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

[xs29j8Bullitt]

On the fake #88, it's just the cut of the wheel opening, or that particular spot on the forward part of the wheel lip is pushed in a little bit.    The angle of the photo makes it look less concentric.  

OOPS...  The B&W pic of the fake #88 slipped by...    I was too busy looking at the wheel opening shape...     In the other pics, there does not seem to be much distance from the opening to the top of the fender though...  

[Aero426]

I was too busy looking at the wheel opening shape...     In the other pics, there does not seem to be much distance from the opening to the top of the fender though...  

If you referring to the fake #88, keep in mind it is the big fat cheater busted at the '68 Firecracker 400.  Because of the tricks played with the body shell, the bottom of the rocker panels are shaved at the front to make it all work.   Look how weird the front of the rockers look and the bottom of the front fender.    Things are going to fit differently on that car.   In any event, since the car was mocked up for display when it was donated, you can't read too much into it relative to other Daytonas.   I hear there is a period photo of that car raised, umm, a little higher.    

[Aero426]

Here's the fake 88 (68 1/2 race car) in its work clothes.    Note that it's now been raised up so high that you can slide the oil drain pan underneath without jacking the car up.   When they were caught at Daytona, they had to run the race this way.   

[Aero426]

At Daytona, this thing was slammed to the ground.   Now you can drive a lowered '64 Chevy underneath.

[Aero426]

By comparison, this is one of the other '68's but NOT the illegal x2 car which was more radical.   This is the starting point for why they felt they needed the fender scoop.  

[Aero426]

Another race fender showing the scoop opening.   This is from the #88.

[FJ5WING]

sure does look like the top of a tire would have clearence there.

if a lil hole lets some air out a biggun will let out more air!

[tan top]

this is a good thread   , lot of intresting ideas pictures   , love reading this kind  stuff  

, my    tire clearence !!  because of  what i read  many years ago , ! the scoops were purly there for an extra margin of tire clearence at speed going into a corner with loading on the right front suspension
, also sure it said !  ((((( it was made sure the scoops did not affect the aero ! or they were designed in a way that it would be minimal ))))))))))
was  searching through stuff , looking for where i had read this (was words from one of the guys on the daytona project )  came across this picture !!  thought i would post it as there are a couple of good pictures of  superbirds with out scoops  

[XS29LA47V21]

Another race fender showing the scoop opening.   This is from the #88.

I have not seen one loose before, that is very interesting to see.  thanks for sharing

[Daytona Guy]

this is a good thread   , lot of intresting ideas pictures   , love reading this kind  stuff  

, my    tire clearence !!  because of  what i read  many years ago , ! the scoops were purly there for an extra margin of tire clearence at speed going into a corner with loading on the right front suspension
, also sure it said !  ((((( it was made sure the scoops did not affect the aero ! or they were designed in a way that it would be mimimal ))))))))))
was  searching through stuff , looking for where i had read this (was words from one of the guys on the daytona project )  came across this picture !!  thought i would post it as there are a couple of good pictures of  superbirds with out scoops  

I would put money on that cone being glass   The same one they used on the white/Red wing car with the pin stipe headlight doors.

[A383Wing]

also looks like a Daytona...not a 'Bird

[HPP]

I haven't bothered to read all 8 pages, but, street cars or competition cars?

Street cars, purely asthetics.

Comp cars, they are aero aids. Airflow through the grill stacks up in the engine bay and creates lift. The scoops allow built up pressure in the nose to escape by being pulled out by the high speed, low pressure area above them. They are too narrow to provide any real tire clearance. Besides, the suspension would bottom out before the tire contacted the fender top.

We've all heard the story about tire clearence. It is a red herring. We all know none of the Chrysler engineers would ever suggest anything wasn't what it would seem, right? Kinda like plastic spacers put on the torsion bar adjusters to allow cars to meet ride height limits at the start of the race, but allow them to drop in height after a couple of bumps at speed. Or how about the imfamous trans am acid dip proposition. No, Chrysler's race engineers never "embelished" their statements at all.

[Highbanked Hauler]

 Didn't read the whole thing. When passing another car at high speed there is a ton of air coming off the the other car and some of it will be pushing sideways into your wheel well when you go by. With no place to go except under your car this reverse scoop      MIGHT   help vent the air out the top of the fender instead of underneath  your car.   Just a thought....

[HPP]

Didn't read the whole thing.

Nope, I admitted that. Based on the photos on page 7 of front tire set ups on actual competition cars, I'd say air migration past the tire is a pretty small part of the equation compared to ram air at 180 mph at the nose of the car going into a 24x6 inch opening.

Also consider that on a high bank oval, body roll is considerably less of a concern compared to suspension travel. This is why superspeedway cars ran huge 1.38" and larger torsion bars. Bottoming out was a bigger concern than body roll.That means less static camber is required, hence angles of interference as implied by body roll and camber settings is also minimized.

Basic aero research shows extreme high pressure areas at the nose, low pressure over the hood, and high pressure again at the base of the windshield. The perfect formula for putting an extractor right over the center of the wheel well.

