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Normal Operating Sounds

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Re: Normal Operating Sounds

#201

Post by xg15 »

joshspankit wrote: post #144
xg15 wrote: post #136

Earlier quoted context omitted.

I find it interesting that you can find stuff like this even in biology: When you shiver in cold weather, your body is basically doing the same.

This is an aside, but as a native of winter cold: shivering is an excellent strategy to avoid death, but it’s a terrible strategy for actually feeling warm. (Better is moving, relaxing, and massaging the ears/hands/feet to promote blood flow.)

Sort of makes sense to me. From what I understood from the wiki [1], you can compare the temperature regulation (very) roughly to a thermostat: There is a "target" temperature that the body "wants" to reach and a "current" temperature that the body senses it currently has.

If "current" is higher than "target", the body invokes several mechanisms to bring the temperature down, such as turning up sweat production and making you feel hot; if "current" is lower than "target", it does the same to raise the temperature e.g. by shivering and making you feel cold.

(Fever also works by changing the target temperature of that regulation system, which is why you feel cold at the beginning when the target was raised to the fever temperature and hot at the end when it was lowered back to the normal body temperature)

So it makes sense to me that shivering doesn't make you feel warm, because both, the feeling and the shivering are efforts by the body to raise the temperature.

[1] https://en.m.wikipedia.org/wiki/Thermoregulation_in_humans

Re: Normal Operating Sounds

#202

Post by annoyingnoob »

jowea wrote: post #185
londons_explore wrote: post #143

If I was the engineering team, I would be trying to eliminate all these noises. Every single one of these could be engineered away. For example the pops and bangs at a supercharger is the metal shield deforming when heated. Instead, it should have circular ridges stamped into it around the fixing points to let it expand against the springiness of the steel. The clunk noise from brakes could be engineered away by usin…

Don't you think customers want the audio feedback that everything is working fine?

The brake pedal does not have to make noise for me to know the brakes are working. The pads do not have to clunk. There does not need to be a thunk to the contacts opening on the battery when I park for me to know the car is parked. There is a difference between convenience acknowledgements and mechanical parts being clunky, they are all put together here.

Kind of shows where Tesla put its focus, and that there is work to do on future models. People used to higher end cars tend to notice and maybe not like the extra clunky bits, everything should just work smoothly and quietly.

Re: Normal Operating Sounds

#203

Post by flutas »

Kirby64 wrote: post #22
jacquesm wrote: post #17

Earlier quoted context omitted.

What is the cause? Thermal expansion? I have a room in my attic that can make really loud bangs on hot summer nights (enough to scare the crap out of me when I am concentrating on something and do not expect them) when it contracts again after a day in the heat. The root cause there is stick slip: the thing doesn't move for a long time due to its weight so tension builds up and then suddenly it will shift a little an…

Similar mechanism as your attic noises. There's a giant metal plate on the bottom of the thing, so all the heat generated while it's supercharging (in a very cold environment) causes that 'snap' which makes a loud noise. Same thing happens if you've ever heated up a thin metal baking sheet. It'll 'snap' from one position to another and make a horrible racket. Same thing apparently happens if you are heavy on regenera…

Something else interesting when supercharging in the cold...LOTS of steam(?) at times.

Shocked me the first time it happened. Cold (~5F outside), low and hot battery (just went from 80 to ~5%). Legit thought the car was on fire at first.

Re: Normal Operating Sounds

#204

Post by hedora »

londons_explore wrote: post #143

If I was the engineering team, I would be trying to eliminate all these noises. Every single one of these could be engineered away. For example the pops and bangs at a supercharger is the metal shield deforming when heated. Instead, it should have circular ridges stamped into it around the fixing points to let it expand against the springiness of the steel. The clunk noise from brakes could be engineered away by usin…

The government-mandated “safety” tone that EV’s play at low speed was invented by a marketing department. They wanted to be able to force everyone to play their audio logos.

Fast-forward a decade, and the bought-off regulators left for industry. The remaining transportation safety people in the US realized the tones are useless, since the sounds are not standardized and are therefore ambiguous and ignorable.

So, moving forward, they’ll standardize the noise, defeating its only practical purpose (branding). Sadly, they didn’t revisit whether it was actually necessary or helpful in the first place.

Our pre-tone EV makes plenty of noise at low speed due to various servos, capacitor whine, drivetrain gears/friction, and so on.

