Look we're famous

[Daytona Guy]

Forgive me because I'm sure it's mentioned already in these threads but at what point in the timeline were they cognizant of the fender bubbling problem versus the decree for tire clearance?

Forgive me because I'm sure it's mentioned already in these threads but at what point in the timeline were they cognizant of the fender bubbling problem versus the decree for tire clearance?

Bulged fenders were tested on the 68 1/2 Charger race car (aka the 2x2 cars, one of which became the #71 mule)

The genesis of the tire clearance issues can be found in the following two memos penned by GMW.  Note that he acknowledges that stiffer springs and t-bars were being developed to combat the wheel tracel problem.   Part of this I would attribute to the special build of the 2 x 2 cars and the way they were laid out.  

http://aerowarriors.com/cda/cda_09_060568.html

http://aerowarriors.com/cda/cda_09_062768.html

Where are you saying these "Bulges" are in the fender? Top or Sides?

Dane

[Indygenerallee]

Dane, I think they are on the sides, most pics I have seen the fenders are flared way out on the top.

[nascarxx29]

  Lower profile fender scoops

http://www.freewebs.com/danno340/kkd/68-69_files/69test.jpg

[Aero426]

Where are you saying these "Bulges" are in the fender? Top or Sides?

They were on the sides.  I don't think there is a photo of them that exists.   Same deal with the "reinforced wheels", which had an outer plating of steel with a center opening to access the lug nuts.  They would look something like an early 90's Indy Car wheel.   Must have been super heavy.   

[Daytona Guy]

If the problem was solved in June of 1968 – Why would there be the need for tire clearance in mid '69?
For both the Plymouth and Dodge the 68.5 fender was "pushed up" and the "flange on the right side hood was cut away for the greater tire travel". (documentation given above).

These solutions were only for testing on the track. They were not solutions to ever go into production. The solution was given in the notes, and that was, to get a stronger torsion bar and rear springs.

To say that these engineers gave the orders for tire clearance – would have also given orders for the hood as well. Both were of "equal" concern, yet no order was reported given for the hood to be modified.

If the tire was traveling that much – cutting and pushing of metal is not the solution. The solution is less tire travel for better handling at higher speeds (Note the true engineer's solution). Why would an engineer ask for more tire clearance? That would beg the question of... "Why allow a tire to travel that far?" Engineers want to solve problems, not put a bandage on it.


As for the exhausters, it says... "Mounted above both front tires". None of the E, F, or G series little wind test cars were tested with exhausters. What this shows to me is that this was not the testing ground for them. Were all the tests required to be done on little models for all e, f and g-series concepts? Apparently not. The e, f or g-series tests were not limited to one wind tunnel model, were they? To me it would be ridiculous to do a test on a car like the "little model" for fender exhausters, that does not have moving tires at the appropriate speeds, does not have an engine, or the variables needed to perform a scientific test that the extractor would be tested for. That would be insulting. This kind of a test can be done in other ways on real e, f and g-series cars not in a wind tunnel (unless it was a full size fully functional car). All they had to do is show a 3% less drag on any test mule car. It says they were getting the same numbers on the full size cars - so this tells me they were testing full size cars, does it not?

The jury is still out for me

Dane

[Aero426]

If the problem was solved in June of 1968 – Why would there be the need for tire clearance in mid '69?
For both the Plymouth and Dodge the 68.5 fender was "pushed up" and the "flange on the right side hood was cut away for the greater tire travel". (documentation given above).

The premise of the fender scoop was always as an insurance policy.    You can't add stuff to the package once the homologation process is complete.   Pointer was told to develop something that would not hurt the overall package. 

[Daytona Guy]

If the problem was solved in June of 1968 – Why would there be the need for tire clearance in mid '69?
For both the Plymouth and Dodge the 68.5 fender was "pushed up" and the "flange on the right side hood was cut away for the greater tire travel". (documentation given above).

The premise of the fender scoop was always as an insurance policy.    You can't add stuff to the package once the homologation process is complete.   Pointer was told to develop something that would not hurt the overall package.  

Then, why were they not concerned about the hood? Why was it not mentioned or modified for "insurance" reasons? They carried EQUILL value of concern. Why would these engineers only give direction for half the cure, for a problem that was cured?

