OK boys,

I need the drag coefficient for a 69 Camaro so I can calculate how much HP it will take to push one 200MPH. No I am NOT KIDDING!!!

The following are the ones for the other Camaro F-Bodies:

Second Gen Camaros: .412
Third Gen camaros: .374
Fourth Gen Camaros: .320 (Hardtop)

Other Cars:
97 Corvette: .290
Viper Roadster Convertible: .550
(what a brick!!!)
Viper Hardtop: .380
VW Passat: .270
(another one that's HT believe!!)
VW Beetle (new ones): .380

Interesting Fact:

At the time, the 1984 Trans AM had the slickest body EVER produced by a GM assembly line with a drag coefficient of .290!!! hard to beleive HUH!!!



[This message has been edited by sr71bb (edited 09-17-2000).]

I don't know the cd, but know it will take lotsa hp to do it. The person to talk to would be LeVan Prothero. He has raced a '67 at Bonneville since almost new. He has gone real fast with it and set lots of records. He ran a big block, and if I remember correctly, around .800 lift cam ? Valve springs were short lived. He ran in "production" classes alot, which would mean unblown & on Gas. Hope this helps some.
Rick
'66 Yenko
'68 SS 427
p.s. The other person to talk to would be the owner of "Big Red". The '69 that went over 220 at the open road races in Nevada. That had to be some kind of ride. http://www.camaros.net/forum/biggrin.gif

[This message has been edited by YenkoYS100 (edited 09-17-2000).]

The 1970 Sports Car Graphic shows a 1970 Camaro with 350 lbs of drag, 325 lbs of front end lift and 40 lbs of rear downforce with NO front spoiler and a small rear spoiler (not the taller one) All at 100 mph

They show a 1970 AAR Cuda with 440 lbs ft lift, 125 lbs rear downforce and 325lbs drag.

You can check your cars actual drag by timing a coast down.
If you don't have a formula for it I'll try and find it in my archives.

There was a great article done by Road and Track or Sports Car Graphic on a 69 camaro and used coast down numbers and they estimated lift and drag and tested spoilers too.

For the 1970 Camaro to go 400 mph you need enough power to overcome 1300 lbs of drag (325 squared) plus the cars rolling resistance.
Add 100 lbs for rolling resistance for a 3000lb car at 200 mph. (source-Chevy Power manual at the back.

I'm guessing it would take around 560 ft lbs or better of torque at the flywheel.

If you double the speed, you must square the drag, and cube the horsepower needed.

I took out what I had figured before because it was wrong.

An awful lot is going to depend on what kind of drag figure you get the car down to.

You can get by with a lot less horsepower if you do that.

Winston cup restrictor engines hit 200 and they are much lower hp but their drag coefficients are below .3 I think.

I've got a magazine article that shows a third gen Firebird Trans Am that went 231 mph with a 650 hp 350 engine and a CD of .235! they used an ice cooling system for the radiator to eliminate air flow to the radiator.
Read this too. http://www.camaros.net/forum/Forum4/HTML/000387.html

Stuff I've read says to have a 1 degree rake or have the front end 1" lower than the rear for best downforce and low drag. A front spoiler and either no rear spoiler if raked enough, or small rear spoiler.
David

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

[This message has been edited by davidpozzi (edited 09-18-2000).]

[This message has been edited by davidpozzi (edited 09-22-2000).]

So Greg,

Are you thinking of doing a little road racing? I have considered taking my car down to Ft Stockton for the Lone Star Challenge. However, I was considering the 120-130MPH classes TOPS.

If I remember correctly, Big Red had a full tube frame chassis. Now that was an awesome car!


------------------
Hugger Orange & white 69 Camaro with supercharged 350, Tremec TKO, and 3.73 12-bolt

See my website updated 9/01/00 at:

www.geocities.com/gheatly (http://www.geocities.com/gheatly)

Hello sr71bb!!

