Do "real" Daytona fenders have that little brace?

[Daytona R/T SE]

The brace that goes from the top of the wheel opening and extends to where the fender bolts on.     Roughly in the area where the fender scoop and screen goes.

[hemigeno]

 

[moparstuart]

that would be a YES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Daytona R/T SE]

Well, There it is!!! Proof positive! Thanks, Geno ! (again )

[hemigeno]

Well, There it is!!! Proof positive! Thanks, Geno ! (again )

Anytime!   

[BigBlockSam]

good pic Gene . that went into my file . thanks

[BROCK]

Thankyou for the pic Gene!  This should once & for all blow the old magazene reasoning for the scoop completely
out of the water.  Essentially the magazenes were saying that the fender scoops were there for homologation
purposes to gain tire clearance on the NASCAR version.  Nevermind the brace & the hole:  the scoop is narrower
than the tires.  Air extraction is a real benefit - but what do magazene types know

[hemigeno]

Thankyou for the pic Gene!  This should once & for all blow the old magazene reasoning for the scoop completely
out of the water.  Essentially the magazenes were saying that the fender scoops were there for homologation
purposes to gain tire clearance on the NASCAR version.  Nevermind the brace & the hole:  the scoop is narrower
than the tires.  Air extraction is a real benefit - but what do magazene types know

Grab a cold drink and read this (from aerowarriors.com):

The Scoop on Scoops

In my book you'd have to have a real snootfull of official Chrysler-brand KoolAid to buy that whole notion of tire clearance.   

[BROCK]

Thankyou for the pic Gene!  This should once & for all blow the old magazene reasoning for the scoop completely
out of the water.  Essentially the magazenes were saying that the fender scoops were there for homologation
purposes to gain tire clearance on the NASCAR version.  Nevermind the brace & the hole:  the scoop is narrower
than the tires.  Air extraction is a real benefit - but what do magazene types know

Grab a cold drink and read this (from aerowarriors.com):

The Scoop on Scoops

In my book you'd have to have a real snootfull of official Chrysler-brand KoolAid to buy that whole notion of tire clearance.   

I took your advice & grabbed a cold beverage, got comfortable & now vote it book of the year

[nascarxx29]

I believe my daytona fender also had that brace.And found some more related info on a daytona fender
#2. This is a new replacement fender for a 1970 Charger. The antenna hole was crudely cut out. Note the lack of the Daytona-only tab as is pointed out in the first photo. Also notice the clip is on this fender for mounting the splash shield

http://wwnboa.org/daytdetpt2.htm

[3--Daytona]

   All I can add to this "old" mystery is this,,,At the last Talledega meet, in a personel converstion with Larry Rathgeb, standing in front of my green Daytona, he said "they were for tire clearence on super speedway's and, I PUT THEM THERE,  end of story,,,,,,,,   3-daytona

[xs29j8Bullitt]

In my book you'd have to have a real snootfull of official Chrysler-brand KoolAid to buy that whole notion of tire clearance.   

I agree TOTALLY!  I have refused to believe the tire clearance story for over 35 years, and will never believe it...

Regardless of what Larry Rathgeb may recall after all these years, there are far too many clear indications he is wrong.  I have worked as an Engineer for 30 years, and have seen dozens of cases of faulty memory in co-workers... even experienced it myself.

Consider some of the evidence:

(1) The tire size vs opening size issue mentioned earlier... even if you assume it is only for the outside edge scrubbing, the gain would be minimal and having a smooth rub surface replaced by a sheetmetal edge would be counter-productive.
(2) If for SuperSpeedway tire clearance, why put them on the street cars at all... the street tire doesn't get anywhere near the top of the fender.
(3) When the problem with debris being ejected through the scoops was realized, why cover the opening with a porous screen?  No increased clearance (less actually due to the screen thickness), but air flow is still maintained...
(4) In addition to the document mentioned on the AeroWarriors website, one of the wind tunnel reports that I have a copy of mentions fender mounted "air exhausters" or "air extractors" in the narration.
(5) The two page black & white Superbird advertisement with the labeled features of the Superbird refers to the scoops as "air extractors" or "air exhausters".

