1998 Grand Caravan

OK, post just one technical reference to them. Just one and I'll admit here in print that I was wrong and you were right. Just one...

Matt

ROTFLMBO!!!!! Gawd you are sure full of funny statements.

If a ratio results in a reduced ability to perform an operation or function for a given input, the ratio is less efficient.

Lever anaology: the longer the handle side of a lever, the more efficiently a person can do a job for a given input force.

And changing final drive ratios and adding underdriven transmission ratios results in greaterr efficiency.

For someone that keeps putting me down you have very little grasp of reality. Obviously you are set in the ways you were brainwashed into.

No, I don't have to post anything. Efficiency: the ratio of input to reslutant output. If your output isn't within the design parameter, it's either more or less efficient than required. Overdrive ratios are inheriently inefficient. the proof is the almost mandatory need to shift down to a lower ratio to climb a hill UNLESS YOU'RE TRAVELING AT A SPEED FAR ABOVE THE POSTED SPEED LIMIT.

The true fact is it wouldn't matter if I did. You'd just wave your wallpaper around and find some fault with it, most likely, my high school education.

Sure, Roy, just follow these two around. It's dripping off them like sweat off a rabbit in hunting season.

ROTFLMBO!!!! Well, you just stuck your foot in it. According to the Summers Brothers, the car was wind tunnel designed to handle 500 mph, then the engineers determined the engine outputs and ratios needed. And they blew it.

The real life facts call you a liar. Besides, lowering the final drive ratios would have resulted in an unusable first gear due to the slick salt conditions, a slower acceleration and no speed record.

No.

Like I said, and your attitude continues to prove it: it wouldn't matter if I did, mr bigot engineer.

Btw, how about you explain how the marvelous inventions of the past 6000 years came about before your ilk contaminated the Earth?

Sorry, I didn't write any technical manuals at the time. . . I was too deep in grease and oil.

Of course, I also didn't think I was going to have to finish your education for you.

No, you didn't, but you did try to DENY me the option to be selective.

Yes, I'm sure correct statements are pretty funny to someone without a clue about physics.

No, it isn't more efficient at all as you have to move the lever farther to accomplish the same amount of work on the other end. The longer the handle the less force is required, but more distance is required in direct proportion to the reduced force. Since work is a force acting through a distance, the end result is no change in efficiency at all.

Since you aren't able to show the math or physics as you several times claimed you could, here's a really simple example using a lever which you claim to understand. I won't complicate things with gears, but they are just two levers touching each other, but that adds a little complexity and you don't deal well with that.

Definition: Efficiency = work out/work in (the / means "divided by")

Here's a reference simple enough that you should be able to understand it:

Definition: Work = force * distance (the * means "multiplied by")

Again, here's a pretty simple reference (high school level):

Now we have a lever that is 10 feet long with the fulcrum in the middle. Let's say we put a 100 lb. weight on one end. If we move the other end of the lever down by 1 ft we will lift the weight 1 ft. The work out is the work done on the weight, which is 100 ft-lbs. The work in is the work done by whatever pushed down on the lever and this is also 100 ft-lbs since we had a force of 100 lbs acting through a distance of 1 ft. Thus the efficiency is 100/100 or 1.

Now shift the fulcrum such that it is 9 feet from the weight and 1 foot from whatever or whoever is pushing on the lever. Now to lift the 100 lb weight, we will have to push down with a force of 900 lb. You keep claiming that we have now lost efficiency since it now requires more force on the lever than before. However, let's do the math. Again, let's raise the weight 1 ft to keep the work out the same as before at

100 ft-lbs. How far does the lever have to be pushed down to raise the weight 1 ft? Since the ratio is 1:9, we have to push the lever down only 1/9th of a foot to raise the weight one foot. So how much work does this require? It requires force * distance or 900 lbs * 1/9 ft which equals ... drum roll please ... 100 ft-lbs. Now lets calculate our efficiency again. It is equal to 100/100 or 1. Doesn't this sound familiar? Let's see, why yes, it is the SAME as when the ratio of the lever was 1:1. Imagine that, the lever ratio doesn't change the efficiency at all. :-)

If you equate understanding basic physics and math with being brainwashed, then I'm guilty as charged. OK, I demonstrated pretty clearly above that changing the ratio of a lever has NO affect on the efficiency of the lever. It changes the ratio of forces, but has ZERO affect on the efficiency of work/power transfer.

Now it is your turn to show a clear example that supports your assertion that changing a ratio does change the efficency.

Matt

Right, you don't have to, but you also can't. The need to shift down has nothing to do with efficiency, and has everything to do with torque multiplication which is an entirely separate topic.

That is where you are wrong. You post one single reputable reference that supports your claim, and I'll concede that I'm wrong and you are right. I don't care what your education level is. I only care that you are claiming physics support for an argument that isn't based on physics. I wouldn't care if you had a Ph.D., I'd still point out the fallacy of your argument.

This is the classic "I lost the logical argument and now need to bail out" statement. No matter what I do you will just keep picking on me. I haven't heard that since grade school.

Matt

I didn't say you had to have written the reference yourself. Feel free to post any link, book citation, SAE paper, whatever you like. It just has to clearly say that gear or lever ratios change the efficiency of power transfer.

Yep, another "I've lost and now how do I save face and get out of this predicament" statement. There is no shame in being ignorant, but being unwilling to learn is very shameful.

Matt

You have yet to show a real life fact. That is why most cars are pushed several hundred yards down the run by another vehicle. Have you ever actually been to Bonneville?

I knew you couldn't, but it has been fun watching you try to weasel out of the hole you've dug.