Few years ago RJ Gottlied drove in Nevada silverstate race 1969 stockbodied camaro top speed 230MPH!! engine was allaluminium 540 cid bigblock. I recall it made some where 800+hp,it had 4 speed jerico trans and 17 wheels.rear end ratio got to be 2 and something,as Davidpozzie said torque is key here.try to built as much torque in safe rpm so your engine will live longer.Yes i know nascar engines will rev 8500 500 miles but unless you dont have unlimited budget,stay as big engine as possible and rearratio low.
I have a 69corvette with modified LS7 and richmond 5 speed and 3,08 it goes 170mph,easily,my engine peaks 610 hp at 7100 rpms and 550ftlbs torque at 6000. when i hit the 170,it revs 7300rpm(awsome noise!!)
good luck for your topspeed hunt,dont forget the safety equipement!!!!!!!!!!!

According to my Desktop Dragstrip the drag coefficient for a 69 Camaro is .38, it also says the frontal area is 25 square feet.
Stephen

------------------
67 RS/SS 350 700R4
69 SS clone unfinished
72 454 Weekend Racer

Would any of you have any information on how much affect if any the front spoiler has on a 68? I was running 12.20's at 110 in the quarter, added the front spoiler, and can't do better than 12.34 @ 108. I know it could be a lot of other things, but was just curios.

------------------
David
68 SS Camaro
72 Chevelle
73 Nova Hatchback

Squarles,
Thanks for those numbers.

David,
A front spoiler should lower the aero drag.
Another factor is toe in change, or bump steer.
On a Camaro, the front end toes OUT when the front end raises at high speed with no spoiler.

With a spoiler there should be less toe change as there is less front end rise.

Try checking your toe in at normal ride height, then jack up the front end 2" and check it again.
I'll bet you get about a half inch of toe out!

The same thing happens when the front end goes down, only it toes in.

This can create a lot of drag at high speeds, and affect top end potential.

If you have a rear spoiler and tall rear tires, you might have too much rake angle. The air would hit the rear spoiler harder with a front spoiler added, because the front is now staying lower.
Supposedly the lowest drag setup is to run a front spoiler, with NO rear spoiler, and 1 degree of rake angle.
David

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

[This message has been edited by davidpozzi (edited 09-18-2000).]

Thanks for all the info guys!!! It will, I assure you; have a practical use. As far as the safety equipment goes, I don't imagine it is going to be much use if something goes wrong in a first gen at 200MPH!!!

For all of you that have had certain fantasies and wanted to play them out, I assume you know what I mean.



[This message has been edited by sr71bb (edited 09-18-2000).]

See the Special TOO-Fast issue of Chevy High Performance. Article on 200mph third gen camaro.

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

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

sr71bb,
We have a guy here in Salinas that runs a Pantera in the Silver state challenge. He crashed the car and they rebuilt it with a tube chassis and hand made panels kinda like a circle track version of a Pantera.

He crashed again a couple of years ago. He was in the hospital for some time...
I think he came close to not seeing his wife and kids ever again. But the car saved his ***.

200 is dang fast, be careful and do all you can to protect yourself.

I'd worry about tires the most. One puncture and you are gone!
David

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

I just got the Nov 2000 issue of Chevy High Performance, it features several articles on high speed aerodynamics.
You definitely need to read this...

David

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

Thanks to you all.

I can't hold off any longer, so I'm jumping into this too.

Two questions. First, is RJ Gottlieb's Big Red Camaro still in active competition or did the judge ban it after his 220+mph speeding ticket coming back from the race that year they topped (I think) 223mph???

Second, One article in the Nov. 2000 issue of CHP titled "Life in the Fast Lane" said they are using springs like 950# fronts and 275# rears in an 89 Camaro road racing it at 184mph. Isn't that a bit heavy on the springs????

Somebody fill me in on why that heavy a set of springs are being used because I have the spring spec's on Big Red from an article about it. Like 550# fronts and 200# rears with street radials on it. pdq67

Pdq67,
Good questions as usual.
Remember the 89 uses different suspension components with different geometry and the springs have different leverage over the wheels.

We haven't talked about WHEEL rate here. It's really the wheel rate we should be concerning ourselves with. Not spring rate.

Since most of us here are First Gen Camaro people, we can all compare our actual spring rates because our suspension is all the same.

If you'd like to find your actual wheel rate multiply your front spring rate by:
.356

The rear get's more complicated.
for straight bumps, it's pretty much the rate of the spring, but multi-leaf springs are PROGRESSIVE RATE.