Just my 

XS

[wingfan]

Doug Schellinger's explanation convinced me that the fender holes were for tire clearance as the engineers said.   I searched but couldn't find the thread on the DSAC fourm and don't remember the technical details.  The race car was lowered so they thought the hole was necessary given the amount of down force.  The hole doesn't have to be big enough for whole tire, just big enough for the section that would rub.   Remember the race Daytona was nothing like the street model except in looks.   Chrysler was afraid it wouldn't be homologated if the street car didn't have the fender holes.   It turned out they weren't required, so no holes in the Superbird fenders.   

[3--Daytona]

I dont disagree with anybodys opinion,,,,,,but one thing for certain, they make  the brand x  people talk.         3-daytona

[nascarxx29]

But there is this factory paperwork I have around here if a owner wanted for his street superbird fenders cut out like a daytona.You could have got it that way.

[hemigeno]

they make  the brand x  people talk.

A couple of points I've yet to hear an answer for from those who lean towards tire clearance:

>>  If the scoop is just for tire clearance, why was the rear edge of the scoop the tallest point?  It would have been much more aerodynamic to make it just a "hump" - with the tallest point in the middle where the tire would rub.

>>  Why put a hole on the backside of the scoop at all if it's just for tire clearance? 



I really wonder if Larry Rathgeb had any idea that people would be this interested in his work 40 years later...   

[Aero426]

they make  the brand x  people talk.

A couple of points I've yet to hear an answer for from those who lean towards tire clearance:

>>  If the scoop is just for tire clearance, why was the rear edge of the scoop the tallest point?  It would have been much more aerodynamic to make it just a "hump" - with the tallest point in the middle where the tire would rub.

>>  Why put a hole on the backside of the scoop at all if it's just for tire clearance? 



I really wonder if Larry Rathgeb had any idea that people would be this interested in his work 40 years later...   

The answer on why no fender hump is easy.  Tooling cost.   The plastic scoop was an easy option for a short run.   Other question then is, how large do you make that hump? 

The common sense answer on the dealer tech bulletin for the Bird scoop holes was that is was a CYA thing in case NASCAR called them on it.    It saved a cost and labor operation on the production side.

[hemigeno]

Doug,

They could have molded a fiberglass hump just as easy as they could have molded a fiberglass scoop.  That's what I had in mind when I asked the question, anyway.  I understand completely about sheet metal tooling costs - that would have been prohibitive I'm sure.

[Aero426]

Doug Schellinger's explanation convinced me that the fender holes were for tire clearance as the engineers said.   I searched but couldn't find the thread on the DSAC fourm and don't remember the technical details.  The race car was lowered so they thought the hole was necessary given the amount of down force.  The hole doesn't have to be big enough for whole tire, just big enough for the section that would rub.   Remember the race Daytona was nothing like the street model except in looks.   Chrysler was afraid it wouldn't be homologated if the street car didn't have the fender holes.   It turned out they weren't required, so no holes in the Superbird fenders.   

I can't find that thread either.  But in short, your mind has to reach back farther to 1968 with the Charger.  They DID have problems with tire clearance on the right front.   Maybe it was the way they had the cars raked.  If you think that the design of the Daytona was frozen in late Spring '69,  it's not a reach to accept the explanation that they scoops were put there in the event they needed them.    Once the car was homologated (accepted) they could not go back and change it.       

Here is a photo of Isaac's car at Atlanta in 1968.   Look how little room there is on top of the "tar".   Now imagine that it's the right front and you've got to have some suspension travel when you are loaded in the corner.    It's not hard to see why they felt they needed some insurance on the Daytona.    It does seem that the '68 cars were lower than the '69 and '70 cars on the track too.



