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

[Golden-Arm]

they werent there to allow for tire clearance. the tires would be shredded on the edges, or grated on the screens. they did have screens, as items would be picked up and fired through the holes, had they not been screened. there's no reason to screen them, other than that. if you look at the tire on a race car, and collapsed the suspension on it, the tire isnt going to fit inside the hole anyways. i believe the tire story was just some BS created by chrysler, to hide the fact they were getting downforce from allowing the wheelwells to vent. air pressure builds under the car, and the front wheelwells are no exception. it is a simple tool, to aid in downforce, nothing more really. .02 cents 

[FJ5WING]

Did the race cars have the screen in the fenders under the scoops? I thought it was for additional tire clearence when the cars bottomed out in the corners due to the additional downforce?  

No screans on the race cars.   The street birds were not even cut out.

did I give the impression I was referring to Superbirds? I thought we were discussing Daytonas?

The thread started out,  "What is the purpose of the scoops?"   Birds have them too..

youre absolutly right  ..........for some reason I went right to the Daytonas.

[stripedelete]

I'm certainly no expert on wing cars and hiding a competitive advantage sounds very plausible,,,, in 1969 - 1970.  But "it ain't the launch codes" so why not come clean a decade or two later?  

[C5X DAYTONA]

they werent there to allow for tire clearance. the tires would be shredded on the edges, or grated on the screens. they did have screens, as items would be picked up and fired through the holes, had they not been screened. there's no reason to screen them, other than that. if you look at the tire on a race car, and collapsed the suspension on it, the tire isnt going to fit inside the hole anyways. i believe the tire story was just some BS created by chrysler, to hide the fact they were getting downforce from allowing the wheelwells to vent. air pressure builds under the car, and the front wheelwells are no exception. it is a simple tool, to aid in downforce, nothing more really. .02 cents  

Hey Thomas    No screens on the race cars.  Lets get that straight.    Tire is spinning in a forward motion.  Objects do hit the vent.  If that were the case, they would make them run mud flaps too.    The whole tire doesn't need to stick through the fender.  It was just rubbing the fender top in a small patch.   The aero aid was a benni..        

[hemi68charger]

Ok, short of reading every peice of literature ever written, where in the link does it explain the "reason"? I see plenty of "what if's" and the fact the Chrysler really never said conclusively why? But, everything points to tire clearance issues, thus reducing the potential for tire rubbing at high speeds and load. The race cars had bigger holes, not the small ones like the street versions, according to what I read................ Maybe we can get Tim to pull one of his scoops off #71 and check it out..... 

[pettybird]

conspiracy theories aside tire clearance is the only reason according to George Wallace or Larry Rathgeib.  I've heard the story more than once from them, and even under pretty intense grilling they stick to the clearance story.  If it was something else, why would they keep it a secret now?

side note:  GWB knocked down the twin towers, and if you play a $20 bill backward on a turntable it gives instructions for the Masonic handshake.

[Aero426]

Regardless of the end result of the scoops, the ORIGINAL problem encountered was on the '68 1/2 Charger race car.    They did have a legitimate tire rub problem on the right front of that car.    It was real.  That was where the idea that they MIGHT need the scoops came from.   Read the two excerpts posted here.

[Aero426]

Paragraph continued...   Note the creation of a blister on top of the fender and cutting away part of the hood.   This 68 1/2 car was extremely low.  

This piece of the story is fact, not some conspiracy theory.  

[xs29j8Bullitt]

But, everything points to tire clearance issues

conspiracy theories aside tire clearance is the only reason according to George Wallace or Larry Rathgeib.

Other than the recollections of these two gentlemen (admittedly important), what other evidence is there for tire clearance being the reason for fender scoops?  Tire clearance can be obtained with far less disturbance to the contour.  If you fit the outboard edge of a tire at a "best fit" into the larger race opening, it might protrude 1/2 before contacting the sharp un-radiused edges of the opening, so why the tall scoop... and no radii, especially on the forward edge of the opening?

Superbird brochure:

[xs29j8Bullitt]

Stuart is gonna like the "telestrator"...