For purposes of anlysing the roll stiffness and how much roll resistance the springs add to the sway bars for determining total ROLL COUPLE PERCENTAGES.
You multiply the rear spring rate by .424 This is for ROLL only, not considered for straight ahead motoring.

I did these a VERY long time ago. So they need to be re done to be shure. They are close for just fooling around with it.
For straight ahead stuff the rear spring rate IS the rear wheel spring rate.

For the front you need to multiply it by the figure I gave.
The same thing happens with the roll bar rate to get to the roll bar wheel rate. The roll bar rate should be multiplied by:
.716

SO- for a 700 lb front spring, the wheel rate is 249.2lbs per inch.
For a 1" 643lb/inch front sway bar the wheel rate for that bar is: 487lbs/inch

The bar and wheel rates get added together when considering cornering roll couple. but not for straight ahead bumps.

These ratios are only used for converting lbs per inch at the spring, to lbs per inch at the wheel. They allow for the spring being rated in lbs per inch and convert to lbs per inch at the wheel.

For every inch the front wheel moves up or down, the spring moves (oops! couldn't find it!) I think it's .59 but it might be off a bit. If the front spring didn't get stiffer when you trimmed a coil off this would work for trimming springs.

Stiffer springs on a high speed car won't hurt if the car is run on a smooth surface.
I've found you can instantly go pretty fast by going stiff but making a car stick better usually involves going softer and softer if there are any bumps.
Stiffer springs would allow you to run the car lower, and make the air dam lower and not hit the road.
(1000 lb and 1500 lb springs are common on second gen camaro circle track cars!)
The bumpier the surface the softer the springs need to be.
I've seen Big Red in a video and you can see a lot of front end movement. On that stretch of road there were some undulations that caused it.
David

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

[This message has been edited by davidpozzi (edited 09-24-2000).]

[This message has been edited by davidpozzi (edited 09-25-2000).]

sr71bb,
IF the CD of your Camaro is .38 and the frontal area is 25sq ft.
It looks like it would take 589 hp at the rear wheels to go 200.

rolling drag of 64 hp
aero drag of 524 hp

1090 lbs total vehicle drag.

That's using the formulas out of the Chevy Power book in the back, if I did it right. I'm no math whiz.

But the good news is if you can reduce the aero drag it will take a bunch less HP to get to 200. If you can get near the low .3"s it should be enough.

What rear wheel HP do you expect?
I'll re run it with that figure, and can tell you what CD you need.
David

------------------
Check my web page for First Gen Camaro suspension info:
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67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

David,

Right now I have 600HP but at the crank (approx. 480 at the wheels). With the overdrive my final ratio would be in the 2.61 to 1 range. With a 28 inch tire, I calculated about 6,100 RPM in high gear to get to 200MPH. I have had the car up to 5,500 RPM before with no problems but I did have some concern about the CD factor.

Can you do a coast down test for me?
Go up to a speed like 90mph and kick it into neutral, when speed drops to a round figure like 80mph, start timing, when it gets to 40 stop timing.
Give me the start and stop speeds, and the elapsed time.

I need the car's weight with you in it too.

Either the road has to be level or do an average of two runs, one each way, so they cancel out the road grade differences.

AND there should be no wind.
Since you have good numbers for power, with a good CD number calculated from your actual car we should be pretty close.

The last trick would be to match the engines power curve to the car's aero drag curve to achieve a theroretical max speed.

I can print out a chart of HP based on your cars drag, and you can superimpose your HP curve on it and see what it looks like.
David

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

David,
Your telling me that the lever arms are different spring and rollbar suspension wise between the two cars. Right?
As in the pivot point being the lower A-arm bushings, next the spring and then the tire.

OK. pdq67

Yes, the geometry could be a bit different.
Not a large amount, but probably up to 20% different.
The sway bar arms are several inches longer on a second and third gen Camaro. That makes their bar less stiff for the same diamiter first gen bar.

AND there is a large difference in how people set up a car. AND the aerodynamic downforce could/should be more, or at least less lift, on the newer car. Firstgen Camaros generally have front end LIFT at high speeds. Unless something is done to prevent it.

