The Car Thread

[Captain Goddammit]

Drag increases exponentially with speed.
NO maximum mileage is ever attained in a normal car at high speed. Not even the "hyper miler" guys.
Adding all that extra drag is counterproductive to attaining efficiency.
It's literally against the laws of physics.

But nothing is against the laws of bullshit.

[Captain Goddammit]

Any of you remember the reason for the nationwide 55 MPH speed limit in the '70s?
It wasn't safety.

Ever read how James Dolittle figured out how to squeeze maximum range out of bomber planes, making the war-ending transatlantic flights possible? Hint: it wasn't by flying the planes faster.

I've got a boat, a real water boat... you don't wanna know how bad it gets when you throttle up harder!

[ygmir]

but, isn't there a speed,(depending on shape/aerodynamics), where the air moving around a vehicle changes from a smooth flow, to turbulent and almost creating a "wake" (as in a boat in water), or shock wave of some sort? I know it seems about 60 mph seems what I remember, for a standard 70's pickup shape. Maybe it's way faster than cars go, and I'm not remembering right, either? but, air would flow around a vehicle, like water, yes?

I hate not being a genius and knowing all this.

[Captain Goddammit]

I hate not being a genius and knowing all this.

Just Google it and pretend to be a genius then...

[unjonharley]

In the 70's time of "the gas crush" The whole nation was restricted to 55 mph.. We all saved gas by going slower.. Up to that time I always drove hemmies (@95 mph) never knew the mpg.. Now I have a four banger van.. Tuned and running to BM I get 22 mpg average (with no head wind) @ 55 mph.. If I am very careful with a whole tank I can get 20 mpg in town.. That is more than expected from a big box kite..

[Elliot]

I had to look it up, but you are right. Drag does increase with speed, but it would be felt more on something like amotorcycle than a car and the more aerodynamic the shape the less effect drag would have.The more turbulence caused by the car/mortocycle the more drag.

Look it up some more, my friend, and soon we will have the exact formula.

But again off the top of my head, you are talking about Coefficient Of Drag -- Cd (or some such symbol). A sports car might have a Cd of 0.3, while a pickup might have 0.4. The lowest Cd in the world is the shape of a raindrop.

Roughly, the formula for drag is something like:

Cd x frontal area x speed squared.

Again, probably not precise, but the concept.

Ygmir, it is all a matter of degree, and/but some of the factors change exponentially (thanks Joe, I couldn't think of that word). And yes, air and water behave the same way -- they just have different viscosity. If you wanted to compare MPG between a car and a boat -- PROVIDED THE OTHER FACTORS COULD BE THE SAME (let's say you wanted to compare the internal efficiency of the engines but did not have a test bench) -- you would have to add the fluid viscosity to the formula.

This is a very interesting field. For example, there is something called the boundary layer. The air that is closest to the car-body actually stands still in relation to the car, no matter how fast the car is moving in relation to the surrounding air. Of course, we are talking about a thickness of molecules. Then the boundary layer ends where the air is up to full speed. The boundary layer creates turbulence. Polishing the car helps.

Fun stuff!

[Roberto Dobbisano]

Just Google it and pretend to be a genius then...

oh snap.


dude, did you google that, because THAT'S genius....

[Elliot]

...
Ever read how James Dolittle figured out how to squeeze maximum range out of bomber planes, making the war-ending transatlantic flights possible? Hint: it wasn't by flying the planes faster.

Wonderful point, and there are other examples.... The one you reminded me of is this:
In the same war, Charles Lindbergh was employed as a technical consultant. Being Lindbergh, he flew combat missions (illegally) to really get his finger on the pulse of the airplanes. On a propeller airplane, you can change the pitch of the prop blades while you fly. This is similar to changing gears in a car -- or to be more precise, to change the rear axle (diff) gear ratio, or the diameter of the tires.

