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

Started by xs29j8Bullitt, October 05, 2011, 07:00:03 PM

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Based on the evidence so far, the fender scoops are for:

Tire clearance only, just like the Chrysler guys said!
Tire clearance initially, with un-intended Aero improvements.
Tire clearance AND Aero improvements by design from the start.
Aero improvements by design, possibly some minor tire clearance improvement with NASCAR mods.
Aero improvements only, fender stiffener edge and hood stiffener are tire clearance limiters.
It allows the HOT temperatures to escape, generated from the tires that moving at VERY high speeds. 150-200 mph

hemigeno

The only problem with merging the two threads together is that it'll get REALLY confusing when going back through it... the forum's software will mesh all the threads together according to the date the reply was made - regardless of the continuity in logic between the reply immediately preceding or following.  IMHO it will make the "conversation" more difficult to follow. 



moparstuart

GO SELL CRAZY SOMEWHERE ELSE WE ARE ALL STOCKED UP HERE

Indygenerallee

Sold my Charger unfortunately....never got it finished.

Ghoste


cdr

LINK TO MY STORY http://www.onallcylinders.com/2015/11/16/ride-shares-charlie-keel-battles-cancer-ms-to-build-brilliant-1968-dodge-charger/  
                                                                                           
68 Charger 512 cid,9.7to1,Hilborn EFI,Home ported 440 source heads,small hyd roller cam,COLD A/C ,,a518 trans,Dana 60 ,4.10 gear,10.93 et,4100lbs on street tires full exhaust daily driver
Charger55 by Charlie Keel, on Flickr

Stevearino

Regardless of what the published stories of what the fender outlets might have been designed to do I can tell you that their effect would have been to provide more front down force by evacuating the higher pressure air from the under hood area . Downforce (nascar term) or negative lift is achieved through an air pressure differential. If you look at the Nascar gen 4 cars or what we called the common template cars before the COT you will see they have flat angled fenders. One would assume that this if for the air to press on them to force the car down. To a degree that is true but the real effect of that particular shape is to speed up the air along the leading edge of the wheel opening causing an evacuation effect of the high pressure air under the front of the car. The lower air pressure verses the higher air pressure on the top of the hood area creates significant downforce. The reverse fender scoops on the Daytona and Superbird would have sped up the air flowing over them and drawn the air out from under the hood area. Check out the Can Am cars of the era and you will see they have similar features with louvers over the front tires.

Indygenerallee

QuoteRegardless of what the published stories of what the fender outlets might have been designed to do I can tell you that their effect would have been to provide more front down force by evacuating the higher pressure air from the under hood area . Downforce (nascar term) or negative lift is achieved through an air pressure differential. If you look at the Nascar gen 4 cars or what we called the common template cars before the COT you will see they have flat angled fenders. One would assume that this if for the air to press on them to force the car down. To a degree that is true but the real effect of that particular shape is to speed up the air along the leading edge of the wheel opening causing an evacuation effect of the high pressure air under the front of the car. The lower air pressure verses the higher air pressure on the top of the hood area creates significant downforce. The reverse fender scoops on the Daytona and Superbird would have sped up the air flowing over them and drawn the air out from under the hood area. Check out the Can Am cars of the era and you will see they have similar features with louvers over the front tires
X2
Sold my Charger unfortunately....never got it finished.

Daytona R/T SE

Quote from: Stevearino on June 24, 2013, 08:17:50 PM
Regardless of what the published stories of what the fender outlets might have been designed to do I can tell you that their effect would have been to provide more front down force by evacuating the higher pressure air from the under hood area . Downforce (nascar term) or negative lift is achieved through an air pressure differential. If you look at the Nascar gen 4 cars or what we called the common template cars before the COT you will see they have flat angled fenders. One would assume that this if for the air to press on them to force the car down. To a degree that is true but the real effect of that particular shape is to speed up the air along the leading edge of the wheel opening causing an evacuation effect of the high pressure air under the front of the car. The lower air pressure verses the higher air pressure on the top of the hood area creates significant downforce. The reverse fender scoops on the Daytona and Superbird would have sped up the air flowing over them and drawn the air out from under the hood area. Check out the Can Am cars of the era and you will see they have similar features with louvers over the front tires.


