Re: Simultaneous Application of Gas and Brake Pedals

I'd say it the other way around. Disk brakes need larger piston area because they don't have the self-energizing capability. :-)

Matt

I worked for a "corn binder" dealer in the early seventies, and my impression then and now, was "under engineered and over built". They were dirt simple, rock solid, butt ugly, almost indestructible, crude, purpose built machinery. They were elegent in their simplicity, and if the ultimate test of engineering is not that nothing more can be added, but rather that nothing more can be removed, then you could say they were well engineered.

But in so doing, as Nate has pointed out, other things are traded off and design safety margins (for pedal travel, pedal hi point, pedal low point, etc.) are more compromised.

And the larger caliper piston area multiplies the required pedal travel, but what saves the disc brakes from that effect is that the caliper/piston/pads relax (away from the rotor) a lot less than the shoes relax away from the drum when brakes are off, so that part turns out to be about a wash.

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

Because the non-boosted system is designed for the differences.

Fair enough.

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

For a sports car, that would be *under* engineered, for a truck expected to stand up to poor treatment, poor maintinence, poor fuel, etc.. and keep running and running I think that is a pretty good definition of what the target should be, IMHO.

Bernard

No, you will ask for an alternator to fit a sept 1994 production (or a an "N" code) Honda Civic SE, or whatever, and IF more than one manufacturer was used on that model and production date, the counterman will ask which one it is, as the alternator, or distributor, or starter or whatever is built by these several different companies SPECIFICALLY to HONDA specs. The mounting ear location may fit ONLY a certain Honda engine, and nothing else.

And for wheels, it is just as correct to refer to say, a 4 boltX 98mm

13X5" J3 rim with negative offset as to say it is a Fiat 128L rim. (numbets may be off a bit, but 4X98 it is. Or Chrysler 5X100mm, or GM 5X115, or Ford/AMC/Mopar 5X4.5?

DOes not matter what the original application was if it has the right bolt pattern, size, and offset.

There is ONE reason why disk brakes generally are more likely to require a booster, and it relates directly to increased pedal motion. Put simply, a disk brake caliper has a much larger piston than a wheel cyl, and therefore it takes more fluid to move the pads. To move that volume of fluid and produce the required pressure without excessive pedal travel on an undeslung pedal design is not impossible - but using a booster makes it significantly easier.

Not true, alternators may be used on BMW, or Volvo, or Volkswagon that are the same part number.

Distributor caps that fit a Subaru may also be found on a Toyota.

Don't take my word for it (since I have only been ASE certified P2 for ten freekin' years) open up a buyers guide for Standard,Niehoff, any tune up parts manufacterer. Then look in the back of a buyers guide for rotating electrical (alternators & starters) and see what the application listings are by part number.

A little knowledge.....

Bernard

I understand that.

I understand that.

I understand that.

Yes - frequently. Chevrolet wheel, Chrysler transmission, etc., etc., etc.

To hear you and Daniel, I get the impression that if someone posted a statement like "Hi guys. I hear that Chrysler transmissions of the early and mid 90's were trouble-prone" that you would be totally puzzled about what the person meant by "Chrysler transmissions", when everybody else would know exactly what was meant.

It's done all the time. Again, Chevrolet wheels, Chrysler transmissions, etc., etc., etc.

You missed it on this one.

I knew enough even as a teenager in the sixties to know that when a mecahnic told me that my Travelall had an AMC transmission in it that it had the same transmission that was used in AMC vehicles. Sounds pretty practical to me.

Oh - so other "classes" of people are immune from that. B.S.

So you're saying I should use pounds as a unit of torque? What's practical about that?

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

The stark reality just hit me that you took my comment about the reason for the difference in referencing types of wheels and alternators and transmissions being because wheels are round and alternators and transmissions are irregularly shaped as a serious assertion on my part.

LOL! Please tell me that isn't the case.

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

try this as an explination (lifted from the IH digest page)

Begin quote

Dana Fisher -- 1/10/2000, 3:33 p.m.

The T-409 automatic transmission is a heavy duty cast iron unit made by Borg-Warner. AMC called it a flash-o-matic. The T 39 and T 49 are the same just not as heavy duty in the servo and planetary area. This style goes way back to the 50's with IHC T26 T28. They got better over the years but were quite heavy and I think Warner quit making them in 1971 or there abouts--IH being about the only user. Ford also used this design but used linkage for the kick-down not electrical [ Ford Model FMX ]. I think Japan even copied it but shrunk the mold somewhat.

end quote

Made by borg warner, they are an independant company that makes MANY transmissions for MANY auto and truck manufacturers. Apparently it was also purchased by AMC, but was, in fact not an AMC trans. Small point perhaps, but laziness annoys some people.

Nope, just saying you seemed like a particularly bad type of nut-job that I had run into before.

See? that sentance makes absolutely NO sense.

>

Nope, just heard misinformation about stuff I do each and every day.

Examples of the misinformation would be...?

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

Yes - I know your type too, if you want to start stereotyping people - the guy, who for whatever reason did not get a college education, and stupidly feels inferior to those who did and so looks for reasons to cut those whom he feels inferior to down to try to feel better about himself.

I'm still amazed that all of this is over a simple statement that I was told that the vehicle I drove as a teenager had an "AMC transmission". While, for non-professional conversation, it was perfectly adequate for conveying what was meant, you are looking at it as an opportunity to nit-pic the precise meaning of. You don't really believe that you don't know what someone means when they say an early- or mid-90's Chrysler trasnmission? I suppose you have some convuluted explanation why that isn't the same as a statement of that day of saying the vehicle used an AMC transmission? Yes - I also know your type very well.

I was just trying to find examples of what you were nebulously claiming about impracticalities in what I had said previously that put me into your stereotypical view of engineers. The only thing I could find that you might have been referring to was the example I had given of technical illiterates who express torque values in pounds. You seem to fit the category. So how does it feel to be stereotyped? Are you one of those guys who tries to sell your customers SilverStar bulbs because they are "brighter".

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

But those were indeed CHRYSLER transmissions.

If you said, "I hear mid-70s AMC transmissions were trouble prone," I'd say, "Which do you mean? The GM-built Hydramatic in the full-size Jeep trucks, Cherokee, and Wagoneer, or the Chrysler-built TorqueCommand in the cars?"

Actually disks don't take more fluid because while drum brakes retract fully against their adjuster stops via springs, disk brakes only "retract" as far as rotor runout pushes them. So the volume of fluid that moves is typically less with disk brakes, which is why front disk/rear drum braking systems typically have a hold-off or pressure balance valve that prevents the disks from activating until some fluid has been pushed toward the rear drum brakes and the shoes actually begin to engage the drums.

I guess I chose a bad example then. But *IF* the Chrysler trannies were made by a third party, then people still would understand if the statement were made as I said it.

I think this horse is dead about three times over. Thanks for your sensible discussion on this.

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

But you adjust your drum brakes at every chassis lube interval... right? :)

nate

Yeah, that's the one I was thinking of - also used by Studebaker as the "Flightomatic" or "Powershift."

nate