The standard factory instruction was to fly with a pitch that kept the engine above a certain minimum RPM. "Lugging" the engine would wear the engine out too soon. Well, Lindbergh was not convinced, and he started flying with a higher prop pitch and corresponding lower RPM -- WHILE MAINTAINING THE SAME SPEED AS THE REST OF THE SQUADRON.

After a while, Lindbergh's engine was disassembled -- and found to have no more wear than usual. The factory engineers had erred a bit too far on the safe side. The operational flight range of these planes was increased dramatically.

[gyre]

Short answer, the ford has a very slippery body.
It's the early aero body tuned for daytona, immediately banned by nascar as an unfair advantage.
Massively overpowered with a high torque engine, 3.25 gearing and very low rolling resistance.
Brakes are Torino front discs on the rear.
Manual trans, of course.
Also lowered, front and rear caps cleaned up by Fat Jack's.
There is no noticeable increase in drag under 120 mph.

Yes, air drag increases with speed, but there is no magic number.
The 55mph limit was all horseshit.
Only my trucks got better mileage at 55mph.

As for wide open throttle, not on that car.
You are barely into the throttle most of the time, even at 80 mph.
Mileage in town is good, maybe because I am completely off the throttle most of the time.
I've probably only had it at full throttle for less that two minutes total.
Rate of top gear acceleration increases to 100 mph.
There is detectable drag at 120 mph and the car settles down and becomes more stable.
Acceleration is seriously slower from 130 to 150 mph.

Have to get back on the truck.
More detail later.

Due to traffic, it is impossible to maintain speeds here now, so I have no figures for specific speeds, but I think it is an accurate guess.
I suspect the mileage peak will be at 90 mph due to gearing.
At 55 mph, the engine would be idling.

[Elliot]

At this point, it might be fun to discuss the weirdness that happened to fuel mileage of many 18-wheelers when the national 55 MPH limit was enacted. We could study cam lobe profiles, and 13-speed transmissions. But jeremiah cricket, there must be all of four of us who care.

So....:




Back to the FUN!

This is my buddy Peter's 1930 model A Ford. I found it a couple of years ago and recommended he buy it. Peter drove a model A as his only car up to 1985 or so, and he missed it. This one is horribly rusty, but drives just fine. And it is bone stock original -- it even has the anti-rattle clips on the brake rods. Peter likes that sort of thing. Only upgrade is 12 Volt electrics. He has installed all new wood, glass, and much else. Absolutely EVERYTHING for a model A is being reproduced! He drives it regularly for local errands. Yes, he's a burner.

[Captain Goddammit]

Gyre you have a '69 Talledega?
There's no one on the planet (out of the few hundred at best) that have one of those and haven't got a single photo!
Boy those are cool, we'd love to see it! You'd look pretty damn cool sitting in it!

It's still a big musclecar brick, with minor aero tweaks aimed as much at creating downforce as increasing slipperiness. And those are minor tweaks on a car that was no raindrop to start with!

I have a '79 Trans Am. I'll post a pic.
It's more aerodynamic than a Taledega. It's got even taller gears (2.56). Why can't I hit 20MPG with it?

[gyre]

Thought I said.
Early aero body Tbird, 83-84.
Nothing so rare as a Talledega.
Ford went back to a conventional rear very quickly when the body style wasn't allowed.
Shocking what the first owner paid for the body, because they were so new then.
Built by Seyfer Automotive in Denver and Fat Jack's in california.
As far as I know, it was the first custom aero bird built.
A later one built by Fat Jack's has custom steel bodywork everywhere but the roof.
Barely recognizable, but can run wide front wheels, the real handicap I have.
Quarter of a million in that car.
I talked to the owner.
He didn't even know everything in the parts count and only has one tiny photo of the car.
He was trying to sell it, but wouldn't take anymore photos.

My car is in no way as radical as that one, of course.
It was built as a V8 analog of the turbo Mustang and Bird ford were building.
Originally had a turbo 289, massive power, but peaky.
Changed to a blown 289, it sucked hardware on the track right through the mesh on the K N filter and destroyed blower, heads and block.
That's when the 408 was built.
Far less power, but very even delivery.
Needs computer remapping badly.

