Popular Mechanics (for years one of the worst ways to spend a few bucks on a magazine) must have some new management. There are actually some articles that are worth reading , rather than the magazine just being a buyers look at new products.
Anyway, they did dyno testing in Houston on several of the 'wonder' products including the ubiquitous magnetic devices, the Tornado apple corer and fuel saver, vapor induction, etc and as we all might have suspected, none of these idiots delights did anything positive. Total waste of money.
Maybe if we urged them, they would actually test oil and air filters and give a more or less scientific opinion.
Could you please tell us the issue, volume, page number and some more info on the 'Popular Mechanics' (ISSN would be nice too) about where to find that article?
You should've been over on rec.autos.makers.chrysler early last week. Some ignorant dipshit calling himself "Whoever" was arguing that restricted air filters don't reduce fuel economy. He dug himself a hole most of the way to China, making all kinds of hilarious claims regarding having formerly designed EFI system, talking about how the O2 sensor controls the fuel injectors' pulsewidth during open-loop operation, etc.
I don't know if there's a joke hidden in your statement, :) but yeah, I replied to him as well. I tried to explain what I think he was missing in his argument. Maybe he worked for Ford in their EEC III division.
My favorite poster this week "*" interjected incorrect info into a P/S system discussion, then said that so many people in NGs don't know what they are talking about that he now choses to 'mess with them' 'cause it's fun.
I liked the engine fire they had because of the B&G Ionizer. Looking at the picture it appears to be some cheap wire with wire nuts every few inches covered with plastic dip coating. Did you notice the HP drop on just about every device as well. That Fuel atomizer looks neat, kind of like a small still attached to the engine....And the Aqua Tune hype "Aqua Tune is like no other water injection system in that it is, in actuality, a fuel cell hydrogen processor> It produces hydrogen rich bubbles before being introduced into the engine draft" I have to agree with PM when they ask anyone to explain how it works.
Hundred percent agree. Many scam artists in a lot of fields use enough scientific buzzwords to impress and amaze the uneducated. There ought to be a law...
Sounds feasible to me.. . The engine management system wouldn't know the difference between an iccompletely-opened throttle and a clogged aire filter. Less incoming air mass =3D less fuel injected to achieve the optimum results at the O2 sensors. =20 I don't think it would save much fuel though, since the same amount of energy would have to be created to accelerate and maintain speed. At less than WOT, the driver would simply depress the pedal a bit more to compensate. =20
More likely: The system would throw a fault because the air mass wouldn't match what was expected for the throttle position. =20
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I read you original "discussions" and then did some more research.=20 Neither the TPM or the MAF have full control over fuel flow. Although, per this article:
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TPS has less influence than the MAF..=20I suspect this may vary between systems..=20-- Email reply: please remove one letter from each side of "@" Spammers are Scammers. Exterminate them.
One of the biggest myths uses the fact that only about 1/3 of the energy in the fuel goes into producing useful work propelling the car. There is a false believe that this means only 1/3 of the fuel is burned- the rest goes out the tailpipe as raw gasoline. This is, of course, not true- almost all the fuel is burned. Another part of the myth is that the fuel does not vaporize well. So many of the gadgets perport to help vaporize the fuel. Others claim to "energize" the fuel so that it burns more efficiently. Again, in modern engine the fuel burns fine enough- it is other, almost unavoidable losses that are the problem, and no easy solution to these problems exist. Only solutions- hard- are to greatly increase the operating temp of engine, and make long stroke, slow turning engines, which are big and heavy, and while a bit more fuel efficient, raise the horsepower-needed requirement (self-defeating, of course).
Increasing the efficiency of fuel burned is of course the goal. I did some calculations recently taking the thermal equivalent of mechanical horsepower, and relating it to heat content of gasoline per unit time. (I know that theory and practice here diverge a bit, but for a given horsepower generation there is a direct relationship to fuel burned per unit time)
One horsepower is 0.7547 kiloJoules per second. Heat energy to be derived from gasoline is about 50 kiloJoules per gram.
If you drive 70 miles in one hour, and use 1 gram per second, that is 3600 grams, or approximately one US gallon (hence 70 miles per gallon). Backing everything up, this would have generated 67 thermal horsepower at 100% conversion efficiency.
All things considered, to attain 25-30 mpg on some of todays cars is a pretty decent feat, considering the above ultimate limitations.
I describe sensor importance this way: MAF is the big dog, TPS input is very important, coolant temp very important though not a quick response input like the previous two, and the O2 sensor(s) provide feedback so the ECM can determine which output values to dictate by use of a programmed data table.
Indeed. Present auto engines considerably exceed the efficiency my old thermodynamics prof said was the maximum a car engine would ever reach. There is still a ways to go, but the easy fixes are already being used, and it will be pretty hard to go much higher.
If we can get very high speed feedback control of injection, I see the direct cylinder injection possibly allowing a bit higher CR in something like a pseudo-Diesel cycle.
Huh? I mean... was he talking about the maximum theoretical thermodynamic efficiency, or about how far up to that maximum the efficiency in his opinion would be able to go?
You may all remember that some 40-50 years ago, engineers calculated that a 'car' would never be able to exceed 140 mph in the quarter mile. So much for that.
I remember professors talking in terms of 25-35% efficiency for an IC engine, I believe.
As I mentioned in my original post, 'theory and practice tend to diverge'. Thermal efficiency (or thermodynamic efficiency) is probably still not so very great, but has probably improved since those days.
Transmissions, engines, etc combine to give reasonable speed and acceleration (with minimized losses) without usually coming anywhere close to the published maximum horsepower specifications (which are often bogus to begin with). I think this is the most significant factor behind the good mileage we get now.
Smoky Yunick worked on adiabatic engines as a consultant during his 'retirement' and made considerable headway. We are closer to being able to build such high temperature engines today than ever before. Lubricants can be made that will hold up near 200C, and metallurgy/ceramics can run in that range and much higher easily enough. To go significantly higher, organic lubricants may not be able to hold the mark....at least, not yet. Eutectic fluids might do it now.
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