There has not been one person on the engineering or race side who has said ANYTHING other than the clearance story.   These guys are not all talking to each other either.   If there's a reason to hide something 40 years after the fact, I don't know what it is.    Maybe there was some kind of aero gain.  But we won't know for sure unless we can get Romberg to put a wing  race car in the Aerodyn wind tunnel in NC. 

[hemigeno]

>>  Why put a hole on the backside of the scoop at all if it's just for tire clearance? 

The common sense answer on the dealer tech bulletin for the Bird scoop holes was that is was a CYA thing in case NASCAR called them on it.    It saved a cost and labor operation on the production side.

I'm not talking about the hole underneath the scoop - I'm talking about having the back area of the scoop open at all.  Similar question to the one before it.  Why not just have a hump with the highest point in the middle and tapering off to nothing at the front and rear of a molded fiberglass piece?  THAT would serve for tire clearance and would have no other purpose.

[hemigeno]

These scoops/exhausters/vents look like they serve a purpose and it ain't tire clearance...   

[Brock Samson]

dual purpose?.. 

[Aero426]

I'm not talking about the hole underneath the scoop - I'm talking about having the back area of the scoop open at all.  Similar question to the one before it.  Why not just have a hump with the highes point in the middle and tapering off to nothing at the front and rear of a molded fiberglass piece?  THAT would serve for tire clearance and would have no other purpose.

Good question.    I'm not sure if the current scoop was closed off if it would or would not present a drag problem.   A teardrop scoop would need to be quite a bit bigger.    My gut tells me that If the prediction scoop was left open and there was some net benefit, they felt so be it.    I believe if there was something other than the lock step story everyone has told, someone would have caved by now.

[Aero426]

I dont disagree with anybodys opinion,,,,,,but one thing for certain, they make  the brand x  people talk.         3-daytona

I think that was also part of the idea too.  If they did not help or hurt, they could draw attention away from something else.

[xs29j8Bullitt]

Look at the shape of these early scoops... consider the planform shape and how the aft edge is twice as high as the point over the tire centerline.

XS

[Aero426]

These scoops/exhausters/vents look like they serve a purpose and it ain't tire clearance...   

I don't disagree.  Those cars also have managed air being force fed to the brake rotors from the top of the nose. 

What's not clear is whether the wing car scoops served a secondary purpose, and exactly how much.    I recall the fender exhausters comment and a small drag reduction.  Again, it's not clear on whether that was proved out on a scale model or the real car.

[Aero426]

Good point.  This would be an excellent photo to show those guys and ask for an explanation.   

[hemigeno]

The document that aerowarriors.com points to as the best evidence for a purpose other than tire clearance is the one below from Greg Kwiatkowski's collection.  The interesting thing to me is that another setup tried was "bulged" fenders.  They may initially have been trying to solve an actual or anticipated tire clearance problem, but the scoops had a positive impact on drag of 4% over bulges in the fenders.  Also, the scoops on that photo Allen posted of the #99 [edit - #71] car did not extend all the way to the outer edge of the fender, where tire interference would be encountered first.

[Aero426]

The document that aerowarriors.com points to as the best evidence for a purpose other than tire clearance is the one below from Greg Kwiatkowski's collection.  The interesting thing to me is that another setup tried was "bulged" fenders.  They may initially have been trying to solve an actual or anticipated tire clearance problem, but the scoops had a positive impact on drag of 4% over bulges in the fenders.  Also, the scoops on that photo Allen posted of the #99 car did not extend all the way to the outer edge of the fender, where tire interference would be encountered first.

Yes, that's the document.   That is a 3/8 scale model test.  Were those numbers proven out full scale?  I don't believe there is a record of that.

Agree on Allen's photo of the #71.  

[xs29j8Bullitt]

If I recall correctly, the bulged fenders were shown in one of the pictures of the wind tunnel report.  I need to find the reports! 

