Author Topic: Some interesting aerodynamic info  (Read 8675 times)

Offline HP2

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Re: Some interesting aerodynamic info
« Reply #30 on: June 24, 2014 - 10:26:52 AM »
Understanding a little bit about how the boundary layer of air works, it is entirely feasibly that a mesh or screen opening covering the entire grill area would have almost the same impact as a flush mounted grill while still allowing enough airflow for the radiator to get through. A few simple angle brackets and some dzus fasteners could make this a bolt on mod for high speed runs that would allow removal for normal street driving.





Offline falkenracing

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Re: Some interesting aerodynamic info
« Reply #31 on: June 24, 2014 - 03:52:58 PM »
Just have to say I love this thread and the experimenting with aerodynamics on these old cars, as most won't go there at all.
Hope it pays of and that more join in as time goes on. (would love to, but got 1000 things to do and only so much time)

Quick q thou, did you ad the front spoiler before? If so, did it do any noticable good? (maybe you've answered that before, and I missed it)

Offline cudabob496

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Re: Some interesting aerodynamic info
« Reply #32 on: June 24, 2014 - 09:27:16 PM »
Well, painted it black (a must) and added a support bar at each front corner of the wood,
going up to the valance.  Took it out today, after also making the rear diffuser about 4 inches wider.
Car between 60 and 80 was very stable, with the nose quite planted. No jumping around or anything.
Definite improvement in that area. (The front spoiler is about a 6 inch by 55 inch piece of sheet metal attached to the lower lip
of the lower front valence. 14 gauge I think. extends 4 inches down) Cooling may have been slightly better than before too, since the splitter makes
for a larger front differentail pressure, I think. It was 90 degrees out today.

Only problem was my tires, when I turn tightly, are hitting the board that extends back to the oil pan, so gotta do
a little cutting on each side, but shouldn't be too much.

Be curious if these mods would impact 1/4 mile times much, but right now I just have my "butt dyno".

But I do feel safer at high speed now. And unless you looked kinda hard, you would probably not see these mods,
being painted kinda a satin black. You'd have to be delibertately looking under the car.

I realize the whole front spoiler and splitter are being supported by the lower front valance.  And, the 2 ft by 4ft board is
supported back by the oil pan, at the sway bars. Gonna try to attach, the front area of the board, to the K member,
so at higher speed I don't end up pulling off the front lower valence.

All these mods are just what the modern cars are doing, to gain speed and gas milage, and improve handling. Except with this 40 year
old car, its whatever you can find at Home Depot or Ace Hardware.

Here's a more modern front splitter:

http://www.bing.com/images/search?q=aerodynamic+challenger+cuda&go=Submit&qs=n&form=QBIR&pq=aerodynamic+challenger+cuda&sc=0-21&sp=-1&sk=#view=detail&id=BC33C561A305D2A5DDDBD890A3D34FE20250EF67&selectedIndex=9
« Last Edit: June 25, 2014 - 02:10:52 AM by cudabob496 »
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline cudabob496

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Re: Some interesting aerodynamic info
« Reply #33 on: June 25, 2014 - 01:41:45 AM »
Just have to say I love this thread and the experimenting with aerodynamics on these old cars, as most won't go there at all.
Hope it pays of and that more join in as time goes on. (would love to, but got 1000 things to do and only so much time)

Quick q thou, did you ad the front spoiler before? If so, did it do any noticable good? (maybe you've answered that before, and I missed it)

Just the front spoiler helped with stability at high speed quite a bit, as the nose would get high and move back and forth above
80.  The splitter now improves things even better, with no real nose movement to speak of, though it is hard to quantify.  The spoiler and splitter
are even more beneficial, as I now have skinny front tires on the car (with 42 psi pressure in them), and they tend to want to move sideways, or jump around, more easy at high speed. I think if you want to take an E body above 80 or 90, you would be wise to do a few aerodynamic mods to keep it more stable and controllable.

May now look at what it would take to bolt a 4ft x 8ft piece of materail between the oil pan and the mufflers. Maybe have a cutout for the finned portion of the trany pan to allow cooling.  Home Depot has 4 x 8 sheets of all kinds of material, besides just plywood.  Also, 13% of a cars aerodynamic drag is from the front tires, so will look at some type of molding to cover them.

If I get some more money, maybe can improve the use of wood with a different thinner material, like plastic or sheetmetal.
« Last Edit: June 25, 2014 - 02:05:07 AM by cudabob496 »
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline cudabob496

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Re: Some interesting aerodynamic info
« Reply #34 on: June 25, 2014 - 01:52:47 AM »
Understanding a little bit about how the boundary layer of air works, it is entirely feasibly that a mesh or screen opening covering the entire grill area would have almost the same impact as a flush mounted grill while still allowing enough airflow for the radiator to get through. A few simple angle brackets and some dzus fasteners could make this a bolt on mod for high speed runs that would allow removal for normal street driving.

