I know driving first gen. cars at high speeds is roughly equivalent to trying to get a brick to be aerodynamic, but I was just wondering what types of problems are associated with 100+ mph driving and if there are any remidies for them. Thanks.

Actually Penguin, the first generation Camaro's were among the first automobiles to be actually designed on the drafting table with aerodynamic properties. And with front and back spoilers, that actually are functional and not just for looks, and the gustafson mod if you have the time and money, you can achieve what i think is remarkable handling at high speeds and on all road types.

One significant thing is the front spring rate. Stiffer front springs will keep the front end down. A slight rake will help too.
The rear spoiler actually makes so much downforce, it pushes the rear down and causes the front to lift up! So as you go faster the rear gains weight, and the front gets lighter.

Years ago Road And Track did a test of the Camaro spoilers. They found the best balance was with the only a front spoiler, and no rear spoiler. This test was done on a totally stock 68 Z/28 I believe.

If the front is lowered a lot a front spoiler is not neccesary.
Of course, lift at the front will take weight off that end of the car and the springs and swaybars were designed for a heavier weight. Thus the car will have too stiff a rate in roll at the front and cause hight speed understeer.
David

Actually the first generation camaro was one of the first cars GM did extensive wind tunnel testing on.

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68SS ZZ4, 4sp T-10, 12 bolt, getting painted

78Z28, 330hp vortec, TH350, 10 bolt (just finished)

In addition to the front and rear spoiler I would try and control the air passing under the car. I would construct plates that went between the radiator support and the front valances, upper and lower. Remember that the air that goes through the grill has to go somewhere the only place for it to go is under the car. As an example look at any Trans Am from the 70's.

Steve R.

Thats exactly right Steve R, but do that and you will run into overheating as you know. That stumped the Camaro designers as well. the less air under a given car of course, less lift, better handling.

I thought it would have the exact opposite effect. If you force any air that passes the grill through the radiator wouldn't it run cooler. As an example, all first generation Firbird's equiped with either A/C or 400 engines recieved such block off's from the factory.

Steve R.

I always thought the camaro had a nice sleek design. Now the 55 chevy, thats a brick!

SteveR makes a very good point. If you look thru your grille you can see there is a lot of flat surface surrounding the radiator. The air can stack up against the radiator support, it will then either have to go thru the radiator or go down under the radiator support. You want enough air to cool the engine but not pressurize the area under the hood causing lift.

I really have to repeat that if the springs are stiff, and ride height low. 100mph seems like nothing.
I can remember when my 67 was stock, I thought I would fly off the road at 130. When I set the car up for autocross with guldstrand springs front and rear, it was rock solid at 115 mph at 7000rpm with the 4.56 gears i'd gone to. Funny, I stopped getting speeding tickets when I changed to the 4.56 gears!
I'd also removed the front spoiler as the car was too low for it. Now, according to what I stated about the Road & Track article. I ran the reverse setup from what they said was best. But as far as I could FEEL, it seemed fine. But it probably was not optimum. I think stock soft springs make the aero trim more important. Of course, if you double the speed the drag is quadrupled! Rolling resistance is pretty linear by comparison.
David

Misread what steve wrote. Punish me guys but please dont leave permanent marks. Ya, I have 15x60's in the back, 14' x 60's in the front and I have an lift situation when I start going over 65. I have always had front spoilers on my other Camaros, and that has always corrected the problem perfectly. But the guy before me had all the gears set for top end and had a rear spoiler. Now why he didnt put on the front spoiler makes no sense to me. My front spoiler is being primed/painted now, and I'll be all set.

Oh BTW, today i was taking a right turn and this guy that was parked started to pull out right when I was on the side of him. There was a van behind me that was in the lane I just departed. It was because of my power and quickness that got me out of an accident situation. WHO SAYS HP IS A BAD THING !!
www.geocities.com/macgse/68CamaroRS.html (http://www.geocities.com/macgse/68CamaroRS.html)