I would think you would want to restrict the grill opening some and run a good front air dam to keep air out from under the car.
That would help a lot.
If you get too much air through the radiator, it will build up high pressure under the hood and cause front end lift.
Stock cars use thicker radiator FINS to restrict flow through the radiator. The short track radiators are thinner cores and less fins.

The Chevy High Performance article was well written from what I can tell. I'm no expert on this stuff. I have just studied it a lot and am generally familliar with the principles involved.
David

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

[This message has been edited by davidpozzi (edited 09-26-2000).]

David,

I can post those figures here but it will take me about a week to ten days because my car is currently being color sanded. I know EXACTLY what you mean about NO WIND. On the 5500 RPM run, the car moved sideways three to four feet due to a cross wind that occurred while I was going over a bridge. The generally feeling I got was that the rear end was fairly stuck (I have a rear spoiler) but the front end felt a little light (I have a front spoiler as well). The car tracked very straight. The car had a nose up attitude and never really dropped back down to a stock ride height in the front as far as I could tell.

I would PROBABLY be better off without the rear spoilier and with a little more rake down attitude which I suppose would be easiset to accomplish with smaller diameter front tires. Currently the car height is about neutral from front to rear and has approximately 8 inches of ground clearance. Weight with me in it is 3480lbs.

I probably would have pushed the car beyond 5500 RPM BUT it was at this point that I felt like I had very little steering control which made me beleive the car was starting to experience some unwanted lift ("if she had a set of wings, I know she could fly!").

Anyhow, I will get back to you with the figures so maybe we can figure this out without me having to call on an aerodynamical engineer!!!





[This message has been edited by sr71bb (edited 09-26-2000).]

I calculate 174mph at 5500rpm for your car.

The front end loses weight at high speed in almost all the article I've read on first gen Camaros.

Stock front springs will make it worse as when you loose weight due to aero lift, the soft springs will make the front end rise more and that causes even more aero lift.

I'd run at least 600lb front springs and lower the front end. It made a big difference on my 67 but I had low gears (4.56) and couldnt' run over 120mph at 7000.
The front end stayed nailed to the ground at that speed.

With the rear spoiler, the air pushes the rear down and will cause more front to rear difference in attitude, as you are experiencing.

If you lower the front enough, the air flow will hit the rear deck lid and the spoiler should not be needed. This is according to an article in an old Road and Track magazine. I still like the looks of the rear spoiler and it helps the stability of the car to keep the rear pinned down, so I'm kinda scared to tell you to try removing it.

I think it's better to try and fix the front end lift first.

Another thing is that with the front end lifted the drag goes way up and the front end will add toe IN when it is lifted.

Try jacking up the front end about 2" and measuring the toe in.
OR place something parallel to each front tire, place it about 10" off the ground and about 1" from the side of the tire sidewall, then jack up the front end 2" and see where the tires toe changes.

This can scrub off a lot of speed.

Say, I just saw a friends 69 Camaro and he just bought an AUTOPOWER roll cage for it.
It fits really well, I think I'm going to buy one for my 67. They make a cage or just a roll bar for first gen Camaros. I especially like that the front bars go out very close to the A pillars and give room for the driver's arms near the steering wheel. It clears the stock interior too.
This car had the rear seat taken out and the rear braces went back to the rear wheel well area. I have the custom interor with arm rests built into the sides and the rear braces may have to be re located higher up to clear them if I want to retain the rear seat.

The cage also has rear horozontal cross braces for the seat backs and sholder harness. I think I'm going to ask them if I can get those braces made removable with pip pins. That would make it easy to convert to carry rear passengers. But I'll probably never carry anyone back there anyway.

David

------------------
Check my web page for First Gen Camaro suspension info:
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67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

A thought on front end lift as it relates to spring rate.
A camaro front spring rate is around 325 lbs.

The motion ratio (squared) is .356 so we multiply 325 X .356 and we get. =115.lbs per inch. That's the spring rate at the front wheel.

We want the rate for the whole front end, so we double that figure = 230 lbs.

SO, for every 230 lbs of aero lift, your front end would come up 1"

A rough guess is a stock 69 has 200 to 300 lbs of front lift at 100 mph. If you double the speed you multiply drag or lift by 4, so the 200 mph lift would to to: 800 to 1200 lbs. This is why you see stock cars get sideways and fly off the track at 200 mph!
What you can tolerate at 100 mph becomes 4X at 200!