Dane

Dane

[Aero426]

There are later pics of the #88 showing the underside of the hood bracing beaten in with a ball peen hammer.    At some point, it was communicated to field modify the hood on that car. 

There is a lot of information in the surviving paperwork.   While it is the only written documentation remaining,  I also feel it is sometimes easy to over analyze and draw conclusions that may not be there.    Sometimes you end up with more questions than answers. 

[Daytona Guy]

There are later pics of the #88 showing the underside of the hood bracing beaten in with a ball peen hammer.    At some point, it was communicated to field modify the hood on that car.  

There is a lot of information in the surviving paperwork.   While it is the only written documentation remaining,  I also feel it is sometimes easy to over analyze and draw conclusions that may not be there.    Sometimes you end up with more questions than answers.  

The documentation clearly says that beating a car to avoid this issue "could not be done for a race", Because it was against the rules, that is why they corrected the problem with "higher rate" torsion bars that were available July 4th of 68.

I would like to see those pics of the 88 showing this...

Dane

[Aero426]

They beat the inner hood bracing on the #88.    Inner hood bracing is fair game.   It does not affect the outer panel.  

[Daytona Guy]

pics?

[Aero426]

Not directed at you.    But I will say again how annoying it is that we already have a recent TEN PAGE thread on the topic with the photos you want to see already there.     There is no new ground being broken here.   Only four new pages of the same back and forth.

If you look at the passenger side mechanic, to the right of his nose, you can see where the inner panel was beaten in.   3/24/70 at Talladega.

[Aero426]

And where the arrow is.   This is March 24, 1970.

[Daytona Guy]

This is an easy fix, and engineers did not give the correction for the hood. The Daytona hood was modified for the latch tray clearance (front ribbing eliminated), so correcting the hood would have been very easy vs handing down ballpeen hammer directions.

Again, this is not what engineers do, that is, give instruction to accommodate poor and excessive travel of suspension. That kind of defeats their purpose in making a car that is designed to win. An engineer would correct the problem, not accommodate it.

Dane

[Indygenerallee]

I can't see the scoop was for tire clearance because it looks like the hood edge would cut the tire before it ever came up to the fender because the vertical edge of the hood rests below the fender when shut you can see in the pic they cut the fender all the way to the top of the fender on the inside. 

[Daytona Guy]

Those pics don't seem to help the cause- because there are sharp metal edges right next to it. Why would you want that?

I think it is an uphill battle for tire clearance without any documentation stating tire clearance. Then with documentation that states "extractors" and "Mounted above both front tires" with "3% less drag" is very hard to say these are untrue statements. Do you agree?

I disagree that we are coving the same thing. If a tire is hitting that hood - I would not want to drive that car @ 200 MPH with tires coming that close to the sharp metal edges of both the hood and fender.

Again this can be proven or disproven - I don't care who's right. The more these discussion go on the more people will have the desire to prove it.

Dane

[Aero426]

This is an easy fix, and engineers did not give the correction for the hood. The Daytona hood was modified for the latch tray clearance (front ribbing eliminated), so correcting the hood would have been very easy vs handing down ballpeen hammer directions.

Again, this is not what engineers do, that is, give instruction to accommodate poor and excessive travel of suspension. That kind of defeats their purpose in making a car that is designed to win. An engineer would correct the problem, not accommodate it.

Dane

Not sure where you are going with this.      Whoever said the wheel travel on the #88 was poor and excessive?     We may not be able to say exactly when the hood was beaten in.   But the setup on the car was ideal for handling whether it was at Talladega in '69 or when they set the record in '70.    But the hood bracing sticks down below the top of the fender.   If you are suggesting they modify the street hood bracing, I don't think that makes sense.     Lots of little things happened on the race cars that have absolutely nothing to do with the street cars.  Note the hood on the #88 has been extended one inch and a lip added to the front edge.  

[Aero426]

I can't see the scoop was for tire clearance because it looks like the hood edge would cut the tire before it ever came up to the fender because the vertical edge of the hood rests below the fender when shut you can see in the pic they cut the fender all the way to the top of the fender on the inside.  

