this post was submitted on 20 Dec 2024
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Today I Learned

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I never knew and got curious and looked it up. I guess it makes more sense than slamming your testicals against the wall.

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[–] LovableSidekick@lemmy.world 23 points 1 day ago* (last edited 1 day ago) (2 children)

"Just under the wire" has a similar aviation lineage. According to my dad some WWII fighter planes had a wire attached across the throttle lever slot to mark the point that was considered "full throttle". The wire was breakable, so a pilot in a desperate situation could push the throttle farther forward if necessary, but I think there was a danger of blowing up the engine. So being just under the wire meant not quite past that point.

[–] pwnicholson@lemmy.world 27 points 1 day ago (1 children)

Cool story, but not where that comes from and not how that phrase is used.

"Just under the wire" means "just in time", "at the last second", etc.

It comes from horse racing and the wire they would strong across the finish line. Same as "down to the wire"

https://www.dictionary.com/browse/under--the--wire

[–] LovableSidekick@lemmy.world 5 points 12 hours ago

Interesting - I know about the horse-racing wire, it was to trip the photo-finish camera.

[–] EvacuateSoul@lemmy.world 16 points 1 day ago (4 children)

WEP, war emergency power. Depends on the aircraft how long you could use it.

https://en.m.wikipedia.org/wiki/War_emergency_power

[–] captain_aggravated@sh.itjust.works 5 points 14 hours ago (1 children)

The Corsair had water injection as a WEP, I forget by what mechanism it worked but it could make that big ol' Pratt & Whitney eat its own guts for more horsepower.

[–] Madison420@lemmy.world 6 points 13 hours ago

Water methanol injection, cools the air charge which makes it denser, more air you can cram in the more fuel you can cram in with it.

https://ww2aircraft.net/forum/threads/the-f4u-1-and-water-injection.40598/?amp=1

[–] LovableSidekick@lemmy.world 1 points 12 hours ago

Thanks, that's a lot more than my sketchy memory of what my dad told me (WWII pilot). Might not be where "under the wire" came from but it's fascinating.

[–] joulethief@discuss.tchncs.de 4 points 19 hours ago

Thanks for the read, that sent me down an interesting rabbit hole

[–] dave@feddit.uk 7 points 21 hours ago (2 children)

TIL you can increase engine power by mixing water into the fuel.

You can also increase speed by not using any propellers or moving parts. At supersonic speeds you capture the air, compress it into a chamber than hit it with a spark and blow the fucker up. That's how a ramjet engine works. China just made one that uses pulse like combustions in a engine that's only about a foot wide, and maybe 13 feet long. Speeds up to mach 4.. or 5000km/h (3100mph) at about 65,000 feet.

[–] Madison420@lemmy.world 3 points 13 hours ago

It needs to be injected into the air charge with the best atomization you can manage for best results.