Added to that is the front end lift created by the engines power transmitted through the rear end acting on the rear suspension's "instant center"
This leverage is a function of the rear "anti-squat"
I'd have to crack the books some to come up with the effect on the front end height, but for argument's sake let's say it's an additional inch over what the aero lift does.

It would be interesting to take a front end photo of your car at speed and then go back to the same place and take another photo stopped.
If we had a way to determine the amount of front end travel we could make a pretty good guess of how much front end lift the car has.

Years ago, race car engineers put visual indicators on the front suspension, the driver could then see how much front end lift or downforce the car had at a certan speed.
David

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

Just thought I'd include the formulas for aero drag if anyone's interested. My numbers are a tad different than David's, which is probably to be expected with different calculation techniques.
Here goes:

Aero drag = CD * .5 * .0019403 * speed * speed * area

.0019403 is the density of air (slugs/cubic feet)
speed is in feet/second (293 ft/sec = 200 mph)
area is in square feet
With a CD of .38 and area of 25, I get 791 lbs of aero drag. Multiply by speed again to get torque, then divide by 550 to get horsepower. This is 421.5 hp required at the rear wheels to overcome aero drag.
By the way, you should probaby do a little more work to determine the drag coefficient and frontal area. It's good that someone supplied the number from their program - but certainly no guarantee that it's accurate. I'd suggest working throught the calculations in Chevy High Performance like someone suggested.

Good luck!

------------------
Matt
http://camarotech1.com
Camaro Tech 1st Generation

I tried another formula from my Carrol Smith "tune to win" book.
Drag HP= Cd X Frontal area in sq ft X (mph X mph X mph) divided by 146600.

I got 518 HP to overcome the aero drag.
I didn't do the rolling resistance part.
That's pretty close to the Chevy Power figure I got of 524 HP.

Matt,
If you got your's from an aerodynamic book it might use a different standard for the air. Maybe at 10000. ft or something else. That would lower the air resistance and the needed HP?
The GM forumla uses .00256 lbs per sq ft for "standard" temp and baro.
Whatever "standard" is!
The more you learn, the more confusing it gets!
David

------------------
Check my web page for First Gen Camaro suspension info:
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67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

Oops, I think I may have made a mistake on that air density anyway. Looking at this stuff too late at night... It also occured to me that you have to consider the other forces at work, again mentioned in the CHP issue. For example a spoiler has aero drag, but in the process of doing its job (pushing the rear end down), it's doing still more work that's drawing from your HP. I still need to read that article in its entirety. Maybe I'll be back after I've had a chance to do that http://www.camaros.net/forum/smile.gif

------------------
Matt
http://camarotech1.com
Camaro Tech 1st Generation

houndog72,
You are right about the downforce or lift causing drag, but it should be included in the total drag Cd figure.
Getting a Cd from coast down method would help but the coast down method measures total drag and includes rolling drag. I'll have to subtract the rolling drag from that to get the car's Cd.

This should be somewhat accurate.
If we have the rear wheel horse power curve, that would increase accuracy a lot as estimating rear wheel HP from an engine dyno sheet and factoring in drive train losses could throw things off.
David


------------------
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67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

Here's a useful link for calculating rolling and aero horse power. http://www.bgsoflex.com/auto.html

David

------------------
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65 Lola T-70 Can Am Vintage Racer

Hey man,

Get the November 2000 chevy high performance magazine. The lead article is custom written for you!!

Lance

How are we coming on this project???

Or is it like figuring springs, do your home work and try them out???

sr71bb, hope you get it sorted out and are able to give Big Reds record a run for the money. Good luck and keep us posted . pdq67

Yeah,

Thanks guys. I read that aero article and it brings up some really scary **** that I hadn't really considered. I just got my car back from the body shop and I am working out a tranny problem now.

As I mentioned earlier, the car has been to 5500 in Overdrive (est. 170 MPH) and the car felt light in front, VERY LIGHT!!! I was running a standard size front and rear spoiler so with what you guys have said and with what the article mentions, I am going to need to change some things aerodynamically specifically in the area of rake angle and possibly 86'ing the rear spolier.

I don't think power will be an issue because at 5500 in overdrive, I know she still had some more to give but I didn't push it because of the aforementioned front end float.