Allen

[hemigeno]

Same scoops on this early picture of the "probe" car  (MAN am I glad they didn't call this car "Probe")...

[440mop]

Regarding the picture of the early scoops, if you were to be looking up at them from inside the fender they look very much like NACA ducts, which were specifically designed to draw air through them without creating drag.

[Aero426]

Regarding the picture of the early scoops, if you were to be looking up at them from inside the fender they look very much like NACA ducts, which were specifically designed to draw air through them without creating drag.

It is a lot like an upside-down NACA duct.  Then another question is, "Why didn't they just use a NACA duct?  Why did they make it wider?

[pettybird]

Here's some more compelling pictures for the tire clearance camp--these are the #71 car from the Talladega museum:









Here's the TSB on 'bird scoop cutouts








Here are pics of the #88 (recreation?  what's the story on this car again? 2x2?)  The people in red are important, and there's some guy in blue.  They jumped the ropes, poked their heads inside the car, opened the hood.  It was awesome.  Someone at the meet asked what they'd say if security came by.  Gary Rhomberg (I think--Doug?) said "we'll tell them we're the original owners."  Priceless.









Also a pic of Buddy Baker poking his head through the wing like the record run--possibly the best part of an incredible meet. 

[Aero426]

Charlie Glotzbach,  Buddy Baker and Larry "I put the scoops on the car" Rathgeb.    I'll take credit for asking Baker to re-create the photo with the board.    His comment was along the lines of, "I thought I was holding a tire or something".  Been a long time.

[Aero426]

George Wallace and Larry Rathgeb are confirming the intake manifold on the museum #88 is the 2 x 2 car. 

[Aero426]

If it hasn't been made clear, these two cars are the same.   They are also the illegal 2 x 2 Charger that Isaac drove at Daytona in July '68.

[C5X DAYTONA]

If it hasn't been made clear, these two cars are the same.  They are also the illegal 2 x 2 Charger that Isaac drove at Daytona in July '68.

Sorry to bring up an old thread.   Doug,   When I talked to Bob McCurry around 2005 I asked him about the #88 car in the Talladega museum to get his take on it.     He said  Talladega wanted the 200 MPH Daytona.  So they (Chrysler) took the mule and put Daytona sheet metal on it and sent it them.     Be awesome to see the clone #88 car in Talladega back to the mule. 

[odcics2]

I sent Tim Wellborn the photos of the mule at Chelsea many years ago. I asked John Pointer if he was on board to help built a 'new' nose and wing for it, since he did the originals... He was!

Best laid plans...

[wingcar]

I think once we find Amelia Earhart's plane we will finally know the complete story...until then, I have to go with what the Chrysler Engineers from back in the day have told us....................(just my two cents )

[odcics2]

I'll go with the hard data that John Pointer put together and the fact that he was VERY surprised to see it surface after all the years!   The "knowing wink" when asked about the 3% drag reduction for the scoops told it all...   

[C5X DAYTONA]

Great,  now 2 threads on the same thing..   But yes, the 3% came after the engineers told him to fix the fender top.   Pointer did an awesome job.  But after he was to informed to work on the clearance issue the engineers had before and saw it was going to come back.    Just ask the engineers...  Wait, we did.  Wallace's comment was,  we need the clearance.  It was up to Pointer to design it.  That was his expertise..   The Daytona is in fact Pointer's design.  But the engineers wanted that fender modified now that they could according to the Grand National Rules.   And Pointer fixed it..   There is no doubt that Pointer made it with an aero advantage.    But the engineers were first to point out that spot on the fender top that they saw on his aero packing per his first drawing.   

[C5X DAYTONA]

I sent Tim Wellborn the photos of the mule at Chelsea many years ago. I asked John Pointer if he was on board to help built a 'new' nose and wing for it, since he did the originals... He was!

Best laid plans...

