What does a recent car really cost

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Flytox
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by Flytox » 14/01/08, 23:47

Bonjour à tous

Even in current "mechanics" let alone electronics, there is also a nice con. On Nissan (Primera) for example, there was a period where they focused on the 3 year unlimited mileage warranty ..... this warranty does not include wearing parts .... what are the timing belt ('normal'?) but also the toothed gears which are associated ....: Shock: : Evil:

To keep the guarantee, it is mandatory to change the pinions in question to (60 or 000 km?) And given the price of the parts (80 F 000 or 6000 years ago) for pinions that look new. .. this means that the guarantee is paid twice by the customer and at a gold price. :frown:

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by Remundo » 15/01/08, 10:52

Hello André,

On my motor mower : Cheesy: , I'm with a piece of rusty pipe, not flush with the manifold.

Andre wrote:Free exhaust to the collector flush you are losing power is yielding
depending on the speed and appropriate lengths of conduit per cylinder group there is a significant gain to be made
if you add a conscientious you will never arrive at the exhaust gain granted.
with a silencer the agreement is generally different, shorter leads (hence often a jar of relaxation)
For exemple
21kw free exhaust without tubing
with a free exhaust manifold 1,5m long 22kw
0,5 m tubing with 21,5 kW muffler
1,5 m tubing with 18,7 kW silencer


Acoustic impedances are never adapted at the end of the pipe anyway since the outside air is like a pipe of infinite section. There is therefore a return sound wave whose overpressure tends to hinder the evacuation of gases. We can nevertheless look for acoustic resonances according to the number of cylinders to limit the phenomenon, as you point out.

Your orders of magnitude in power are very interesting, and I am even surprised by their precision. Are these measurements or calculations?

The best solution is the free exhaust manifold, precisely what the kids do with their mob to break our ears. (22 kW).

I think the bulk of the loss comes from fluid rolling much more than return sound wave issues. Now "I could be wrong" :P .

The muffler + tubing leaves only 19 kW, a loss of 3 kW, which out of 21 is 1/7, or a trifle of 14%.

If we refer to your figures, my estimate of 10% loss was very optimistic ... especially that the FAP or the catalytic converter are real plugs next to a tube ...

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Philippe Schutt
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by Philippe Schutt » 15/01/08, 11:21

to come back to diesel fuel, I wonder if it would not be valid to put one, precisely. this would give a little fuel, perfectly vaporized and homogeneous, but in insufficient quantity to explode under compression. then a little injection would ignite it all.
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by Remundo » 15/01/08, 11:32

Diesel powered?

OK for your idea, but that disadvantages the filling of the cylinder, because the vaporized fuel takes a little place of air. When you have a Diesel, it is better to suck up a maximum of air, and balance all the fuel at the end of compression, so intense that the ignition is guaranteed, without the need to pre-inject.

Furthermore, I think that diesel is not volatile enough to pre-inject it in the form of an aerosol ...

Now, modern research tends to converge gasoline and Diesel. Mercedes is very advanced with its "Diesotto", that is to say an engine, roughly of the high pressure direct injection type, convertible at will to gasoline or diesel. The gasoline would work by auto-ignition according to an HCCI (homogenous charge compression ignition) design.

Well, maybe it’s not quite ready yet :?

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Chatham
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by Chatham » 15/01/08, 11:50

Remundo wrote:Diesel powered?

OK for your idea, but that disadvantages the filling of the cylinder, because the vaporized fuel takes a little place of air.
Now, modern research tends to converge gasoline and Diesel. Mercedes is very advanced with its "Diesotto", that is to say an engine, roughly of the high pressure direct injection type, convertible at will to gasoline or diesel. The gasoline would work by auto-ignition according to an HCCI (homogenous charge compression ignition) design.



A fuel requires a restriction (venturi) to operate, therefore: pressure drop which is counterproductive ... more vaporization in a fuel is poor in comparison with a high pressure injection type HDI which I remember that it works in multiple micro injections (up to 5 per cycle).
The Diesotto is a gasoline engine with direct injection and variable pressure supercharging which can, at low load only, operate in self-ignition ... As it is a gas plant whose slightest malfunction causes the explosion of the gasoline. engine or operation in "detonation" mode, I do not see that in large series for now ... : Mrgreen:
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by Remundo » 15/01/08, 11:59

I completely share your point of view on all your message.