It's the car I crashed in, awaiting time to restore it.
The engine and suspension survived.
Lost all the cooling gear.
Very hot running engine, requires a constant fan running under 50 mph, due to the aero body.

I can vouch for the Eldorado body being rare.
This is caddy country and I've rarely even seen one.
Beautiful car.
Wonderful stuff, Elliot.
I really envy the permeation of car culture in california.
I would definitely love being there for that.

[mgb327]

.

[Captain Goddammit]

What are the headlights on that Model A from? I can almost place them but not quite.
I guess that's a "Rat Resto" lol.
I've always wanted a "real" hot rod, something like a '29 roadster pickup or chopped '29 A sedan on '32 rails or a '34 or even a T bucket (but those are too scary for me!!).
I had all sorts of American iron back in the day - they used to be so cheap! I had a '70 GTO convertible, that cost all of $2500 back in about 1985. I should dig up a photo of my beautiful red '67 Camaro, 327 4-speed, that I paid $2000 for in 1988. It only lived another few months and my girlfriend at the time rear-ended a Subaru with it.
I had a '72 Chevelle hardtop that I dropped $400 on in the early '80s. There were lots of other ones too, all cheap then, would be valuable now.
The Trans Am and '55 Chevy are the only ones I managed to keep all this time, and the Trans Am is only beginning to be worth anything at all. It's only got 77k on it though. I almost never drive it or the Chevy.

[Simon of the Playa]

i miss my beautiful seafoam green 1963 newport (the "lost" year) with pushbutton transmission.
it had a hula girl on the dash too...


le sigh...

[media]

[unjonharley]

We had a 29 Model A for a farm car... Older sister wanted to learn to drive.. I drove the ford across the road into the hay (stubs) field.. Showed her how to get through the gears and told her to work it out.. She got to close to the wet land and stuck the car.. I harnessed one of the draft horses and pulled her out.. She drove about a tank of gas and got her drivers licence about a week later. Lot of good ole stories go with that Model A..

[Elliot]

Captain, you are correct, there are a couple non-original items on Peter's model A -- I forgot about that. The headlights, and the seats. (There could be others.) Somebody stuck a pair of newer seats in there. They look 1960-ish, with proper tilting backs for rear seat access -- maybe Mustang. We have no idea what the headlights are from.

As for T-buckets being scary... sure, they can be. (A "T bucket" is like the first version of my red one, with no hood, but usually shorter in the front, so more weight is on the front axle.) Big-time hot-rod builder Roy Brizio (son of Andy Brizio, who practically mass produced T buckets in the 1970s) once told me to never hook up the transmission kick-down linkage on a peppy T bucket. Which makes good sense -- if you have a 400 HP big block in the nose of a 90" wheelbase.

But.... My red one had longer wheelbase, with the engine well behind the front axle. And only a stock 283. And lots of heavy stuff toward the rear -- that body was a "boat anchor" of wood and fiberglass. The car weighed...

*pulls that old file again*

...2,500 pounds, with only 880 on the front and 1,620 on the rear. (Probably with me in the seat.) Drove like the proverbial dream, yet had the T bucket look. (Until I added the hood with pointy nose -- then it became a "track roadster".) So I say it is perfectly possible to build an outrageous-looking car with decent handling. (Thank you Chrysler Corporation, for teaching me much of this enginererering stuff at your now-defunct MoTech school in Detroit!)

[tatonka]

my 72 ford 360 AT ,made it thru one burn

[media]

[Captain Goddammit]

OK, here's a ride in my '55. You'll have to excuse the starter that sounds like a beer can in a blender, the motor all dirty, and various other crap - this was my hot rod when I was 20-something and I'm now 40-something, and the car's barely been touched since.
But my brother-in-law Ian and I dusted it off and went for a spin (that's him in the brief face shot) and he shot this video.
I've still got it, and in fact the trans is out of it right now to replace the starter and flywheel, and that ugly set of exhaust headers.