You mean the attitude that simply is asking you to provide even one fact to back up your claim?

Since you've conceded above that you are wrong and unable to support your claim, my work here is finished. However, Bill is usually more persistent than me so he'll probably entertain your ignorance a little longer. :-)

Matt

Keep your thumb here - you'll need to come back to that sentence of yours.

Oh really? What tense of the adjective is that? Sorry - adjectives do not have 'tense'.

Again - adjectives do not have 'tense'. Looks like you could have used some more of that there book-learning that you despise so much.

No - no problem with Merriam. What's really sad is you think you're in agreement but are not.

Here - I'll use the two words in a sentence (though not sure why I'm wasting my time): "33% is the *accepted* power loss figure on the 300M Club for the 42LE transmission, but those same people complain about that huge amount of inefficiency and think that it is not *acceptable*."

If the two words mean the same thing, then you have to not believe that it is possible for the same person to accept the 33% figure, yet consider it as unaccpetable inefficiency in a transmission. If you can't understand that, then there is no hope for you.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Hi...

Here's the answer for you all. You're simply using the word "efficient" differently.

To the engineer it's simply a mathematical formula. ie; 12 volts in and 11 volts out equals blah blah blah.

To the mechanic; it's more practical. ie; if you can't reach the ignition key to crank the starter, then it's blah blah blah

There it is, now all of you sit down, have a beer or whatever, and get back to helping others and each other fix your cars efficiently :)

Ken

Exactly, that is what we've been trying to show Budd. He claimed his argument was based on physics, so I used the physics definition of efficiency. He then started making up his own definitions, but continued to claim they were based on "physics."

Maybe his definition of physics is also other-worldly. :-)

Matt

It *was* in the context of idle and on up.

Here's part of the dialogue from that thread

: Me: "A regulator cannot force an alternator to put out full regulated voltage if the alternator is not turning fast enough - often the case at idle on vehicles with typical loads turned on."

(see how I was talking about real world cars at idle)

Your response: "False. Voltage will be at whatever the VR sets it to be, regardless of RPM. CURRENT on the other hand, may vary due to load and RPM."

There are at least two problems with what you said: (1) It disagrees with the inarguable fact that the voltage in many cars will drop a little at idle as the engineers designed the alternator speed at the edge of its capability to produce the voltage that the regulator is demanding for the idle speed and nominal loads. (2) You say that voltage will not vary with rpm, yet current will. A denial of Ohm's law.

Another place in the same thread, you said: "Revving the engine will do NOTHING to increase alternator output voltage; amperage maybe a little."

Again - an ignorance/denial of the laws of physics (primarily and fundamentally Ohm's law). You made a real world observation but failed to make the real world connection to the laws of physics that control the real world (see next paragraph).

Some of you guys seem to think that laws of physics are an inconvenience that get in the way of understanding real world observations. For one, if you had an understanding of the theory, the first time you caught your brain thinking: "I didn't vary the electrical load - I know voltage was constant - the regulator will ensure that. Yet, I saw the ammeter change when I rev'ed the engine. Hmmm - constant load, constant voltage, yet current changed - that seems to violate Ohm's law - which I know to be true. I better check this out!" So you get your voltmeter out and discover that - "...lo and behold - the voltage actually does increase a little when I rev the engine above idle. Well what'd'ya know

- it doesn't' violate Ohm's law - Ohm's law said that if the load is constant and the current changes, the voltage must be changing too. I guess my assumption that the voltage will be fully regulated even at idle speeds was incorrect". So you see how knowing the theory helped you fine tune your erroneous real world understanding (I mean the generic 'you' in that sentence - you probably still won't see it, and will resent my even illustrating this absolute truth to you).

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

OK - so some of these guys maybe have the valid excuse that they didn''t have the educational opportunities. You, on the other hand, apparently had the means to learn and better yourself, but, thru laziness or having everything handed to you or whatever, chose not to cure the gross ignorance that you have displayed.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Not even close...

but I still HIGHLY

Actually I think there is some good evidence that the DC electronic transmission family does have an inefficiency issue compared to others. I haven't ever really researched it hard, but here's my hunch about why its a bit on the lossy side:

Like all automatic transmissions, its gears are in constant mesh so in various different drive ratios (by which I mean "first gear" versus "4th gear" etc.) some of the whirly bits are spinning at various speeds but aren't actually in use. All automatics do that... but what all automatics *don't* do that the A-604 derivatives do is have multi-plate clutches that are released but the drive and driven plates are spinning at different speeds while in cruising gear. I think the shearing of the fluid due to the driving and driven plates spinning at different speeds is a loss mechanism that other transmission designs (for example, the old rear-drive Torqueflites in both 3-speed and 4-speed models) do not have. In high gear with an A-904 or A-727, both of the multi-plate clutches are engaged and the whole gear-train is locked into what amounts to a solid shaft, and only the bands are released. Bands don't exert a lot of shear force on fluid when released- multi-plate clutches do. In the case of the 4-speed versions (A500 and A518) the O/D clutch is released in 3rd gear, but in 4th its locked and the gears in the OD unit are working, but the main transmission section is still locked into a solid shaft.

OR, I chose to keep it all simple for you to understand, since most MEs I know, cant understand the simple fact that two objects, can not occupy the same space at the same time.

OR....

I just wanted to see how easy it was to pull someones strings that was trying to show the world how educated he wasnt...worked well.

Oh....BTW...through laz..what? Im sorry, I cant even begin to spell the word.....lazy you say? Sure man..whatever. Already proved that we knew what direction this would take, and how to get it there...you just were not involved in that conversation...

Never know when you are getting played...so continue at will.