[xs29j8Bullitt]

Didn't read the whole thing.

Nope, I admitted that. Based on the photos on page 7 of front tire set ups on actual competition cars, I'd say air migration past the tire is a pretty small part of the equation compared to ram air at 180 mph at the nose of the car going into a 24x6 inch opening.

Also consider that on a high bank oval, body roll is considerably less of a concern compared to suspension travel. This is why superspeedway cars ran huge 1.38" and larger torsion bars. Bottoming out was a bigger concern than body roll.That means less static camber is required, hence angles of interference as implied by body roll and camber settings is also minimized.

Basic aero research shows extreme high pressure areas at the nose, low pressure over the hood, and high pressure again at the base of the windshield. The perfect formula for putting an extractor right over the center of the wheel well.

For those interested in the technical aspects of dynamic pressure and the generation of lift, the following at worth checking out.  The first is the best IMO, but only focuses on aircraft.

http://www.witsflyingclub.co.za/lounge/ac01.asp

http://www.grc.nasa.gov/WWW/k-12/airplane/  and  http://www.grc.nasa.gov/WWW/k-12/airplane/dynpress.html  (also try additional links at bottom of page)

http://www.beamthescience.com/index_files/beamdoc/downforcelift.htm  (race cars discussed)

Also see the images below... the first one shows how a car is similar to the airfoil section of an airplane wing...

[Daytona Guy]

Thanks for this info too cool.

This is not all that complicated. A standard wing gets "lift" because the air flowing over the top of the wing takes a longer path than the air flowing under the wing. This forms lift and raises the wing (and anything attached) regarless if the wing is tilted. With the flaps way down (like when a plane lands) counters lift causing the air flow to take almost the same distance. After landing wanting drag they tip up spoilers, flaps extended completely, and the slats extended (stable drag). At take off the front slats lowered and back flaps slightly lowered causing air to travel even farther over the top for greater lift.

Race wings are a matter of how much drag the wing will cause vs how much lift (down force) you desire. The Daytona wing wanted less drag and optimal lift, so this is why it appears they chose the top of the wing to be flat - You get lift (inverted) with very little drag. The wings that swoosh up are usually for lower speeds needing stronger forces with drag not being as much of factor.

http://media.photobucket.com/image/race%20wings/friedwb/BMC/ProductionPP1.jpg





             

                   
           

[HPP]

the first one shows how a car is similar to the airfoil section of an airplane wing...

As a kid growing up in the '70s who buried himself in car mags and spent an inordinate amount of time at dragstrips, I can remember the fledgling funny car class in the early '70 having problems with cars flying off the track exactly because of this problem. Since at the early stages of the funny car class the bodies duplicated their street counter parts with minimal aero aids and speeds that kept rising, eventually there became a point where funny cars would become airborn until the body seperated from the chassis, eliminating lift, and allowing everything to crash back to the ground.

[Aero426]

Here is a very nice shot of the underside of the real #88 fender scoop area.    Metal flanges on sides are turned up so the scoop can be riveted on.   You can see the riveting on the outside edge.    This photo was taken by engineer George Wallace in 2001 on a visit to see the car.   Also note the fender has minimal flaring on the wheel arch.   Minimal flaring = fast!

[Aero426]

Photo of the full #88 fender.    Note minimal flaring on the wheel opening.    The yellow paint is Don White's 1971 color.    Corporate Blue from the #88 underneath, and B5 blue is under that.   Photo taken by George Wallace.

[Aero426]

Fender scoops on McCluskey's #3 Superbird.  Note that the stock posts for attaching the scoops are still visible.   That would mean the area under the scoop was only partially cut away on this particular car.  

[Budnicks]

Whats with the  "429cu.in." on the hood, shouldn't it be "426cu.in."  Just curious...

[maxwellwedge]

I asked before as well.....   http://www.dodgecharger.com/forum/index.php/topic,86849.msg978875.html#msg978875

[Budnicks]

I asked before as well.....   http://www.dodgecharger.com/forum/index.php/topic,86849.msg978875.html#msg978875

Thanks, now I remember that post, I kind of figured it was the NASCAR cube limit or something along those lines, Chrysler guys/teams trying to 1 up Ford or something, just possibly thought it may have been more reasoning than that...

[Aero426]

I was handed this photo yesterday while out and about with Old #7 (aka #47).   It is turn two at Milwaukee, and an angle you seldom see.   Look at the attitude of the front wheels relative to the sheet metal.   You can see that the left front tire on the #47 is not being contained by the edges of the fenders.   Also note the body roll and the relatively large distance from the top of the LF tire to the scoop.     I would like to see what the other side looks like. 

[Daytona Guy]

I have always thought that the tire clearance was an intended miss direction, for the Fords did not have this issue, but if they knew airflow was the intent - this could have led Ford to add this feature.

Just a guess

If it was only for tire clearance (it could have a killed two Birds with one stone) then all they needed to do is flare the top of the fender like they did with the side of the fenders. This was leagal.   

Dane