We feel the specialist from Bo ... who is sleeping in you : Mrgreen:
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by Targol » 15/01/08, 14:03

To come back a little to the subject of electronics in cars:

Remundo wrote:He connects their mess like a USB key and concludes after 10 minutes that it is necessary to change "the whole box" and that another even more competent specialist is needed to reset the system. : Lol:


And again, you're talking about relatively new cars.
If you take the first generations of "suitcase" cars, sometimes the dealership doesn't have the suitcase in question (it happened to a friend of mine with a Ford from the 90s).
Result: impossible to repair alone because no access to electronics and impossible to have repaired in the garage because the brands organize the obsolescence of models by swinging the "old" diag suitcases. : Evil:

Otherwise, for "drive by wire" (replacement of mechanical parts by electrical signals), this is already the case in most recent cars for acceleration where the cable has been replaced by a knob.
The heavy argument of the manufacturers to justify this is the weight gain.
When the steering and braking have joined the acceleration in the multiplexed signals, the next step will be to replace the pedals and the steering wheel with a joystick: right / left to turn, forward to accelerate, back to brake.
We can already find the outline of this in certain arrangements for hemiplegics.
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by Philippe Schutt » 15/01/08, 15:58

Remundo wrote:OK for your idea, but that disadvantages the filling of the cylinder, because the vaporized fuel takes up a bit of air
the vaporization lowers the T ° of the air, from where a larger quantity admitted, which compensates. Above all, this remains unimportant, almost all diesels have a turbo which does much more than compensate for this slight pressure drop.
Remundo wrote:When you have a Diesel, it is better to suck up a maximum of air, and balance all the fuel at the end of compression, so intense that the ignition is guaranteed, without the need to pre-inject.
that's what we do, with the disadvantage of an area that is too rich and the rest too poor. the goal is to reduce this gap.
Chatham wrote:vaporization in a fuel is shabby in comparison with a high pressure injection type HDI which I remind that it works in multiple micro injections (up to 5 per cycle).
yes, in return, the droplets have time to vaporize, and the distribution in the air volume is more homogeneous. the 5 micro-injections are always in the same place.
Remundo wrote:Furthermore, I think that diesel is not volatile enough to pre-inject it in the form of an aerosol ...
this is what we do in boilers, even if it means preheating it a little.
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by Chatham » 15/01/08, 15:59

Targol wrote:
If you take the first generations of "suitcase" cars, it happens that the dealer no longer has the suitcase in question.

Otherwise, for "drive by wire" (replacement of mechanical parts by electrical signals), this is already the case in most recent cars for acceleration where the cable has been replaced by a knob.
The heavy argument of the manufacturers to justify this is the weight gain.


Indeed, if one has for example a DS or SM with Bosch D-Jectronic electronic injection (released in 1967), only the few rare specialists have the diagnostic case (hey yes already!)
If you go to the dealership:
A DS? are you sure it's a Citroën? ...
Cars are considered by manufacturers as "disposable" supposed to be "recycled" after 10 years ... : Cheesy:
The electric accelerator is often linked to another function such as anti skid or automatic or robotised gearbox, but not always ... For the weight saving: blah, if we count the additional box and the servo motor it m would be surprised that it is lighter than 50cm of simple cable under sheath (because at Renault for example there is all the same a small cable of ~ 30cm which comes on the knob on diesel) ...
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by Remundo » 15/01/08, 18:22

Targol wrote:Result: impossible to repair alone because no access to electronics and impossible to have repaired in the garage because the brands organize the obsolescence of models by swinging the "old" diag suitcases. : Evil:

When the steering and braking have joined the acceleration in the multiplexed signals, the next step will be to replace the pedals and the steering wheel with a joystick: right / left to turn, forward to accelerate, back to brake.
We can already find the outline of this in certain arrangements for hemiplegics.


Well for sure, like the PC manufacturers who do not make drivers for the old windows versions, like that everyone fucks vista who eats 1000 MB of ram to play solitaire ...

For the weight, you speak of an excuse ... If the cars are heavier and heavier, it is because of the safety reinforcements and the 50 or 100 kg of electric cable !! How much does a steel cable 2 m long and 2 mm in diameter weigh? Jokers these builders : Lol:

I am very open to new technologies when they are reliable and justified. Also, I want a steering column and cables and rods for my pedals ... and I don't want to be strolled with europhage diagnostic USB suitcases : Evil:
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