[C5X DAYTONA]

Ok, short of reading every peice of literature ever written, where in the link does it explain the "reason"? I see plenty of "what if's" and the fact the Chrysler really never said conclusively why? But, everything points to tire clearance issues, thus reducing the potential for tire rubbing at high speeds and load. The race cars had bigger holes, not the small ones like the street versions, according to what I read................ Maybe we can get Tim to pull one of his scoops off #71 and check it out.....  

Here is my "reason for believing."  This comes from George Wallace 2004 as we are driving in my Daytona to Talladega.     George ask me while he pointing at the right fender vent.  Do you know why that is there?   I said,  yes, tire clearance.   George's reply was good..   George pointed at the left vent and said,  Do you know why that is there?  I said, clearance.  He said, no.  It would look dumb with one.   Then he said,  the Ford guys thought it was a vent.      But leave it to Doug to put the final nail on the coffin...     Here is Mr. Wallace and I that very day.    Awesome guy.

[xs29j8Bullitt]

Ok, short of reading every peice of literature ever written, where in the link does it explain the "reason"? I see plenty of "what if's" and the fact the Chrysler really never said conclusively why? But, everything points to tire clearance issues, thus reducing the potential for tire rubbing at high speeds and load. The race cars had bigger holes, not the small ones like the street versions, according to what I read................ Maybe we can get Tim to pull one of his scoops off #71 and check it out.....  

Here is my "reason for believing."  This comes from George Wallace 2004 as we are driving in my Daytona to Talladega.     George ask me while he pointing at the right fender vent.  Do you know why that is there?   I said,  yes, tire clearance.   George's reply was good..   George pointed at the left vent and said,  Do you know why that is there?  I said, clearance.  He said, no.  It would look dumb with one.   Then he said,  the Ford guys thought it was a vent.      But leave it to Doug to put the final nail on the coffin...     Here is Mr. Wallace and I that very day.    Awesome guy.

I understand your feeling Sean, but not knowing either gentleman, my approach is purely analytical.  The low speed and trans-sonic aerodynamics courses that I took to obtain my BS Aerospace Engineering degree make it clear to me that it did function as an air extractor, whatever the original design intent was.  My 30+ year Aerospace Engineering experience, including designing three air extractors on aircraft, makes it difficult to see how it effectively functioned to significantly increase tire clearance.

We can disagree while understanding each other's reasoning...

[Daytona Guy]

My understanding is tire clearance, simple................

If you look at the test mule this is clearly not the purpose of the scoops. I'm on an iPad so I can't post a pic - if someone has the pic of the mule post it.

Dane

[Daytona Guy]

Did the race cars have the screen in the fenders under the scoops? I thought it was for additional tire clearence when the cars bottomed out in the corners due to the additional downforce?  

They bottom out on the frame so the tire can't reach the top of the fender.

[C5X DAYTONA]

Ok, short of reading every peice of literature ever written, where in the link does it explain the "reason"? I see plenty of "what if's" and the fact the Chrysler really never said conclusively why? But, everything points to tire clearance issues, thus reducing the potential for tire rubbing at high speeds and load. The race cars had bigger holes, not the small ones like the street versions, according to what I read................ Maybe we can get Tim to pull one of his scoops off #71 and check it out.....  

Here is my "reason for believing."  This comes from George Wallace 2004 as we are driving in my Daytona to Talladega.     George ask me while he pointing at the right fender vent.  Do you know why that is there?   I said,  yes, tire clearance.   George's reply was good..   George pointed at the left vent and said,  Do you know why that is there?  I said, clearance.  He said, no.  It would look dumb with one.   Then he said,  the Ford guys thought it was a vent.      But leave it to Doug to put the final nail on the coffin...     Here is Mr. Wallace and I that very day.    Awesome guy.

I understand your feeling Sean, but not knowing either gentleman, my approach is purely analytical.  The low speed and trans-sonic aerodynamics courses that I took to obtain my BS Aerospace Engineering degree make it clear to me that it did function as an air extractor, whatever the original design intent was.  My 30+ year Aerospace Engineering experience, including designing three air extractors on aircraft, makes it difficult to see how it effectively functioned to significantly increase tire clearance.

We can disagree while understanding each other's reasoning...

