Do "real" Daytona fenders have that little brace?

[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.