I am going to try and get my hands on a wind tunnel simulation program to see if I can run this on a computer simulation before I break my silly assed neck!!!

sr71bb,

I'm not trying to be a smart a--, but have you ever considered another more aerodynamic car, such as a '53 Land Cruiser Stude hardtop. Like Vintage Air ran at Bonneville at 200mph with his A/C on.

I would just love to see one win one of these unlimited road races with a big Chevy engine in it. The exotic European stuff would have a fit being beaten by a full-bore hotrod '53 Stude. pdq67

I was going to delete the following because it's YOUR car so PLEASE take it with a BIG grain of SALT.

"This way you wouldn't have to modify your Camaro with the required safety equipment soooo much that it really isn't conveneient to run on the street.

I want to make a couple of Bonzai passes with my'67 to see what it will do but no strip in the country will probably let me try it just for me to be able to say that it did run this once without a full compliment of safety stuff. Don't get me wrong because they are right. But to do that to my car to run it twice down a strip to check quarter mile ET's and mph and compare it to Desktop Drag is not the most practical thing for me to do in my circumstances.

BUT SAFETY does RULE!!!!!" All this is my Humble Opinion. pdq67

PS. The Stude has a full old fashioned frame under it,too and yes I've rode in a '51 Commander V-8 and a '57 Silver Hawk at speed (like 115-120mph). The old S.O.B.'s would go down the rode.

PDQ67,

Good point on using a different car but there's just something about the challenge of doing something the vast majority of people people say can't be done.

Aereodynamically speaking what would be the challenge of pushing a car that looks like a rocket ship to 200MPH??? I once made a PONTOON boat run 55MPH and it was a blast because the looks you would get on people's faces when you blasted by was INCREDIBLE!!!

See what I mean???

SR71bb, I might be mistaken but I think I remember you stating that your engine was 450 hp and you have a 150 hp N20 shot on it thus making 600 hp, is that correct? If so when you did this 170 mph blast was this with the nitrous flowing? How long was the nitrous on? That must of been one hell of a ride. I had my car to about 130 mph before and everything felt realy stable until I hit a pretty big dip in the road causing the front end to come up thus allowing air under the car, then it seemed like the front didn't want to come down, so I got scared and lifted.

------------------
68 468 700R4, and here it is;
mutert23 (http://home.earthlink.net/~mutert23/)

sr71bb,

Thanks for taking my post in stride. I do know what you mean. pdq67

Mark,

Yea, you're right on with the HP numbers. I had the NO2 on for about what SEEMED like 5 or 6 seconds. I got the car up to speed without the juice in OVERDRIVE and then I juiced it. It didn't take LONG!!!! What's weird about this whole deal is that time SEEMED like it slowed down because you are so intent on what you are doing. You're listening for odd sounds, watching for vibrations, and trying to gauge if you have any steerability left which I didn't so I lifted!!!

It reminded me of that Smokey and the Bandit movie when just before the end of the jump ramp over that open ravine that hit the button to ignite the rocket and WHAM all hell broke loose!!! What a RUSH!!!!

This same type of thing happens when you are skydiving. You are free falling at 128 MPH and it feels like you are floating in a vaccuum with time stopping temporarily. That's the same type of feeling I had in the car.

[This message has been edited by sr71bb (edited 10-18-2000).]

You know as you approach the speed of light, the apparent mass of gnats will increase dramatically. This can't be good for the paint job!

You know BACKFIRE, I thought about that and on my next BONZAI run I am going to install a BUG SHIELD!!!! Nothing like a challenge!!!!

sr71bb,

Not to be a know-it-all but I think that movie was called Hooper or at least it was Burt's name in the movie, he was a stuntman and the other guy had a tv series Airwolf can't remember his name. It was a cool stunt thou.

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Sean James
67 camaro convertible
454 - 700r4
4:10 12 bolt
69 Firebird

[This message has been edited by mo67cam (edited 10-19-2000).]

Dammit, I've had Sh*t for Brains the last two days!! You are correct. The movie was HOOPER!!!!