How to make your 1st generation Camaro stick to the ground at high speeds?
Well, if you look at the Vintage Trans Am cars they really did basic stuff like lower ride height, body roll, roll centers, etc. There is a book out called "how to make your car handle" that starts with the basics and goes into the tech stuff. I recommend it. http://www.camaros.net/forum/biggrin.gif
Stiff springs, performance shocks, big sway bar up front, solid or poly bushings everywhere, a roll cage, tie the frame together, using a close ratio steering....on and and on and on...
The Nascar boys often to increase downforce is to block as much air into the grills as possible without overheating. Try blocking
air by using clear plexi-glass behind the grill but leave enough for air to keep passing through the radiator.
Take a look at BIG RED its a 69 Camaro that ran at the Silver State Classic a few years back and it ran I believe just over 220 or 230 MPH. http://www.camaros.net/forum/cool.gif There are films you can buy with that car in it or past car mags with lots of articles. The web too is a good place to surf. Good Luck and keep your speed runs for the track.:P lol yea right. http://www.camaros.net/forum/biggrin.gif

[This message has been edited by Toby T. (edited 04-04-2000).]

[This message has been edited by Toby T. (edited 04-05-2000).]

David asked me to post about this topic in here,so here goes..

Coefficient of drag for the first gens?
I have absolutely no idea.

None the less i can hand over some advice for logics sake.
Cd(coefficient drag) and Cl(coefficient lift) together makes up for a common nomer known as Cw-which is as useful a number as blinkerfluid is a product.
Drag is obviously a product we want to minimize at any cost(well almost http://www.camaros.net/forum/smile.gif)
Lift in the proper amounts however is something we want.

None the less.

One of the major obstacles(sp) with a car from an aerodynamic standpoint is that it basically operates with two mediums.
It runs IN one and ON another.
If we view the projectile(the car) within its boundarys we soon realize that when we move it forward it will displace whatīs in its way.
Air.
This air has to go somewhere,and it does.

When and how is what we measure,alter and try to work to our advantage.

As noted tho,what is normally NOT paraphrased is what happends to the amount of air pressed into the crease UNDER the car.
This air will ricochet(sp) between the undercarriage and the tarmac(or whatever surface weīre on)and bounce like a rubber ball back and forth producing turbulence in ways that are VERY hard to measure and/or keep track of.Worse yet the turbulence will alter with surface material http://www.camaros.net/forum/smile.gif)
Ergo...
When i went to school(aeronautics college)we did a little empiric testing on an old VW bug.
What we did was to simply bolt a common piece of sheetmetal to the front bumper and record how the performance of the car altered(top speed).We altered the height and shape of this sheet to hearts contents and measured our brains out.
The simple fact was that ALTHO WE INCREASED THE PROJECTED FRONTAL AREA OF THE PROJECTILE THE PROJECTILE WENT FASTER THE LARGER THE SHEET GOT!

It is important to understand that the "R"(resistance) of the projectile is a function of mass density of the medium,frontal area of projectile and speed square amongst other factors.
In other words a given Cd and Cl with increased projected frontal area will increase resistance for projectile in case in theory.
None the less the car went faster the bigger the "spoiler" got.
So..what was/is at play here?
The turbulent "currents" under the car..
They can produce VAST amounts of resistance.
Ergo..a lowered car will normally be faster then a stock one.
A car with increased positive rake will work the same way..

ANY time you put a "90deg" block in harms way you will increase drag right?
Not necessarily so..
See..thing with air(and any other medium for that matter) is that to get things in or onto the projectile is has to have some sort of way to get out.If it doesnīt nature will make sure that flow is stoped in its tracks.
Case in point..
Blocking off the radiator inlet.
As you make the effective opening smaller and smaller the less air will be able to go through because less air will be able to get out.Simple.(Altho the intake and "exhaust" bottle neck in this case is the same thing)
As a result the air will take other ways around the projectile and the "bad" Cd will diminish-making the car go faster.

Whatīs lazy and busy areas of a car ca be investigated by very simple means.
A common roll of wooltufts and a roll of tape will go a long way.If you want to add numbers to that you can make up a simple watermanometer to take readings in inches of water(which can very easily be translated to inches of mercury or whatever).Dye water red or similar for ease of reading.(You make one up by taking two similar diameter tubes and put them on the same height on a board.You then connect the two tubes with a hose.Mark the board with height readings.Leave one of the upper ends of the two tubes open to the atmosphere and the other by a hose to the area you want to check.Itīs a crude instrument,but it works..)
Please be adviced tho that these readings are VERY sensitive to the gas law.
In other words they will alter with temperature and barometric pressure.
Reference is 15deg C and 760mm of mercury(10" of H2O)Also known as sea level ref.
So if you want to be able to crossreference the readings from one day to abother you have to alter ALL reeadins to sea level.