And let us not forget the nose on the Superbirds and Daytonas, which put the cars above 200 mph in NASCAR.
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline cudabob496

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Re: Some interesting aerodynamic info
« Reply #35 on: June 25, 2014 - 02:12:54 AM »
check out splitter on 200 mph Cuda, and the flat under-paneling along the exhaust pipes.  I guess paneling over the exhaust pipes,
even if you kept some spacing, might cause a fire.

http://www.bing.com/images/search?q=aerodynamic+challenger+cuda&go=Submit&qs=n&form=QBIR&pq=aerodynamic+challenger+cuda&sc=0-21&sp=-1&sk=#view=detail&id=88F864E8102556670020AFF59C6372DC6D7908AE&selectedIndex=55

Just noticed that the subframe connectors under my car are boxed steel, so mounting some flat paneling should be fairly easy.
« Last Edit: June 25, 2014 - 05:50:17 AM by cudabob496 »
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline HP2

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Re: Some interesting aerodynamic info
« Reply #36 on: June 25, 2014 - 10:01:32 AM »
Also, 13% of a cars aerodynamic drag is from the front tires, so will look at some type of molding to cover them.


Referencing the Winged cars approach, some sort of front fender exhaust venting could help here. Maybe some functional '71 cuda fender louvers to pull air out of the fenders/engine bay.

Offline 'Cuda Hunter

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Re: Some interesting aerodynamic info
« Reply #37 on: June 25, 2014 - 02:39:15 PM »
I agree with that. vented louvers is a great idea.

Bob, are we gonna get any pics of the underside of the car where you have mounted everything?
Really cool that you have noticed a difference in handling from such simple modifications.

On another note, about the superbird top front fender exhaust scoops.
I've heard a few times over the years that those were there for more than just the air exhaust.
I've heard that the wheels would slightly touch the top of the fenders when the bird was at high speeds.
Since the nose and wing would make the car hunker down so far.
They cut the holes to keep the tires from touching the metal on bumps/turns. 
Can someone confirm this?  I have yet to have a superbird to test this.

"All riches begin as a state of mind and you have complete control of your mind"  -- B. Lee

Offline brads70

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Re: Some interesting aerodynamic info
« Reply #38 on: June 25, 2014 - 04:00:40 PM »

On another note, about the superbird top front fender exhaust scoops.
I've heard a few times over the years that those were there for more than just the air exhaust.
I've heard that the wheels would slightly touch the top of the fenders when the bird was at high speeds.
Since the nose and wing would make the car hunker down so far.
They cut the holes to keep the tires from touching the metal on bumps/turns. 
Can someone confirm this?  I have yet to have a superbird to test this.
I'm not an expert ( love that era though! :2thumbs:) but I'd say the tires used were wider than the scoop? Unless they got thinner at speed? :dunno:

Brad
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Barrie,Ontario,Canada
Proud to own one of the best cars ever made!!!!!

My restoration thread 
http://www.cuda-challenger.com/cc/index.php?topic=59072.0
 My handling upgrade post
http://www.cuda-challenger.com/cc/index.php?topic=73985.0

Offline HP2

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Re: Some interesting aerodynamic info
« Reply #39 on: June 25, 2014 - 04:38:05 PM »
The true function of the scoops has been debated ad nausem over on dodgecharger.com in the aero cars forum. Suffix it to say, after 11 pages of debate, there is no clear answer and there is even conflicting data/admissions from the engineers involved in the program. http://www.dodgecharger.com/forum/index.php/topic,85143.0.html

Since then, other cars in other race groups have validated the exhaust theory and it has been used in varying forms extensively over the lat 40 years.

Offline Surfmichaels

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Re: Some interesting aerodynamic info
« Reply #40 on: June 25, 2014 - 06:13:49 PM »
Maybe some high speed racers would have some experience here but a couple of questions that I feel would give some more insight into whats happening at high speed.
How much does wheel alignment and spring rate have to do with stability at higher speed.
What causes instability at high speed? Front end lift? or high speed buffeting?
Did the 70 Transam Cars have any under trays? were they stable at speed? you'd hope so...

Offline cudabob496

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Re: Some interesting aerodynamic info
« Reply #41 on: June 25, 2014 - 06:26:00 PM »
I agree with that. vented louvers is a great idea.

Bob, are we gonna get any pics of the underside of the car where you have mounted everything?
Really cool that you have noticed a difference in handling from such simple modifications.

On another note, about the superbird top front fender exhaust scoops.
I've heard a few times over the years that those were there for more than just the air exhaust.
I've heard that the wheels would slightly touch the top of the fenders when the bird was at high speeds.
Since the nose and wing would make the car hunker down so far.
They cut the holes to keep the tires from touching the metal on bumps/turns. 
Can someone confirm this?  I have yet to have a superbird to test this.

I too read the wheel well vents were there to allow tire clearance.
Yes, will post some photos when things are installed.
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline moparman82

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Re: Some interesting aerodynamic info
« Reply #42 on: June 25, 2014 - 06:35:21 PM »
Those have got to be the biggest exhaust tips I've ever seen on a cuda!
Scott in Omaha
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Offline 'Cuda Hunter

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Re: Some interesting aerodynamic info
« Reply #43 on: June 25, 2014 - 09:13:18 PM »
Which Exhaust tips?
"All riches begin as a state of mind and you have complete control of your mind"  -- B. Lee

Offline cudabob496

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Re: Some interesting aerodynamic info
« Reply #44 on: June 25, 2014 - 09:26:20 PM »
Those have got to be the biggest exhaust tips I've ever seen on a cuda!

yep, 18 inch by 6 inch diesel exhaust tips.
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000