Loved the pontoon boat story! http://www.camaros.net/forum/biggrin.gif

Mark

Remember, You can't polish a turd and you can't push a chain. Carry on guys. pdq67

Just thought I would pop in and see what was up with this 200 mph Camaro. It is going to feel light on the top at 170 plus. Chevy didn't design the car to go that fast. And with an overdrive? Whats up with that? Put a wing across the trunk extending over the rear bumber, get the nose on the ground, And get a 4 link and tube struts on the car so that it can be adjusted to stay put. Just like an airplane, that front is trying to grab air and fly. Only difference is once the car leaves the ground, there is no power applyed. They do come down hard. But that is what the safety equipment is for. Anyway, off and running Galen

Hi SR71,
This may be a stupid idea, but what if you did raise the back of the hood like pdq67 was talking about in another post. Would that allow enough underhood air out so as not to cause lift? Winston cup cars have a trapdoor type setup on the roof and I think on the cowl for releasing air when they spin.
Also- I've seen a belly pan type panel on the front spoiler of road race cars that sits level with the ground and runs from the spoiler back to about the radiator support. I'm guessing this is to channel air under the car instead of into the engine compartment. David Pozzi- yes no maybe?
Just wondering- Pete

Raising the rear of the hood was a drag race trick on the 55 type chevies.
I just went to the races at Laguna Seca, the American LeMans series.
The factory Corvettes vent the radiator air out of the hood near the front. This was tried on the old Gran Sport Corvettes in 65, I think.
As you get near the base of the windshield there is high pressure. I guess the rear of the hood would be not as high as the windshield base but not as low as more forward.
Venting of the underhood area would help reduce lift. So would keeping air out of there in the first place.
Nascar guys use thick radiators that restrict the flow of air into the engine compartment. They also use finer screens in front of the radiator.

I can tell you when I put in stiffer springs and lowered my 67 in the front the need/benefit for a front air dam nearly went away.
I think my lower valance panel is as low as most spoilers.
I plan on raising it a little for street use and running as much spoiler as will clear. And ducting the radiator to the grille and shutting off all other air flow.
There is a lot of space just in front of the radiator that can trap air, and too much grille area. I'll try putting black plastic behind the grille where there is no ducting.
You probably only need about 1/3rd the opening in the grill compared to radiator surface.
David


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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 10-20-2000).]

Just yesterday I was looking at old Bonneville pics. that me and my father had taken. I came across Van Prothero '67 Camaro. I noticed that the whole grille area had a custom made aluminum filler panel, that closed off the whole grille area. It was not streamlined at all, but flush with the fenders and upper and lower valence. I'll have to look some more and see if I can find more pics. of his Camaro.
Rick

Rick,
Thanks, I'd like to see it.
David

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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

Hi, I'm new to this message board, I am bringing this post back from the dead (7 years, is this a record maybe? heheh) to bring you guys some useful information regarding 1969 Camaro aerodynamics. The biggest error I've seen published is in frontal square feet. Most figures people are finding is 25 sq. ft. This is incorrect...

The flat square of the width x height = 25.85 sq. ft. Now all the empty space must be subtracted to get the true frontal area.

The method I used was a basic silhouette using a bright light a large distance from a 1:25 model set at stock ride height with a sheet of paper directly behind it taped to the wall. The light was a single source LED placed parallel to the wall inline with the car and centered to the geometric middle of the car. My recordings are accurate to +/- 5% as I used a 1" real size grid to measure it.

These numbers include two stock side mirrors and all use 245 section width tires front and back.

STOCK: 19.64 sq. ft.
1" drop: 19.50 sq. ft.
2" drop: 19.36 sq. ft.
3" drop: 19.22 sq. ft.

Our cars are actually very good for this measurement, ranging from 76 down to 74% of full square. (lower is better)
Oh, with this good news comes the bad: CD is at a minimum, 0.4x.

Thanks for bringing this one back!
Welcome to Team Camaro.

I once overlaid a photo on my drafting program and traced it on a different layer. The computer calculates the area, but I don't remember if I ever finished it!
I also don't recall if I used a 69 or 67 Camaro. I'll have to look for it.

Looking back at my post about the rear spoiler I realize I made a mistake. The spoiler would be considered "Parasitic Drag" I think. Guess I need to re-read my aero books.
David

Can't find the drawing.
Does anyone have a head-on pic of a 69 Camaro?