The difference in static and dynamic pressures over and around a car can be mindboggling to say the least!
In other words,to check the effect of for instance a rear spoiler you simply measure the difference in water between for instance the cars interior(which you have referenced earlier for the day at hand) and different places before and after the rear spoiler.
Have in mind that a simple cam corder is a valuable tool to the investigator.
Make records of readings and speed.

Same deal and thinking can be carried to the extreme.
Wheel wells.
Cowls.
Engine bay(remember temperature differences)
Aso aso aso.

Beuty of this is that all it takes is work and some gas money.Pen and paper-or a pooter if you want to get elaborate.Stuff you need to make up the tools are nickle and dime money.
You will son discover problem areas that might need to be adressed and areas that have laminar good flow.
Please be adviced tho.
DO NOT put a manometer hose in direct proximity of the cars body or undercarriage.
Put it an inch or so ABOVE(use duct tape or whatever).Reason for this is that the "hardparts" of the car will have whatīs called a boundry layer of air that the "interesting" air will flow upon.
Guess you could say that the first couple a millimeters of air will "adhere" to the car.

If you wanna know more,just ask.

Jesper

------------------
DVC-2001.Racing
495 cubes of fogger injected thunder in a 71 z-28.
Viking thunder (http://home.swipnet.se/mechanixracing)

Mail me at
racings email (http://dvc-racing@telia.com)

Whew !!! http://www.camaros.net/forum/eek.gif That was a mouthful. I hope you never have to call me and leave a voice message !!

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<A HREF="http://www.geocities.com/bh3chevy/Bobs_All_Chevy.html" TARGET=_blank>69 X22 Camaro
68 Camaro
72 Nova SS
82 Corvette
</A>

uuuuuhhhhhh? Could you repeat that?

Jesper,

You bring back old memories of playing around the wind tunnel at the University of Missouri at Columbia, when I was in engine school.

My classmates and I had to see how a scale model of a big Pickup truck and bed camper changed the lift, drag and (I think) yaw as we whittled on it to lower the simulated camper and round its leading edges. Boy, it was fun.

I think what you are trying to say is that the smoother the under-carriage of our cars is the lower the C/d.

And the last time I looked the wind tunnel was torn out years ago. I don't know if the University moved it or sh-t-canned it. But I do know that it was a "hyper" wind tunnel that was used for such things like re-entry vehicles every once in a while!! pdq67

Racing,
Thanks, that's a great post!
I once built a manometer and got readings in front and behind the radiator, but I didn't know what to expect them to be or how to analyze the readings I got.
I used a clip board to hold the paper and got some tiny valves from an aquarium supply to enable me to shut off individually, each of the 5 vertical hoses.
All I had to do was shut them off when up to speed and stop and mark on the paper the water levels.
But, once I had some readings, I didn't know what was good and what was bad!
For instance, should a radiator have a high pressure in front of it and a low pressure behind it? If there is high flow in the duct, I guess pressure would be lower?
It get's tougher when you look at the details.
David

------------------
Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

[This message has been edited by davidpozzi (edited 03-22-2001).]

AWWWWWWW!! BONZAI runs, what a blast. Although lately I have been more into the cosmetics of my ride you guys may have remembered a couple of months ago we discussed this in terms of what it would take to go 200MPH.

I think we decided at the time it would take 650-700HP and some big gears (and even bigger balls!!). At higher speeds the first gen's front end has a tendacy to get LIGHT so we talked about that being a problem. That's one of the reasons the rear spoiler may not be such a good idea for the HIGH speed passess!!!

I DO KNOW for an absolute fact that at 170-175MPH a first gen with basically a fairly stiff BB setup and both spoilers basically has VERY LITTLE contact with the ground and steering is pretty much non-existent!!!

Pdq.
Yeah,we had one of those too.(A scale tunnel that is).Fooled around a LOT in that tunnel let me tell you!

Dave.
For the sake of simplicity.
As far as less important flow donīt bother with the numbers.Look at what facts you get instead.In the case of a radiator-or any cooler for that matter-you have two criterias that needs to be fulfilled.
1 is to get airflow through the cooler in the PROPER amount to carry away the heat wasted(BTU;s-British Thermal Units.) at very varying roadspeeds and loads.2 is to have some sort of control of the airflow from an aerodynamic standpoint.
Naturally this entails that you will have a pressure drop over the radiator.If you flow the air to fast it will be of lesser use as a cooling medium.Playing around with what happends AFTER the radiator however is the big leagues-thatīs hard.Also have temperature rise in mind here..