[media]

[MikeGyver]

my 72 ford 360 AT ,made it thru one burn ]

My parents just bought a 67 Ford camper special with the 390, motor home was too much of a hassle so they are gonna try the camper trailer route.
They're going through the electrical right now, too many hack jobs done through out the years to try and chase the shorts.

[tatonka]

my 72 ford 360 AT ,made it thru one burn ]

My parents just bought a 67 Ford camper special with the 390, motor home was too much of a hassle so they are gonna try the camper trailer route.
They're going through the electrical right now, too many hack jobs done through out the years to try and chase the shorts.

yes I have many bad wires , so I ran new lines and switchs . 360 plugged along ok , felt underpowered. transmission will be gone thru before next year.

Cpt Goddamit nice 55 , I had a 56 2dr post at one time in 1976 . I have had close to 80 vehs in my time , use to get old cars for 10.00 - 50.00 dollars in the 70's
old 50's and early 60's cars. Once had a perfect 1961 chev 2 door with red interior , was pretty , got it for a 8 track tape deck that i had paid 10.00 for
Made a profit on almost all of them, some we detruction derbyed stupid kids . I bought a 1960's plymouth 4 dr hardtop , baby blue with big fins, had a large block
motor with a cracked block ( leaked water ) got it for 15.00 and my buddy got a early olds and we took them out to his parents farm feilds and had a DD .
Got alot of them from old ladys who husbands had died and they had no use for them anymore. If only I could have stored them somehow
Got only a few pics of some , changed hands on alot of them fast.

[Thecatman]

my 72 ford 360 AT ,made it thru one burn

Beautiful truck!
My 95 Ford F150 4x4 has taken me to the burn four times. It's taken me to the Black Rock Desert just for kicks several times as well as camping near Duck Flat. 300 ci with a 5 speed. I've had the truck since day one. A year ago next month I had to replace the original clutch. The last weekend of October I have a three dayer so I'm gonna replace the fan clutch which pretty much quit working.

[Jackass]

That straight six with the manual transmission will last forever...and won't leave you short on torque when you need it

[tatonka]

http://www.flickr.com/photos/24796741@N05/

[Agaton]

http://www.flickr.com/photos/24796741@N05/

I'm often too impatient to click on links. But glad I clicked on this one. Don't miss it!

[AntiM]

Wow.

[Thecatman]

That straight six with the manual transmission will last forever...and won't leave you short on torque when you need it

Ford put the straight six was in medium duty delivery trucks (UPS vans, tractor/trailers for city uses etc).
Problem I have is when I ordered it from the dealer I was more concerned with better mpg, at the time, so I ordered it with rather high, 3:31 gears, in the differentials.
It still has the original starter and altinator. Don't know if I spelled that right.

[Captain Goddammit]

A long time ago I drove an F600 medium-duty tow truck with the Ford 300 six. We called it "The Creeper". It was slow but it always got where it was going.
I had a '65 Valiant 4-door that got sideswiped all the way down the right side. The car was so ugly I always said the wiped-out side looked better than the straight side. I yanked out the motor and got a straight Duster to swap it into but never did it. (Motor/trans/chassis compatibility issues I didn't yet have the ability to deal with). That 225 Slant-Six laid out in the back yard a few years; a friend needed one so I gave it to him. He bolted it in, right off the ground, and was still driving it years later.

[Captain Goddammit]

I could be wrong, but I believe the engine with the lowest warranty-return record (so theoretically most reliable, at least by that measure) wasn't the Slant Six, but the old Dodge 318 V8!

Come to think of it, I don't know if that means the original "Polysphere" big block 318 (totally different engine from the early '60s), or the ubiquitous small-block 318 that they built for half of forever. I'm assuming it's the common small-block we all know.

[Thecatman]

I could be wrong too, but wasn't the Chrysler 318, 360,and 383 the same engine block?
Like the Ford 272, 292, and 312, from the late 50s into the early 60s.