Sweetblue69, your numbers are probably better than anything I'd come up with.
David

Wow! If I said anything here at all, it would sound stupid compared to you guys. Great thread.

Here's a graph based on the "new" 19.5 SF frontal area and CD of .38 that I used in earlier calculations.
Results are from lowest line to highest on the chart.
1. rolling HP Green
2. Aero HP Red
3. Rolling and Aero combined (total hp required) Black

If you are working with chassis dyno numbers, use the middle line (red), because chassis dyno numbers already have rolling HP subtracted.
David

I can't hold off any longer, so I'm jumping into this too.

Two questions. First, is RJ Gottlieb's Big Red Camaro still in active competition or did the judge ban it after his 220+mph speeding ticket coming back from the race that year they topped (I think) 223mph???

They competed in the Unlimited Class in 2006 with an average speed of 163.932 mph and a maximum trap speed of 172 mph. Quite a drop from 197 average.

Wow! If I said anything here at all, it would sound stupid compared to you guys. Great thread.

Hey Fred, I know exactly how you feel. Every thread David posts in I read. The knowledge he poses is first rate and really shows off his love for these cars :thumbsup:

Thank goodness he's here.

Rich.

Guys, It's funny because I just re-read what I posted long ago and wonder how I came up with that stuff! :)
It must have been closer to when I read some books on the subject.:wacko:

Feel free to jump in and get involved, it's just us bench racin'.

One thing that got me interested in this subject long ago was a top end speed comparison of a Winston Cup car and Al Holbert's 962 Porsche. I think it was at Talladega. The stock car ran faster due to the Porsche's high drag ratio! The wings, ground effects, etc all raised the CD very high, plus their gearing wasn't right-on.
David

I will say that the night I blasted betweem Moberly and Macon, MO at like 145 for 22+ miles flat out I had 29.5" tall M&S tires on the rear and had it raised like 4" more to fit them.. My front tires were my stock D-70/14's and my car was glued to the road at that speed!!

NO spoilers back then b/c I don't think they were even offered in '66??

I could only see about 75 to a 100 feet in front of me on high beam is why I used my twin, Ray-Dot 200,000 candle power spot lights as driving lights..

Boy, did they light up the night!!!!!!!!!!!!!!!!!

pdq67

Paul,
How come you are still alive? :noway: :noway: :noway: :D

My 67 would float all over the place at high speeds. No spoilers stock F41 suspension.
The first spoiler I saw was a photo of the new Z/28 which was either December of 66 or Jan of 67.

David, I used to keep at least 300 pounds a crap in it's trunk at all times back then.

And like I've said before, I had it so stiff that it would almost skip sideways turning a high-speed 90 degree corner in town..

pdq67

for you big red fans

found this

http://www.bigredcamaro.com/newsite/

Annoying music on that site. Makes me glad Disco died!:yes:

I'm starting to hate Shockwave flash web pages. Take forever to load, then show you a bunch of fancy animations instead of what you want to see.
Just my personal peeve. I DO love Big Red though.
David

So our cars with spoilers have a CD of 0.38? Thats not bad! :cool: I like that graph, very cool. So I guess we really don't need more than 410HP to the wheels, the cars will start to fly with those less-than-adequate front spoilers.

I don't recall where I got the .38 figure from. I'd like to see coast down data to confirm it. I doubt the .38 figure was identified if it was with our without spoilers.
The book "Camaro Exposed" by Zazarine lists a 1967 Camaro frontal area of 20.6 Square Feet, a 67 Mustang at 20.3 This is probably with stock 14" wheels as it was pre-production data and no spoilers too.

Here's a page with spoiler history: http://www.camaro-untoldsecrets.com/articles/rpo_d80.htm
http://www.yearone.com/enthusiast/restoarchives/winter99/18-21camaro.pdf

Here's a CD of Automobiles site but a first gen is not listed.
http://www.mayfco.com/tbls.htm

I just recently made block off plates for the front of my grill....and the best part is you cant tell:

http://i27.photobucket.com/albums/c181/SpeedyGoomba/P1010133.jpg

Brian, That's something I plan on doing. Did you block it 100%?
There is a lot of air pressure packing under the front valance that is not doing any good, just creating lift.
David