Those are headers with correct length extensions. generally about 12-14 inches long to make the most HP at a small rpm band. If you have headers dumping under a car you have heat, carbon monoxide, fumes, and noise.

These cars sometimes basically run with your foot on the floor for up to 7 miles

 

Lower it as much as possibile, belly pan, open up side vents, ground hugging front spoiler, pace car type rear spoiler, pull off the mirrors, strap down front and rear glass(NASCAR type), good roll cage.
At 160, I had a skidish problem with out the above, in 69/70 racing season. Didn't know about these things till I went to B'ville and saw what the big boys were doing. Got out of it then. Good luck.

 

I don't know if the guy knew what he was saying or not (the field of aerodynamics has advnaced alot in 30 years...) but basically that means those two areas make our car a really bad wing... but a wing none the less!

Also, like gkull has with his aftermarket front bumper, the lower AND farther forward the front spoiler, the better. If the nose sticks out ahead of the spoiler, you're catching air there, and creating a high pressure area. I suppose that means you have to get all of your cooling air through the grilles.

-Chris

 

I made an aluminum pan that all the air coming in the front has to go through my aluminum radiator



My 79 out at the road racing track. since this picture I lower the front about 1 1/2 inches

 

I have a 1980 corvette which have the same body than the 82. The suspension is dropped 1-1/2 inch, I run 17 inch wheel and I corrected the caster to 5 degrees for High speed stability. I took it to 150 Mph and the car feels really stable. The lower lip of the front air damn is really close to the ground (approx 2 inch.). I have only 400 hp and it could run close to 160-165 I guess. The overdrive transmission is the key. You must calculate the proper gearing to get to the selected speed.

Stephan

 

never did 200 mph.. but I had my '68 up to 165 mph and didn't feel unsafe... The car was still pulling strong, but I was worried about blowing my S-rated tires

 

I agree with the above and Gkull. You have the right body style, the '80-'82 is the best for this use. Lower the front as much as possible, get the air damn down as low as you can. Make sure to re-enforce the front air inlet under the front end. If it is not held in place well the air pressure will press it down to the ground and it will dig in (ask me how I know) or it can be flipped upwards and seal off the incoming air (found this one out too) or it can flap back and forth (that is a noise I don't want to hear again). The daytona front end is a good idea, along with side skirts as well. The stock rear spoiler on the '82 should be good enough, but make sure to note on test runs if the back end is coming up at all. At speeds around 200 I would worry about the front windshield coming in, the side windows going out and the rear window exploding out the back of the car. Make sure to seal all this up well and re-enforce (see NASCAR windows).
Since your are ditching the mufflers I would build a pan that goes from the rear end, covers the fuel tank and meets flush with the bottom of the rear bumper cover and goes bumper to bumper. This will keep any drag from the rear bumper cover and the open area between the rear end and the cover from being a big problem.

I also have the wheel wells filled as much as I can and that I am sure helps. As the picture from Gkull shows you can get them up to pretty good speed. I don't have pictures, but I have had my stock bodied 1980 to 140-145 on many occasions for a few miles each time. The car has never felt light or like it was imbalanced. I usually don't push it further because
a: my stock steering scares me.
b: going faster than this is stupid and I shouldn't have even been going that fast
c: The C5's in front of me won't go any faster and I have to lift or hit them
d: all of the above.

The correct answer is "D".

By the way, my 1980 does 145 easily and I am only putting about 250 HP to the rear wheels. I know that 145 - 200 is a big jump. One of these days I will find out how fast 250 RWHP will get you before aero drag takes over, but I have not it yet.

 

I go to Bonneville nearly every year with a group of local racers. Years ago I drove out there in my 79 Vette to find out what changes I would have to make to have a legal car for 200+ mph. So anyway they allowed me to run the short course for an unofficial time because I didn't meet all the safety rules. Then they had some fatalities in the last couple of years and the rules really got strict. I decided that the cost and really butchering my car any further was not worth it to me.

I have the cage. But what I don't have to comply with the rules is:

The halon fire system that sprays down both sides of the motor and on the driver ( about $500 from Summit racing)

Window netting like NASCAR. If you have T-Tops they even
require a netting over your head. Rear window has to have two 1/2 min width metal straps for widow blow out protection. The front has to have clips.

Twin parachutes securely mounted to the frame.

Tires have to be speed rated for the class. I borrowed some 300 mph Bonneville slicks from a Camero racing team that was running in the 227 mph area. That's about another $2000 in wheels and tires.

It only takes low 500 hp for later year Vettes to exceed 200 mph. The flat rear windows models use up an additional 30 - 40 hp to go the same speed.

Traction is a problem and many car add 500 - 1200 pounds to keep the tires planted on what the equivolent of cement covered with sand. I had real problems of not being able to go wide open throttle at 150 mph without spinning my tires.

 

Gkull, what was your first topspeed run without any aero changes? What is your topspeed now with your changes? And what is your hp?