Also remember-with a logical mindset-that pressure and speed is interconnected.
This is known as Bernoullis law.
In short..when pressure rises airspeed will decrease and vice versa.
When talking harmonics(as this field of expertise wasnīt hard enough already.. http://www.camaros.net/forum/smile.gif)have in mind that pressure and sound are interconnected too.Speed of sound is the reference in that case.
In the case of harmoncis the airspeeds discussed can have the need of VERY large forces.
See..as i mentioned the resistance of the projectile is a function of speed squared.
Now that problem is that this holds true until you start to reach the soundbarrier where the function will incrase to a factor of 6.This rise looks sort of like an inverted x2 curve in graphic form pretty close to the sound barrier.On the other side of the barrier the factor will actually decrease again(as youīve punctured the "wall") to a factor of about 1,5.

Even more important tho..
After the air is "split" by the projectile is will reconnect at some point after the projectile-as nature strives for status quo.
This area where the two streams meet is known as the wake area.
The wake area can be controlled to some extent by the end profile of the projectile-in other words how the two airstreams leaves the projectile at hand.
Idea is to get the wake area as far away from the trunk of the car as possible because the wake area is for the most part very turbulent in action-and therefore less predictable.
What the turbulence does is make the effect of any downforce less-as we now know that to get air ONTO the surface we need to have an efficient way to get RID of it,and the turbulence makes it harder for the air to do so.
Hence the reason for the early stages(80;s designs) ugly chopped off rears on cars.

If you take a look at the current crop of rear wings on for instance a pro mod car it just doesnīt look much like a wing now does it.
It rather looks like a piece of aluminium sheetmetal with a divider on each side.
So how does it work?
Wake.
Logic mindset on please..*drumroll*
What it does is to effectively make the path for the air longer.
Altho the "spoiler" in this case is mounted to the trunklid or similar it will effect the airstream coming up from beneath the car too,as it will make the stream pass backwards and up to interconnect with the stream from the topside.
Now having the mass of the air in mind we soon realize that altho the two streams might have left the car as an entity the streams will still move-as weīve applied force to said mass of air.
With the same reasoning in mind we can now visualize that the point of impact for the two streams will be moved up and rearwards of the car due to the spoiler-effectively moving the turbulent area to a spot further away from the car making more downforce possible due to a more laminar flow.

Ps.The hard part in my case is really to express this in layman terms,and trying to make it understandable.If and when i strike out in that respect just tell me so and iīll try and rephrase.Ds.

Jesper

------------------
DVC-2001.Racing
495 cubes of fogger injected thunder in a 71 z-28.
Viking thunder (http://home.swipnet.se/mechanixracing)

Mail me at
racings email (http://dvc-racing@telia.com)

For the newbie aero guy, would a logical first step be to fabricate a panel along the lines of an air dam where the front spoiler is ( or behind it) to block off as much air as possible going under the car? I realize we have to contend with ground clearance and demolishing the item but maybe some type of flexible skirt would work?

In the most recent edition of "Camaro Performers" Mag they have an article about Steilow's Thrasher and its fun on the road tour last year. They have a great shot of it as it is going 165 down the back straight of a roud course and the front is riding pretty high. The article makes a mention about how the front spoiler was not up to snuff in doing its job.

I have also heard somewhere (in some magazine article) that the Camaro's short rear deck and curve of the roof going down to the rear cause the rear end to want to lift at high speeds. Anyone else know anything about that?

Rick.
In a word-yes.
I for one would make one up from aluminium first,just to check out the performance properties of the airdam.
Follow that up by attaching a lower part of wear resistant plastic-which is commercially available these days.
Frankly tho,after being content with the layout of the spoiler iīd make one up from carbon fibre.
There are several reasons for this.
First of all it would be flexible.
Second-altho flexible-it would still be resistant as hell to cracks(which most plastic isnīt)
Third-carbon fibre on a 30 year old car is cool as hell http://www.camaros.net/forum/biggrin.gif

Working with carbon fibre in this case does NOT need to be an act of alkemi.
In fact itīs fairly easy.
We just made a set of carbon fibre intake stacks for my Hilborn this winter.Made a plug in the lathe and went at it.Single layer works just fine with carbon fibre in non load situations.

