Top Speed 71' Roadrunner

Technical Question and Answer - On topic to 71-74 Plymouth B-bodies only.

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pats71
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Re: Top Speed 71' Roadrunner

Post by pats71 » Sun Jun 13, 2010 9:36 pm

I'm gonna be going with aftermarket 18 inch magnum wheels on my car. Always thought the 14 inch factory wheels looked really stupid on 71-74 b's. I'm gonna be putting a barry grant 750cfm on the 383 along with a slightly larger cam. Other than that I won't stray too far from stock specs.

I know Richard Petty switched to the charger but that doesn't mean he didn't love his roadrunner. Hell he won the Daytona 500 with his 71' bird so aerodynamics can't be all too different. Charger just has hips like the monte carlos :wink:
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ILUV72RRs
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Re: Top Speed 71' Roadrunner

Post by ILUV72RRs » Mon Jun 14, 2010 12:37 am

Yeah, I'm sure Richard may of loved his Road Runner. So long as they were winning consistantly making him money. But facts are facts. The Charger unfortunately is more sleek in the frontend. Which is the first thing that punches a hole in the air for the car. The back of the car only punches the air first. If it unfortunately spins around in a wreck! Hence, why he switched over in 1972 before the race year was even over with. If aerodynamics don't play into it. Then he wouldn't of bothered to go to the expense of switching over to the Charger body. As that cost him money, to make money. Don't believe me? I suspect that you still haven't found a '71 to '74 Charger, and pulled up next to it with your car, and got out to study the front end of the two cars. That's the only way you'll learn. Or go and compare two 1/18 diecast cars or two 1/25 model cars side by side if you can't find the real thing in your area. Yeah, he won the '71 Daytona 500. But Buddy Baker was right behind him on his rearend in the Charger. Driving that car for Richard Petty Enterprises. If you know who signs your checks. You don't pass the boss. Especially the King! Don't get me wrong. I love my '72 Road Runners, and would buy one of those any day of the week over a '71 to '74 Charger. Trust me, it was a bitter pill for me the day I looked at the two cars side by side when I did look at them to see the difference. Aerodynamics might not mean that much on the smaller tracks. But it's everything on the larger tracks when it comes down to who gets there first at the end of the race.

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Smellslike1974
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Re: Top Speed 71' Roadrunner

Post by Smellslike1974 » Mon Jun 14, 2010 10:26 am

The post went from 71 road runners top speed to whats better chargers or road runners. :lol:
"Sunny D"-1974 Plymouth Satellite Sebring With Sundance Packaging

pats71
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Re: Top Speed 71' Roadrunner

Post by pats71 » Mon Jun 14, 2010 2:01 pm

I have only seen one 73' Charger RT in town that has a 400 in it. I'm not able to drive my roadrunner yet as it is in the beginning stages of restoration. To be honest, I'm afraid of even touching it at times. The thing is so original with only 100,017 miles and has the original asbestos brake pads in all four drums. Then when you look behind the drums, the little access slots to adjust the drum stars aren't even punched out. The clutch looks in excellent shape as well.

I know one guy in our mopar club here in san antonio that has his collection of 71-74 chargers. Maybe I can get him to come over here at some point so I can check it out to see the difference in the front ends.
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71Runner
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Re: Top Speed 71' Roadrunner

Post by 71Runner » Wed Jun 16, 2010 3:49 pm

Smellslike1974 wrote:The post went from 71 road runners top speed to whats better chargers or road runners. :lol:

Yes. One question sillier than the next.
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pats71
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Re: Top Speed 71' Roadrunner

Post by pats71 » Thu Jun 17, 2010 12:25 am

Good point. So let me change subject again here and ask which motor would be better capable of handling the higher rpms to reach 200mph? The "B" or "RB" motors?
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road chicken
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Re: Top Speed 71' Roadrunner

Post by road chicken » Wed Apr 29, 2020 4:06 am

Bone stock 71 383 4 speed and 2:76 rear 27 in tires ran 144 mph. It topped out at 5200 rpm. I know it was 144 because my buddies Audi was with me at hitting his speed limiter at the same point.
4th generation B bodys- there is no substitute.
68 383, Street Demon 750, RPM top end,484/284/108 poo poo cam "-5 spd 4:10 SG, 4whl disk, Helwig Anti-Sway, Poly bushings,Firm Feel Box, HD Linkage, 1" t-bars, 7 leafs Springs

gary
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Re: Top Speed 71' Roadrunner

Post by gary » Tue May 26, 2020 12:07 am

Bet a '71 GTX could reach 200 ! LOl :beer:

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sdweatherman
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Re: Top Speed 71' Roadrunner

Post by sdweatherman » Thu May 28, 2020 11:31 pm

Any Satellite/RR/GTX can easily attain 200 mph - you just have to think outside of the box. With your average 71 Ply B-body and driver roughly weighing in at 4000 lbs, and a drag coefficient of 0.47, and the acceleration of gravity at roughly 10 meters per second, it would take about 18 seconds to reach 200 mph. The trick is finding a cliff that is just a little over 1 mile high for the roughly 18 second ride. Now if we can find a high enough cliff, this same 71 Ply B-body could reach a speed of around 505 mph before reaching terminal velocity.
Scott.
1971 GY8 Plymouth Satellite Sebring Plus
1971 GB7 Plymouth Satellite Sebring Plus w/factory Sunroof
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road chicken
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Re: Top Speed 71' Roadrunner

Post by road chicken » Fri Oct 09, 2020 8:53 pm

And going back to RR vs Charger. I've owned them both and had them and by side. I'm not convinced the charger is that much cleaner however, since it had a bulged hood stock they could lower the body over the engine that extra couple inches...keeping the car that much lower to the ground. I also noticed that some of the 71rr pictures of #43 look like the front nose was stretched An inch or two and narrowed by following the body lines. Maybe an illusion, but sure looks like it.
4th generation B bodys- there is no substitute.
68 383, Street Demon 750, RPM top end,484/284/108 poo poo cam "-5 spd 4:10 SG, 4whl disk, Helwig Anti-Sway, Poly bushings,Firm Feel Box, HD Linkage, 1" t-bars, 7 leafs Springs

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