are not the only one 5x crazy to want to know the answer.