Re: Normal Operating Sounds

#205

Post by rootusrootus »

op00to wrote: post #141
bb123 wrote: post #100

Earlier quoted context omitted.

This is due to a phenomenon called heat soak which is where the engine temperature increases above normal for a time after it has been switched off due to the lack of coolant flow. The fan is coming on to aid cooling the engine/engine bay to reduce the effect of heat soak. With carburettor fed engines it is sometimes advised by the manufacturer to allow the engine to idle for some time after running it at high RPM. T…

I had an old Volvo that would “vapor lock” on short trips. It’s amazing how reliable cars are now compared to 20 years ago.

In my experience it was more than 20 years ago that this happened. It was when most cars switched to fuel injection. Late 80s, early 90s. Treating a car as an appliance and having it 'just work' became so much easier when fuel injection was invented.

20 years ago was 2003, which is practically yesterday [in my mind...].

Re: Normal Operating Sounds

#206

Post by 93po »

newaccount74 wrote: post #87
freediver wrote: post #48

Earlier quoted context omitted.

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.

Tesla cars, including the Cybertruck, are much less likely to run over things, including kids, than most every other vehicle. There are distance sensors around the entire perimeter of the car that give you a visual and audio queue for when you're close to stuff, and there's cameras that also cover 360 degrees that show pedestrians and other obstacles on the navigation screen.

The people at Tesla have a lot of fun even with the Cybertruck: why aren't the windows also bullet proof to small arms? Well, because it'd have to be really thick, and we recommend instead that you simply duck when shot at.

Re: Normal Operating Sounds

#207

Post by ComplexSystems »

rijx wrote: post #163
londons_explore wrote: post #143

If I was the engineering team, I would be trying to eliminate all these noises. Every single one of these could be engineered away. For example the pops and bangs at a supercharger is the metal shield deforming when heated. Instead, it should have circular ridges stamped into it around the fixing points to let it expand against the springiness of the steel. The clunk noise from brakes could be engineered away by usin…

Would you have delayed the first release to tackle these sounds? If so, any day not shipping products is a day closer to going bankrupt. If you "fix" these sounds in v2, then you'll still need to explain them in the manual for v1 owners. Ultimately it's not really a bug. People aren't used to cars being so quiet so some minor new sounds suddenly stand out.

Do you think it took less than a day to implement "ludicrous" mode?

Re: Normal Operating Sounds

#208

Post by rootusrootus »

rainbowzootsuit wrote: post #197
actionfromafar wrote: post #139

Earlier quoted context omitted.

Also turbo charged engines can greatly benefit from running idle for a minute. I learned the hard way. (Had to replace the turbo.)

There have existed "turbo timers" that keep the engine running for a short time after the key is off to help avoid this. Not sure if that works with modern cars as easily.

Modern turbo designs (most anything in the last 25 years, at least) use water cooled turbos and convection keeps the water flowing after the engine is turned off. This is why we don't use turbo timers any more.

Re: Normal Operating Sounds

#209

Post by 93po »

AYBABTME wrote: post #14

The loud "pops" at superchargers and when driving after supercharging surprised me for a while. I would stop to look under the car if I had hit something. The pops while charging are sort of self-explanatory, but those while driving took me a while to associate back to the prior supercharging. Basically, changes in temperatures are causing the pops. It's kind of weird and slightly annoying. Sometimes it happens for q…

I've never heard these pops but I've also never supercharged in the cold

Re: Normal Operating Sounds

#210

Post by rootusrootus »

c0nsumer wrote: post #194
spike021 wrote: post #41

Earlier quoted context omitted.

I have a relatively analogue car (Subaru BRZ) and there are times when you shut it off on a warm day and then randomly about ten mins later a radiator fan kicks on. I guess it's to help cool down but I don't remember exactly what the manual says. Basically it's cool how cars do things largely on their own sometimes to stay within certain parameters.

Because it was designed with Toyota I don't know if the BRZ does it, but a number of other Subarus will kick on an recovery pump ~6 hours after ignition. It sounds sort of like a small/quiet compressor. Before I looked up what it was, I kept hearing a gentle noise coming from the garage in the late evening. Figured it was noise from outside... Then one day I was out there and heard it start, realized it was the car,…

That is the evap leak testing pump. It pressurizes the tank briefly to test the effectiveness of the cap.
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