   You got it.  It did function as a air extractor.  Totally.  I just think it being left open as a vent was an added benefit.  The original intent was to stop the tire from rubbing on hard bumps at speed.  After Daytona in Feb of 70 I don't think tire rub was ever an issue due to the restrictor plate.  So after that.  Defiantly just a vent in my opinion.    They were having a problem on the right front with rub in 68 as per the note Doug posted.      In your defence,   If anyone has ever driven a Daytona in the rain knows how much air and water comes out of those (things.)   Also, Larry Rathgeb was staffed with former aerospace engineers like Bob Marcell and John Pointer.

[C5X DAYTONA]

Did the race cars have the screen in the fenders under the scoops? I thought it was for additional tire clearence when the cars bottomed out in the corners due to the additional downforce?  

They bottom out on the frame so the tire can't reach the top of the fender.

You don't ever want to bottom out in a race car at speed on hard bumps. That is a big fat never too.   That is one good way to break spindles..

[Daytona Guy]

Regardless of the end result of the scoops, the ORIGINAL problem encountered was on the '68 1/2 Charger race car.    They did have a legitimate tire rub problem on the right front of that car.    It was real.  That was where the idea that they MIGHT need the scoops came from.   Read the two excerpts posted here.

Notice it hit the hood too - this is corrected in the suspension - not the scoop.

[C5X DAYTONA]

Well the HORSE(s) said,  Tire clearance.....     

[C5X DAYTONA]

Regardless of the end result of the scoops, the ORIGINAL problem encountered was on the '68 1/2 Charger race car.    They did have a legitimate tire rub problem on the right front of that car.    It was real.  That was where the idea that they MIGHT need the scoops came from.   Read the two excerpts posted here.

Notice it hit the hood too - this is corrected in the suspension - not the scoop.

Yes they did for the 68.  They could not modify the fender top.    Then came the Daytona with WAY WAY more downforce..   They were able to modify the fender top if the street car had it.    

[xs29j8Bullitt]

F Series Charger Wind Tunnel Test Report...

[hemi68charger]

Ok, short of reading every peice of literature ever written, where in the link does it explain the "reason"? I see plenty of "what if's" and the fact the Chrysler really never said conclusively why? But, everything points to tire clearance issues, thus reducing the potential for tire rubbing at high speeds and load. The race cars had bigger holes, not the small ones like the street versions, according to what I read................ Maybe we can get Tim to pull one of his scoops off #71 and check it out.....  

Here is my "reason for believing."  This comes from George Wallace 2004 as we are driving in my Daytona to Talladega.     George ask me while he pointing at the right fender vent.  Do you know why that is there?   I said,  yes, tire clearance.   George's reply was good..   George pointed at the left vent and said,  Do you know why that is there?  I said, clearance.  He said, no.  It would look dumb with one.   Then he said,  the Ford guys thought it was a vent.      But leave it to Doug to put the final nail on the coffin...    Here is Mr. Wallace and I that very day.    Awesome guy.

Yeap, George is an awesome guy. Had the privilege of chatting with him on pit row back in '04 at Talladega. What's mentioned here comes straight from the horses mouth and IS the only LOGICAL explanation. Tire clearance, tire clearance, tire clearance....................... That's my final answer.......  Next........  

I firmly believe the 'Birds don't have the holes cut out of the fenders just because...... they could get away without the mod as long as the scoop was there. Additional mod's equal additional money....

[pettybird]

but not knowing either gentleman, my approach is purely analytical. 

It's a shame you haven't met them.  They're sharp as tacks and remember the program vividly.

[Aero426]

The #5 Bobby Unser Superbird which is described by Terry Nichels as "the biggest cheater of them all" had no fender scoops whatsoever.  

[hemi68charger]

but not knowing either gentleman, my approach is purely analytical. 

It's a shame you haven't met them.  They're sharp as tacks and remember the program vividly.

  Mr. Wallace had so much influence in the Hemi, TA/AAR program, NASCAR; you name it.........

[nascarxx29]

 Air extractors make somesense as you see similar ones and same location except for the scoops.On high end european 200mph cars there fenders are louvred...I believe to reduce lift and air pressure under the car .The tire clearance reason has merit to.I read and heard somewhere before that nascar wingcars crew chiefs had plastic spacers under the torsion bar adjustment bolt.And after a few laps these spacers would crush down lowering the car.As they would check car height prerace and not post race.Wouldnt the fenders scoops just being there contribute to that advantage