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Normal Operating Sounds

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Re: Normal Operating Sounds

#81

Post by semi-extrinsic »

sbierwagen wrote: post #50
jacquesm wrote: post #16

Earlier quoted context omitted.

A gasoline based ICE is so incredibly inefficient it needs to shed heat or it would melt down. It makes more heat than that it makes motive power (the thing it is designed to do...). A 50 KW engine makes 200 KW(!!) of heat (at full throttle). Most of that heat energy exits the system through the exhaust gases but there is plenty that gets stuck in the body of the engine and you need to remove it from there somehow be…

>Some diesels got so efficient though that they needed an extra in-line heater to have enough heat for the cabin in specific operating domains I live on the top of a hill, so the first seven minutes or so of me driving anywhere is coasting at minimum engine power. Once air temp gets below 10C it's a long, slow painful wait for the vents to start blowing warm air. Especially unfortunate when you're waiting for the def…

Better than (or in addition to) a block heater is to have an AC cabin heater. Defa makes some really nice stuff, it's more or less "standard extra equipment" here in Scandinavia.

Re: Normal Operating Sounds

#82

Post by JasonSage »

sgc wrote: post #69
throwawaaarrgh wrote: post #60

Earlier quoted context omitted.

The fan is triggered by a relay, triggered by the ECU, which uses coolant sensors (the thermostat sensor that is iirc not always the mechanical thermostat) to adjust when to cool the radiator. That temp is much higher than the ambient air will ever get, so if the fan comes on after the car is turned off then either it was just about at the temp that would have turned on the fan, or something could be slowly going wro…

Car engines heat up when you park, because the air cooling and circulation of the coolant keeps it cooler while driving. It seems completely within the common laws of physics that when you are at not so uncommon temperatures, the coolant closer to the engine heats up well above standard operating temperatures once the car is off, and then convection currents bring enough of this overheated coolant to the sensor to tr…

This is 100% correct.

For those curious, the coolant around the engine block can boil and flow upwards after the engine is off, and the coolant circulation system is designed to handle this pattern. You can observe this yourself if you overfill your coolant and take it out on a hot day, the excess hot coolant will bubble up and run out for a good while after the engine is off.

I second the advice that if the engine isn’t overheating while running, everything is likely working as intended.

Re: Normal Operating Sounds

#83

Post by josephcsible »

wardedVibe wrote: post #80
josephcsible wrote: post #71

Earlier quoted context omitted.

How can anything be <100% if producing heat is the goal? Where would the rest of the energy be going?

They mean a heat pump. You apply work to transfer heat, getting more inside than if you had just turned the energy into heat directly; the outside gets colder of course. https://en.wikipedia.org/wiki/Heat_pump#Principle_of_operati...

Yes, heat pumps are over 100%, but isn't turning the energy into heat directly exactly 100%?

Re: Normal Operating Sounds

#85

Post by sweetjuly »

josephcsible wrote: post #51
otteromkram wrote: post #42

Earlier quoted context omitted.

I hope legislation gets enacted that will make it illegal to blast artificial "exhaust" noises from EVs. Not like cops will actually enforce it, but one can still dream...

No need to make it illegal. The laws just need to be fixed to stop making it mandatory, and every automaker will drop it immediately.

The mandatory noise maker is an important pedestrian safety feature. It helps you avoid getting hit by cars. It's also only required at low speeds (and at higher speeds it wouldn't matter anyways due to tire noise dominating).

Re: Normal Operating Sounds

#86

Post by vachina »

freediver wrote: post #48
camhart wrote: post #2

> Cabin Noise during Acceleration with Ludicrous Enabled This one is pretty good.

Props to the person/team owning docs at Tesla. This made Tesla as a brand more humane in my book.

Thought the car would actually play that sound effect on Ludicrous mode.

Re: Normal Operating Sounds

#87

Post by newaccount74 »

freediver wrote: post #48
camhart wrote: post #2

> Cabin Noise during Acceleration with Ludicrous Enabled This one is pretty good.

Props to the person/team owning docs at Tesla. This made Tesla as a brand more humane in my book.

This is the kinda good natured fun that I really liked Tesla for before they announced an armored vehicle that's designed in a way to increase the likelihood of accidentally running over your kids playing in the driveway.

Re: Normal Operating Sounds

#89

Post by stephen_g »

josephcsible wrote: post #71
Rebelgecko wrote: post #56

Earlier quoted context omitted.

Actual heating systems can be better than 100% efficient, while crypto mining or cinebench or whatever is <100%

How can anything be <100% if producing heat is the goal? Where would the rest of the energy be going?

I’m not sure what they mean about crypto miners or computers (mentioning cinebench), basically all the energy going in should be turned into heat so that should be near enough to 100% efficient. Where else would the energy be going? Sure, there will be a bit of RF power (Wi-Fi and some EMI) and depending on the device, a bit of light (LED indicators, monitor backlight) but that should be tiny compared to the energy that will end up as heat…

In terms of heating systems though, it’s normal for fuel based systems to be <100% because you need to vent exhaust, and a lot of your heat your fuel produced can be rejected away from where you want it with that. For example, older gas boilers might only be 80% efficient or so, and even the much more efficient condensing boilers are still only in the low 90s.

Re: Normal Operating Sounds

#90

Post by stephen_g »

vGPU wrote: post #72
koverda wrote: post #62

Earlier quoted context omitted.

what do you mean?

Heat pumps can provide an “efficiency” of some 300-400%+. The “trick” is that they use electricity to move heat instead of creating heat, which is why heat pumps stop working well under a certain temperature. They kinda work like a reverse refrigerator. A fridge takes heat out from the inside and moves it to the outside. A heat pump does the opposite.

You’ve completely failed to answer their actual question, it was the claim of less than 100% efficient heating they were asking about…
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