 

I've done a good bit of thinking about this...

I think to pull it off and still retain the body lines a 78-82 type rear window would be needed.

Build a car that has the skin of a C3, dont turn a C3 into a 200mph car. My thinking is a car with a fixed roof, either a convertible styled hardtop car, or a coupe with the rounded back glass. Lay the windshield back a bit farther than it is on a stock car, widen it so that the side glass is flush from the winshield piller back to the b pillar.

The other thing that I would do is use an early model hood, and glass in flush or almost flush to the windshiled a pan all the way around in place of the wiper door/tray. Doing this would get rid of the cold air type intake at the hood... but I'm thinking that getting that point to "flow" would be more helpful than the power!

The other thing I'd do is one of the old Trans am racing tricks... take the front clip off the car, cut out a few inches between the fenderwell and firewall, lower the front 2-3 inches. Its a tapered cut. Takes more out at the bottom than the top. Lowers the front end and keeps the top in alignment.

I'd think about doing a metal firewall/floopan just for the sake of simplicity... If its going to be a race car, make it a racecar that looks like a C3.

Also the old C3 lemans racers had a huge aluminum spoiler on the front to plow the air out of the way... something else to look into.

 

For Nevada open road races in the late 80's I just had the VB&P Salom kit.... and I had fabricated a 5-6 inch hard rubber spoiler in the stock location. The VB&P 550 inch pound springs lower the front 1.5 inches or so and 25.7 inch diameter Z rated front and rear 17 inch wheels

With zero front and rear tire tow in and just under 4 degrees of caster. My stock bodied 79 was speed gun tested out on the two lane highways at 174 mph. My class had a 175 limit or your disqualified. That was with a low 400 hp 355 ci motor.

Later chasing speed I lightened my car and added the 81 Daytona front end roll cage and bigger motors. As I said in the above post I was not allowed to run repeatedly without meeting the SCTA tech inspection requirements. So it was a unofficial one shot 200+ run. Safety rules are in place for a reason. If anything goes wrong in a Vette at even 175 mph your probably dead.

 

I really appreciate all of the input - and the differences in opinion are really valuable.

While there are some great suggestions about super aerodynamics - I think we need to stay as stock as possible - and go 1 step at a time.

As of right now - thanks to your input I can say we will be putting on a big airdam up front - and beef up the intake stuff. Wew already have pins in the front of the hood - we will look at beefing up the rear hinges. We will also consider going to netting on the side windows (safety rules allow for the option of arm restraints in place of the window netting.

I like the idea of filling in the "eyebrow" between the front window and the roof line - But don't know if we can get that past tech inspection.

The car last year ran 163 MPH at 2 1/4 mile and was still pulling strong - we just don't know when the aerodrag will cancel out our available horse power. While it is really tempting to bubble the hood and put lots of cool stuff under there - we want to retain the original line - so we are limitted in what we can do to the engine - beside turbos or superchargers or nitrus move you into different classes.

Keep the suggestions and ideas coming - I will keep you informed as to our progress - whos coming to watch - and whos coming to drive their own vette? World of Speed - Sept 14 - 17 2005!

 

Vroom Vroom

 

easiest way is to get a c5 or a c6

 

Well, you could do that but not with as much style!


David

 

Carl,

If you can get access to a wind tunnel (any aero engr students you know?) you can scale a model and run it at comparable Reynolds numbers. Would make an excellent senior thesis project for someone out there. I wrote mine years ago on air cooling of disc/drum brakes. I proposed building a prototype set of air scoops and doing coast-down tests of my '69 Nova SS on I-64 descending Afton Mountain near Charlottesville, VA. What fun!

 

I don't know about C-6, But c-5's become cooling limited somewhere around 180 mph. The first modified c-5's to reach and maintian these speeds found out that the front end was poorly designed for cooling. An air wall would form and no air was passing through the radiator. Many of them attempted to run with water temps way up over 260 degrees and mobil-1 oil.


New Vette's are not the cheap way to speed.

 

My ford fiesta can do 200 with a JATO strapped to it. I win.

 

maybe the new zo6. Id rather have a c3 though. I think i might try the pans on the bottom.

 

Are you running with the windows open or closed?? Arm restraints and window nets

What "I" would work on first is getting the front end to punch a smaller hole in the air.

A question for you guys... Is a monometer the way to measure underhood preasures? I've been wondering about this for a long time. I've seen x number of lbs of lift mentioned... is this from the area in front of the wheel? I have a hard time envisoning where the "pick-me-up" is occuring! Get rid of that the "stick to the road" happens easier.

By the book, our cars make lift. By driver expierence, those running full length headers get close enough to drag them!

About the "Eyebrow" I wonder if a one piece aluminum panel would do the job. Have it built so it overhangs the fiberglass in the back, bolts down nice and tight... and in the front re-work the trim to cover the front gap on the new cover? Long sentance, but I hope it comes across ok!