Yep.

Same idea here:



Daytona Guy

Quote from: Stevearino on June 24, 2013, 08:17:50 PM
Regardless of what the published stories of what the fender outlets might have been designed to do I can tell you that their effect would have been to provide more front down force by evacuating the higher pressure air from the under hood area . Downforce (nascar term) or negative lift is achieved through an air pressure differential. If you look at the Nascar gen 4 cars or what we called the common template cars before the COT you will see they have flat angled fenders. One would assume that this if for the air to press on them to force the car down. To a degree that is true but the real effect of that particular shape is to speed up the air along the leading edge of the wheel opening causing an evacuation effect of the high pressure air under the front of the car. The lower air pressure verses the higher air pressure on the top of the hood area creates significant downforce. The reverse fender scoops on the Daytona and Superbird would have sped up the air flowing over them and drawn the air out from under the hood area. Check out the Can Am cars of the era and you will see they have similar features with louvers over the front tires.

I 100% agree with you (this above).

Fact:
They are called "exhausters"
They are documented as gaining a percentage of better aero - 2%
The actual aero engineer for the Daytona project (who was not a car guy) talked about keeping as much air from going under the car as possible, where He said it, "gets chewed up", makes the car more stable and slips through the air better. I would imagine the air flow CFM out those exhausters at 200mph was tremendous. All that air, if it was not for the exhausters, would have no where else to go than out the fender well, or under the car. The vacuum it creates also aids in down force (suck the car down- not push), all be it very minor.  

Until someone can prove the tire will rub on a circle track Daytona - I'm unconvinced it is a tire clearance issue. The only place they said they rubbed was the side of the fender where they had to bulge the fender out.  

The only convincing photo, but weak, is the tire hitting the hood, and that is because the reinforcement was so low, and if so, the only proper answer for the tire rubbing the top of the fender and the hood would be to cut the top fender and hood bracing and everything in-between. This could all be solved by pulling the torsion bar and observe the travel on a race Daytona.

Dane

Daytona Guy

Speaking of COT and Nascar. What is wrong with Toyota? What were they thinking with the acronym TRD????? Turd  :smilielol:

Dane

Stevearino

Quote from: Daytona Guy on June 25, 2013, 12:17:24 AM
Speaking of COT and Nascar. What is wrong with Toyota? What were they thinking with the acronym TRD????? Turd  :smilielol:

Dane
:smilielol: :smilielol: :smilielol:

Ghoste


Daytona Guy

At least Mopar sounds cool - The Toyota Racing Division ??? Come on Foreigners, understand the language you are working with. Change your acronym to Toyota Racing or Toyota Racing Team. Not TRD! - It does not even sound cool, or tough. They also put that logo on their trucks, and boy their trucks look like turds. There are two place where USA still seems to have the edge, Trucks and modern Muscle cars. Go USA. Fart cars will never take the place of Muscle.

Dane

winged69

I don't know about anyone else but the only airflow that I get is that all dirt and rain and mud seems to come out the hole and then the scoops direct them to my windshield. And what comes out is really very lttle.
To really direct air you would need to open up the inner fenders to allow heat and airflow through the scoop openings from under the hood.
My feeling is it is for tire clearance, when you crank down the torsion bars the top of tire gets pretty close to the spot the scoop is. It would scuff the tire pretty good. High bank tracks would also force the inside tire up into the wheel well and may hit fender.  Just a thought with a little experience.

pettybird

Quote from: winged69 on June 25, 2013, 01:27:51 PM

To really direct air you would need to open up the inner fenders to allow heat and airflow through the scoop openings from under the hood.


The race cars had HUGE holes underneath them the size of the scoop. 

pettybird

Quote from: Daytona Guy on June 25, 2013, 12:00:49 PM
Toyota Racing Division ???


The D is for development.  Still dumb that they write an acronym that looks like 'turd' on so many Tacomas.

Kinda like the Ford joke that says , "well, at least they circled the problem."