That would of been awesome to have Pointer fix that car.   Hopefully some day soon it will be back to it's Mule configuration.  IMHO

[Daytona Guy]

The document that aerowarriors.com points to as the best evidence for a purpose other than tire clearance is the one below from Greg Kwiatkowski's collection.  The interesting thing to me is that another setup tried was "bulged" fenders.  They may initially have been trying to solve an actual or anticipated tire clearance problem, but the scoops had a positive impact on drag of 4% over bulges in the fenders.  Also, the scoops on that photo Allen posted of the #99 [edit - #71] car did not extend all the way to the outer edge of the fender, where tire interference would be encountered first.

Hemigeno,

When I read that report - I was under the impression that the bulging of the fenders was not referring to the top of the fender, but was referring to the top side of the inner fender for tire clearance as seen in that red Daytona fender (fender scoop) pic in the above post. That is what produced drag - but necessary for turning and the fact that the tires would rub on the "upper side" of the inner fender. Look how far out they bulge or flared the fenders on the side, it seems hard to believe that that tire would then travel and hit the middle of the top fender. If they turned the tire hard L or R (trying to correct a hard drift) and the tire traveled up that high – it could shred the tire. I don't think the geometry allowed for that. Just thinking out loud 

Dane

[Daytona Guy]

OK - it was for tire clearance - took at the tire marks on the underside of the fender scoop 

[Aero426]

OK - it was for tire clearance - took at the tire marks on the underside of the fender scoop  

That ain't real. 

[Aero426]

My recollection is that "bulged fenders" refers to the side of the fender, not the top.    Once they started racing, the fender modifications by teams evolved over time.    The first racing Daytonas in '69 had modest sheet metal modifications.   The later cars in 1970 had fenders drooped and flared by teams as much as they could get away with.      Compare the #6 Baker show car to the existing #71 Isaac car and you will see what I mean.  

[hemigeno]

The document that aerowarriors.com points to as the best evidence for a purpose other than tire clearance is the one below from Greg Kwiatkowski's collection.  The interesting thing to me is that another setup tried was "bulged" fenders.  They may initially have been trying to solve an actual or anticipated tire clearance problem, but the scoops had a positive impact on drag of 4% over bulges in the fenders.  Also, the scoops on that photo Allen posted of the #99 [edit - #71] car did not extend all the way to the outer edge of the fender, where tire interference would be encountered first.

Hemigeno,

When I read that report - I was under the impression that the bulging of the fenders was not referring to the top of the fender, but was referring to the top side of the inner fender for tire clearance as seen in that red Daytona fender (fender scoop) pic in the above post. That is what produced drag - but necessary for turning and the fact that the tires would rub on the "upper side" of the inner fender. Look how far out they bulge or flared the fenders on the side, it seems hard to believe that that tire would then travel and hit the middle of the top fender. If they turned the tire hard L or R (trying to correct a hard drift) and the tire traveled up that high – it could shred the tire. I don't think the geometry allowed for that. Just thinking out loud 

Dane

I am not sure exactly what the "bulge" inferred, to be honest.  Nice photoshop though...  

[odcics2]

To be clear, blunt nosed cars liked the "bulge" on the fender side. This allowed the air to re-attach somewhat to the car.
This was also a rake dependent thing, too!!   And depended on other things like if the grill was laid back. (think Petty 68 black top car)

On the Daytona (and 'Bird) that was not the case. They worked best with smooth areas right above the wheels on the front fenders.
As is the case, the teams still did what they wanted to do!!    Cotton's #6, for example, had a lip around the front wheel opening. Not good!  
The 'penalty" was only 1% more drag for extra tire clearance.

Note that both Chrysler Engineering vehicles, the red #71 mule and DC-93 (aka #88), did not have bulges on the fenders above the front tires.

