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Future Vehicles Modern Muscle with Classic Names
175 messages, Last post on Nov 10, 2008 at 11:35 AM
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Replying to: joe131 (May 13, 2007 1:26 pm) Well, I think a Mopar with a torqueflite and a 2.76:1 rear would be pulling around 3500 rpm  roughly 100-110 mph. At least, I had a buddy with a '66 Charger 383-4bbl, and it pulled 250075 mph. So extrapolating that out, that would come out to 3333100 mph. But 3rd gear in a 4-speed transmission is going to be a quicker ratio than the 1:1 top gear of a Torqueflite. And a Roadrunner is most likely going to be geared quicker than a 2.76:1! So I'm sure that at 100 it would be running quicker than 3500 rpm, let alone 135! Also, those old Mopar engines, even the hairier big-blocks, tended to get their peak hp around 4800 rpm, and would redline around 5500 or so IIRC. In 1972, the 440 six-pack had something like 285 hp, according to the net rating that became the norm that year. It would've been around 370-380 gross. Still, a '72 Roadrunner with a 440-6pack was one of the fastest domestics around by that time. Ford pretty much gave up on performance by then. About the most power you could get was maybe 224 hp out of a 460, but you'd have to buy a T-bird or Lincoln to do it. I think the cheaper Fords and Mercurys were toned down from that. You could still get a 300 hp Pontiac/Olds 455, or a Buick 455 with around 270 hp. Or a Chevy 454 with 270 hp. There was also a 440 option at Dodge that put out 330 hp! Maybe that was a dual quad, and not a 6-pack?
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Replying to: andre1969 (May 14, 2007 6:42 pm) Or is that manual transmission GTX geared for 250 MPH in 3rd gear and 350 MPH at redline in 4th gear?
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Replying to: joe131 (May 14, 2007 8:12 pm)  Now 4th gear is going to be 1:00:1. Top speed is going to be determined mainly by the axle ratio. I'd imagine that about the hairiest axle ratio you could get by then would be around a 4.11:1. Put some fairly meaty 255/70/R15's on that sucker, which according to www.tirerack.com, turn about 720 revs per mile (also 720 rpm 60 mph, and that means your engine would be revving at about 2960 rpm 60. That engine would probably hit its peak hp around 4800 rpm, which would mean about 97 mph. And it would hit its redline of around 5500 rpm at around 111 mph. Now on the flip side of that, I think you could special order a tall ratio axle of around 2.06:1. When you figure that's about half of a 4.11:1, that means you'd hit peak hp at a theoretical 194 mph, and top out at 222 mph! Of course, it doesn't take into account wind resistance, which is going to be fierce once you get up over 100 mph or so. And IIRC, for every doubling of speed, wind resistance is actually squared? I'd say that with a moderate gear ratio, and in tip-top shape, that '72 GTX might, *might* top out at around 145-150 mph. IIRC, some of the fiercest police cars of all time were 1969 Polaras running 440's and 3.23:1 axles, and that's about what they'd top out at. As for turning 3500 rpm 135 mph in 3rd gear? Well, doing the math, I'd take a wild guess and say that would be a 2.45:1 axle? And again, that's not taking into account aerodynamic drag. And I seriously doubt that anybody would put a 2.45:1 axle in a '72 GTX. And you sure as hell don't want to rev something like that up to 6500 rpm! There are many modern DOHC engines that redline around there...some big monster of a 440 that's better at pulling out stumps and flattening mountains isn't going to want to rev that fast without scattering parts for a wide, wide radius! Maybe that '72 GTX came out of Canada, and had a metric speedo! I know a guy in one of my Mopar clubs with a '66 Fury that came from Canada, and it set up that way. |
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Here are some stats from Motor Trend and Car and Driver tests, circa 1971/1972, I'll let the reader decide what he wants to take from this info.These are merely speed/revs figures, not 1/4 mile times. 1971 440-6pk Road Runner, 4.10 rear 104 mph 5400 rpm 1971 383-4v Road Runner, 3.55 rear 98 mph 5000 rpm 1971 440-4v GTX, 3.23 rear 110 mph 4700 rpm Interestingly enough, this '71 GTX did list a top speed of 130 mph 5500 rpm (redline). Another article from Motor Trend compared three different 'Cudas, a 340 auto, 440-6 4-speed, and a Hemi auto. The 340 was the author's favorite, as the 440-6 was just too much of a chore to drive, its carb setup impossible to modulate between moderate acceleration and flat-out. The Hemi was easy to drive, also, just keep your foot out of it on takeoff. Top end on the cars (all at redline): 340 (4.10 rear)- 101 mph, 440-6 (3.54 rear)- 109 mph, 426 Hemi (3.55 rear)-112 mph. Surmise what you will, but I drove some of these vehicles on a daily basis, and trust me, by 100 mph, they were mostly used up and acceleration was pretty slow thereafter. Here's a shocker- Car and Driver tested a Saturn Aura XR that was quicker and faster in the quarter than the '71 GTX! As far as I'm concerned, the golden age of cars is now.
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Replying to: mmcnamara (May 15, 2007 6:09 pm) I'm kinda surprised though, that the car with the 3.23:1 ratio only made it to 110. I figured a ratio like that would be a good enough "middle of the road" ratio to give good top speed without hurting acceleration too much. Sad thing is, though, that I had an '89 Gran Fury ex police car, with a 318-4bbl and a 2.94 ratio. It would top out at about 120 mph, according to the Michigan State Police, at least. Heck, even my old '69 Dart GT, with a 225-1bbl and 2.76:1 axle could break 100 mph pretty easily. I was afraid to take it much higher than that, though. It actually felt like it had plenty of power left at that speed, but I have a feeling it wouldn't have gone much faster. |
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Replying to: andre1969 (May 15, 2007 6:32 pm)
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Replying to: andre1969 (May 15, 2007 6:32 pm) |
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Replying to: xtec (May 15, 2007 7:03 pm) LOL, I do a similar trick with my '85 Silverado in the warmer spring/summer months. I have an old '68 Dodge Dart V-8 air cleaner top that I put on the Chevy. It has the tall 5" or so air filter, and the top part is actually too big to flip. But the Dart's air cleaner, which is flat, sits nicely on top of the air filter and exposes a great deal of it. I don't know how much it REALLY helps acceleration on that dog, but it does seem to take off a bit quicker when trying to merge onto a highway, for instance. And it seems to improve fuel economy a bit, maybe .5-1.0 mpg. Which, when you're dealing with maybe 12-15 mpg to begin with, every little bit helps! It does make it a bit crankier in cooler weather though, and I have a feeling that it screws with emissions.
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Replying to: andre1969 (May 15, 2007 7:24 pm) |
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Replying to: bumpy (Jan 15, 2006 9:11 am)
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