Daytona Guy

Quote from: pettybird on June 25, 2013, 01:33:36 PM
Quote from: winged69 on June 25, 2013, 01:27:51 PM

To really direct air you would need to open up the inner fenders to allow heat and airflow through the scoop openings from under the hood.


The race cars had HUGE holes underneath them the size of the scoop.  
You made my point - there are no inner fenders in the race cars. It's all open.

Guess where it would hit first in this picture? See the openness of the bay?




Dane

odcics2

With hood closed it's the inner hood brace. The dimpling you see by Fred Schrandt's head was done that day, as the car progressed nearer 200 mph lap speeds.
And, there is a slight indent on the driver side inner hood, too.
I've never owned anything but a MoPar. Can you say that?

ACUDANUT

I still agree with this: It allows the HOT temperatures to escape, generated from the tires that moving at VERY high speeds. 150-200 mph

HPP

Problem with that theory is tires only run around 150-180*. If venting tire heat was critical, there would be a similar vent on the rear quarters as well. Stevearino is pretty spot on with his assesment of aero benefits.

C5X DAYTONA

: :horse:   Guys,   When Pointer first drew the car there was no extractor.    Wallace quotes are still and have always been,  "when we (Engineering) saw the drawing for the first time we asked Pointer to push up the fender on the right front.  We are close there already."    Wallace states,  "why not, we are allowed to with the new Daytona.  We could not push up the fender on the Charger and Charger 500 as per NASCAR Rules to the existing body.   What Pointer did to the fender was up to him.  That was his expertise."    Now, that written 3% on the recommended package is the only test that can't be proven in more ways than one..   Chrysler documents state that "all test were to be done on the 3/8 car.  No full size test."     Photos and documents show all these 3/8 Daytona test...  And yes, those test were all done on the 3/8s car and they are all to my knowledge,  documented and photographed.    Now here is a major point.....  That E-Series 3/8s car is still around.  It was given to Winged Warriors by Chrysler in the 70s.  It doesn't have any holes or hole repairs in the top of the fenders.  So how was the 3% tested?  3% is HUGE and there is nothing to show how they got that number.   There is only one 3/8s E-Series car.      My feeling is exactly what ALL the engineers say.   Clearance.     Now if Pointer had other ideas.  That is fine.  But he was told to make clearance first..    Wallace is quoted as saying, "Pointer worked feverishly on them to make sure they had no aero affect."  So some where, some how Pointer did test them.  But that was after being told to make clearance.     What ever happened on any full scale test car including the #88 was after the fact.   Tire hitting the hood, stiffer bars, shocks and so on.    It was for first for clearance and Pointer made sure they got what they wanted and he made an extractor.  Maybe it did double duty (looks like it did)  but the original purpose was clearance on the right front only.       Some talk about why not put in bigger bars.   Yes you can and will need to do that since there will be more positive down force.    But you can't do that till you have the body ready.   They didn't have computers to magically tell them what to do.  They had to try and test many combinations over and over.       
Caution.... Low flying aircraft.

Daytona Guy

These pictures are just hard to reconcile with claims. I'm not saying it is not possible for it to be a tires clearance issue, but how can these pictures justify the possibility of it being true? There is no way this tire's path will travel to hit where claimed. Now in the 68 car that hit the top, did it have narrower tires? Unless the upper control arm is absolutely really really short, or it is like a VW bug and did not have one, there is no way this tire is hitting anything. It even looks like this tire and suspension is only designed to travel a few inches.

I'm not ruling out though that the initial idea was a concern over tire clearance, and then lead to the actual an aero reason was for venting. Another reason was that the S-Bird has them, and they changed the design that would allow for greater evacuation.



C5X DAYTONA

Quote from: odcics2 on June 25, 2013, 03:23:45 PM
With hood closed it's the inner hood brace. The dimpling you see by Fred Schrandt's head was done that day, as the car progressed nearer 200 mph lap speeds.
And, there is a slight indent on the driver side inner hood, too.
Who gets the honers of putting the dimples back into the hood? :lol: 
Caution.... Low flying aircraft.