[C5X DAYTONA]

IT DOENS'T MATTER WHAT ANYONE DID TO THE VENT.      This is about how it got there.    Note.. that the E-Series Charger 500 1/8 car has never been photographed with any hole above the front tire.   Ever.  Nor any real test results.  They never tested a full sized Daytona in a wind tunnel.  So if pointer got 3% out of it.  How did he do that?   As of yet, there is no proof on the 1/8 scale car having holes for extractors in the fender.     The 1/8 scale E-Series is still alive.   I hope to have it examined tomorrow.  I had the E-Series Charger 1/8 scale in my garage for a while.  And I never saw any holes above the tire.  It was the only 1/8 scale car tested to my knowledge or even built to my knowledge.

[C5X DAYTONA]

Winged Warrior Newsletter, August, 1977:
          "Probably the main question asked of John [Pointer] in the question and answer session again this year was what the purpose of the fender scoops [was]? John said it was found in the Charger 500 that in super speedway cornering the right front tire was rubbing up against the fender causing the terrible smelling smoke to enter the driver's compartment making it unpleasant to drive. So to get the extra one inch of tire clearance they needed for the right front tire they put the scoops on the car, and for no other reason

[C5X DAYTONA]

Winged Warrior/B-Body Review, September, 1996: (question to John Pointer)
"(Q) OK, if the Daytona racecar's fender scoop is for clearance, why doesn't the fender look as wide as the tire?

  (A) Tires are not straight up and down when turning. It was only the top outer edge of the turning tilted tire that rubbed so the scoop was enough to let it clear."

[C5X DAYTONA]

Supercars: The Story of the Dodge Charger Daytona and Plymouth SuperBird, by Frank Moriarty:

"Curiously, one aspect of the press preview seemed to cause endless fascination and speculation among the witnesses. Why did the wing car have rearward facing scoops on the fenders above the front wheels? To this day, articles and books about that era still come up with a bizarre array of explanations for the scoops, ranging from alleged aerodynamic benefits to engine heat ventilation. In reality, the purpose of the scoops is considerably less exotic.


At the NASCAR super speedways, front tire clearance in the wheel well was often a problem. The tires would be forced into contact with the fenders when the car passed through a high-banked turn at nearly 200 MPH. To solve that problem on the Daytona, Larry Rathgeb came up with an idea -- a backwards facing air scoop that would do nothing more than provide room to prevent the tire from coming in contact with the fenders.


          'I worked furiously on those things to make sure they didn't do anything aerodynamically,' John Pointer says. 'They were just there to provide an extra inch or two of tire clearance'.


          As Gary Romberg notes, 'There were myths around those things all the way to the racetrack for years! All during the time that the cars were on the race tracks, that was supposed to be one of the major tricks. And that was no more than tire clearance!'"

[C5X DAYTONA]

When I asked George Wallace about the vent that everyone says it was for air.  He says,  NO.  When engineering saw the drawing from Pointer, Engineering asked Pointer to make clearance there.   Wallace said,  what Pointer did with it was his job.   It was his expertise. 

[C5X DAYTONA]

Here is a shot of Wallace with the 1/8 scale E-Series Charger.   Awesome guy.

[odcics2]

Why would they test improvements on a scale model when they could do it on the full scale red mule at Chelsea and get actual results?

That could explain why there are no holes on the scale model.  Obviously we know that they tested the hell out of both the red and blue Engineering cars at Chelsea.

[C5X DAYTONA]

Why would they test improvements on a scale model when they could do it on the full scale red mule at Chelsea and get actual results?

That could explain why there are no holes on the scale model.  Obviously we know that they tested the hell out of both the red and blue Engineering cars at Chelsea.

It was way cheaper to modify and test the 3/8 (not 1/8 like I posted before) scale car when the effects are the same in the wind tunnel.    Also it was cheaper to rent the smaller wind tunnel in Kansas.  The Red Mule was a slow speed test car.     The Blue #88 was a high speed test car that got the final results from the 3/8 test car transferred to full scale.