The fender has a metal bead of bar round stock running along the inside edge.  

The hood edge rests very close to, or below the fender.  

The inner hood bracing is below the hood edge.   

[held1823]

Again, this is not what engineers do, that is, give instruction to accommodate poor and excessive travel of suspension. That kind of defeats their purpose in making a car that is designed to win. An engineer would correct the problem, not accommodate it.

an engineer not facing a deadline would. these fellows were in a bit of a hurry.

[Aero426]

Old material from the old thread.

Here is a very nice shot of the underside of the real #88 fender scoop area (and inside edge with bar stock).    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!

[Daytona Guy]

This is an easy fix, and engineers did not give the correction for the hood. The Daytona hood was modified for the latch tray clearance (front ribbing eliminated), so correcting the hood would have been very easy vs handing down ballpeen hammer directions.

Again, this is not what engineers do, that is, give instruction to accommodate poor and excessive travel of suspension. That kind of defeats their purpose in making a car that is designed to win. An engineer would correct the problem, not accommodate it.

Dane

Not sure where you are going with this.      Whoever said the wheel travel on the #88 was poor and excessive?     We may not be able to say exactly when the hood was beaten in.   But the setup on the car was ideal for handling whether it was at Talladega in '69 or when they set the record in '70.    But the hood bracing sticks down below the top of the fender.   If you are suggesting they modify the street hood bracing, I don't think that makes sense.     Lots of little things happened on the race cars that have absolutely nothing to do with the street cars.  Note the hood on the #88 has been extended one inch and a lip added to the front edge.  

The documentation said that the suspension was traveling a greater distance than anticipated. I called it excessive. They modified it on the track for testing purposes, but the solution was the torsion bars. Again, accommodating the greater travel of the suspension was not the goal, but correcting the problem was. They corrected it by July 4th 1968. 

[Daytona Guy]

Old material from the old thread.

Here is a very nice shot of the underside of the real #88 fender scoop area (and inside edge with bar stock).    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!

That picture makes it more scarry. All I see is a sharp edge. If that tire is hitting the hood, then it is hitting that edge. The tire should not be hitting anything. Why would tou want your tire doing that?

[Daytona Guy]

Would you want your tire even having the possibility of hitting that @ 200 MPH

[Aero426]

The documentation said that the suspension was traveling a greater distance than anticipated. I called it excessive. They modified it on the track for testing purposes, but the solution was the torsion bars. Again, accommodating the greater travel of the suspension was not the goal, but correcting the problem was. They corrected it by July 4th 1968. 

I don't think that what happened in '68 relates directly to the #88.    When George talks about the suspension travel in 68, it was not that the suspension was different from before.  But because they cheated and shaved the 2" off the forward part of the rockers, this put the top of the fender closer to the tire.    The #88 was not built this same way.   

[rainbow4jd]

First - I didn't even read half of this thread and the whole idea of jumping to another thread that I didn't even know about.....

Sheesh!

To me... its pretty clear that 3/8ths model testing is solely about aero and nothing to do with final fit finish OR race trim.   So, nothing in the 3/8ths would have been about "tire clearance" - it would all have been about aero.    The "exhausters" can also serve aero EVEN if they were not cut out - only by changing the airflow into the A piller.  i.e. think of it as a two step - the scoops bump the air up before it hits the A piller - lending to a more dynamic air foil effect.

Now get yourself to actual testing.   The first thing to realize is that tires on a race car DON'T track flat - because of camber - they'll run on their edges UNLESS they are on a banked track.  So the supposed tire clearance, may ONLY have been talking about a 2" by 2" clearance spot.  As a result, the fender scoops i.e. exhausters become the NATURAL spot for the clearance  i.e. the location of the scoops were then matched to tire position in final design.


Finally, at 200 mph on a 33 degree bank - that car is going to compress down (at least that's what you want it to do in a race) AND it will compress down (reduce lift) by venting under car air.    For example, the front splitter today is designed to keep air out from under the car.


So.... frankly I think EVERYONE IS RIGHT!    Never designed as tire clearance.  Adapted for tire clearance following mule testing.   Produced with the scouring for the cutouts, because they thought they had too.