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