Road Runner Nest

471Magnum wrote:

pats71' wrote:Based on your math you just gave, a 4 speed 3.23 geared car should be able to at least reach 165-170mph. If you add in an aftermarket intake and headers, that should free up the motor to go that much faster.

It's not my math. It's everybody's math.

A 383 is not going to turn over 6000 rpm for very long, and it won't be making any kind of power. 140 tops with 3.23 gears.

Your factory tach and speedo are pretty much worthless at that end of the range, so if you are dumb enough to try it, use a GPS.

Don't forget, the hp required to push a brick through the air at high speeds increases exponentially--that's why folks like Gary build monster motors assuring they can get the job done.

Don't forget, the hp required to push a brick through the air at high speeds increases exponentially--that's why folks like Gary build monster motors assuring they can get the job done.

Exactly. And your hp/rpm curve pretty much does just the opposite. Aero drag gets steeper while HP flattens out.

You may think a '71 Road Runner is more aerodynamic than the Superbird. But unfortunately they're a much wider car. Which means more drag, slowing it down. I luv the '71/'72 Runners. But when a friend of mine back in the day pulled up next to me in his '72 Charger so we could compare the two body styles. It was then I understood why Petty demanded to be switched over to the Charger, and quit running his Runner. When you see the two side by side. You'll understand why too. It looks really fat compared to the Charger. : ( As for the 150 speedo. I'm sure that helped sell a lot of cars. Because guys really believed the car could go 150! As a lot of guys have already pointed out on this question. If you can go that fast in one of these cars. Your engine is really built, and you're taking a big risk of getting killed. Unless you're fortunate enough to rent a race track where you have a better chance of not having a little old lady pull out in front of you because she has no idea you're flying that fast down the road!

Is all this going by just the stock car(not motor wise)?

This was in reference to a stock roadrunner, body and motor wise. Now I'm sure that if you put headers, large aluminum heads, slightly larger camshaft, and rediculously low numerical gears in the back and it could probably be pulled off.

I really don't see the difference between these cars and the chargers since they're both almost the same size but just different body lines.

Could this be why you wanted to make your a super bird clone?

No I just wanted a superbird and always have because I love the looks of them. To me, they always looked so alien compared to any other car ever built.

Yes, I can understand where you may think that the Road Runner and Charger are just basically the "same." But again, if you get the chance sometime to park your Road Runner next to a Charger. Even a '73 or '74 model. I'll be a real eye opener for you. That is, if you understand anything about aerodynamics. Also, Gary Romberg who worked on the original Daytona project for Chrysler. Told me when I interviewed him several times back in the late '70s. That as "trick" as the proposed '71 winged cars looked. No matter what they did with them. In the wind tunnel they just didn't perform as well as the original '69 Daytona.

In 1982 I had my '71 RR going down a stretch of highway with my 150 mph speedo pegged. I was racing my best friend in his Mach 1 with a Q code 351C. Lets just say he didn't talk to me for 2 weeks.
Jim

What was the drivetrain in your car?

What was the drivetrain in your car?

383 4-speed with 3:23 rear
Jim

Speaking of going fast in a '71 B-body...

http://www.youtube.com/watch?v=1MM-Pm22Xt4

Our cars have way too small wheels and gears to go really fast. If you do some math at 100% efficiency, 3:23's put you at about 140mph@5500 rpm. Now factor in wind resistance and a 25% loss of rpm with an old non-lockup automatic, 140 seems hopeful. If you drop it out of a plane at about 30,000 ft that would be your best chance of hitting 200. Or just install the engine in this photo, that should do it. Oh yeah, a 383 will hit 6000 rpm all day long!

73 Charger, 400, 2bbl, 2.76 gears, 255/70/15's... top speed, 148mph over 10 miles of road.. how it was done.. racing a 68 charger 383/4bbl doing the same speed with 3.23 gears. (the 68 was leading me the entire way)