Here;
http://home.swipnet.se/mechanixracing/6mindre.jpg

Itīs about as working with fibreglass more or less,altho the cutting of the carbon mat needs some pretty serious cutters no to spoil the mat.

------------------
DVC-2001.Racing
495 cubes of fogger injected thunder in a 71 z-28.
Viking thunder (http://home.swipnet.se/mechanixracing)

Mail me at
racings email (http://dvc-racing@telia.com)

[This message has been edited by Racing (edited 03-23-2001).]

Nice engine!
Is that pre preg mat or if not, what type resin did you use? Is it Polyester or Epoxy resin?

Another aero question. My vintage race Lola T-70 has just a flat aluminum plate vertical spoiler screwed to the back of the tail.
Would an angled back plate spoiler be better?
I'd guess a small wing would be best, but I'd like to try and get about the same downforce as I have now, but reduce the drag while staying with a spoiler.
David

------------------
Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

What do you think about blocking off part of the grille to reduce air pressure in front of the radiator support?
I have a 67 camaro and am thinking of drawing air from under the bumper as there are two pretty good sized openings there. And blocking off either all or part of the grille to reduce front end lift.
I think a sheet of thick black plastic behind the grille would not show up when looking at the car from the front, and wouldn't rock chip.
If I need additional air I would open the plastic up in the center.
I plan on using an aluminum radiator, and it would protect the core from rock damage, and bug plugging too.
Nothing looks worse than a damaged aluminum radiator core!
I sometimes run road courses and when overtaking another car they throw rocks back at you if they drop a wheel off the track.
I've been hit by a rock in the face shield while driving the Lola at 130mph!
I went right out and bought a THICK lexan face shield!
David

------------------
Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

Great info guys! Just to answer the original question, my Desktop Drag 2000 software has the Cd for a '69 Camaro at .36 .

Racing,

What do you think of the old '60's hot rodders trick of raising the back of the hood to let the air out of the engine bay???pdq67

pdq,
I think that wouldn't be needed if less air were gettting into the engine compartment.
I hear the NASCAR teams use more resrictive raidator fin density to inhibit air flow into the engine compartment where it causes lift by pressing up on the hood.
They can tune the front lift by what radiator they use!

Huntsman,
Do they give the frontal area of a Camaro?
If not, does it give the aero drag in lbs at 100 mph?
thanks, David


------------------
Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

[This message has been edited by davidpozzi (edited 03-23-2001).]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Huntsman:
Great info guys! Just to answer the original question, my Desktop Drag 2000 software has the Cd for a '69 Camaro at .36 .<HR></BLOCKQUOTE>

That sounds pretty low for a 32 year old car!
No wonder we're so fast. http://www.camaros.net/forum/biggrin.gif
Joe


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69 396 w/SS Trim, B&M TH400, 3.55 12 Bolt Posi, Blue w/White Z28 Stripes, Chrome Rally Wheels
Badboatdude@CS.com
69 Pics http://albums.photopoint.com/j/AlbumIndex?u=1506559&a=11674961

Racing: Shrrrriiing!!! What an engine.

David - would you also fabricate some type of deflector on the 67 to move the air stream to the radiator front? BTW - I'm very please with my Griffin radiator.

my desktop drag says the frontal area is 25.0 for a first gen.

Rick,
I'll try some kind of air dam on it to increase air pressure in front of the radiator, and also reduce air flow and pressure under the car allowing the radiator air an easier trip under the car.
I've heard the third gen's were set somewhat up this way and if you accidentally tore off the seondary air dam that was back behind the front spoiler, the car would not cool correctly.
The third gen has a nice setup and I'd like to do something similar but the 67 Camaro lower valance pannel is too far rearward to allow air to be bounced up into the radiator in the same way, so I am thinking of ducting through the large holes below the bumper on each side of the liscense plate.
I'll also put some kind of screen in front of the radiator to protect it.
I hate the look of a dinged up aluminum radiator! Especially after spending a lot of money for one!

Guys, thanks for the drag and square footage numbers.
David

------------------
Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

how much does rake have to do with the current and does a 2 inch drop up front with smaller tires represent a significant change in front height and aerodynamics? also, what are the top offenders when it comes to the camaro being slippery?