• grue@lemmy.world
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    10 months ago

    My favorite part about that story is how the US built a fighter that could actually do everything needed to counter what we thought the Soviet plane could do. It was a massive flex that happened by accident.

  • kersploosh@sh.itjust.works
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    10 months ago

    As a kid I couldn’t decide whether the F-14 or F-15 was the most fucking awesome thing in existence. I mean, just look at them! Those planes are what sexy feels like before you’re old enough to know what sexy even means.

    • neidu2@feddit.nlM
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      10 months ago

      To me it was F14. F15 is cool and all, but… I definitely saw Top Gun while way too young.

      • Enk1@lemmy.world
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        10 months ago

        I mean, even without watching Top Gun the retractable wings were the coolest thing ever for a kid. It was the aviation equivalent of Mad Max flipping on the supercharger on the V8 Interceptor.

        (I know, I know. You can’t actually spin up a supercharger like that, but it’s still fuckin cool.)

        • grue@lemmy.world
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          10 months ago

          (I know, I know. You can’t actually spin up a supercharger like that, but it’s still fuckin cool.)

          Technically you could design a supercharger with a clutch (like the one for the car’s A/C compressor) , but it’d be dumb because there’s no good reason not to have it active all the time.

          • nBodyProblem@lemmy.world
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            10 months ago

            Superchargers come with massive parasitic losses, in many cases 10-20%, and there’s a decent handful of cars with clutches on the supercharger pulley. The MR2 is one.

          • Socsa@sh.itjust.works
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            10 months ago

            Not running the extra 20kg or whatever of rotating blower mass would increase efficiency for cruising. A supercharger doesn’t have a good way of doing active bypass when you don’t need boost like a turbo wastegate so just turning it off can save some mpgs.

            • grue@lemmy.world
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              10 months ago

              If the size of the turbo on my VW is anything to go by, I think the rotating mas of an automotive supercharger would be more likely on the order of 2 kg, not 20 kg. In my mind, that has two implications: (a) the gain from bothering to disable it is perhaps not actually all that significant, and (b) the additional mass that would come with attaching a clutch to it might be large compared to the total mass you’re trying to control, so maybe it wouldn’t be worth it. Then again, the Previa supercharger the other reply gave (which certainly wouldn’t be a very large supercharger) might be a counterexample…

              • SomeoneSomewhere@lemmy.nz
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                10 months ago

                Turbos spin far faster than (Roots-type) superchargers, and can therefore be much smaller.

                Besides that, I don’t think rotating mass is really the issue. Yes, more inertia is like having a bigger flywheel so the engine will be slower to spin up/down, but that doesn’t consume much energy, especially in steady-state cruising.

                Superchargers compress air - that takes energy. You then restrict it through the throttle body, because you’re not cruising with a wide-open throttle. That throws away all the compression.

                You also have pumping losses and bearing/gear/belt losses.

            • Enk1@lemmy.world
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              10 months ago

              With a Roots style supercharger like the 8-71 on Mad Max’s, if the supercharger isn’t spinning then there’s no path for air to enter the engine. You’d have to implement another full-size throttle body as a bypass to allow enough airflow into the engine when the supercharger isn’t rotating. SCs are very parasitic, hence their use mostly being limited to larger displacement engines that have sufficient low-end torque offset the draw. You could definitely resolve this with a clutched pulley and a bypass throttle-body, the complexity, space requirements, and engineering needed to make it work isn’t worth it. Multi-sized sequential triple turbos are clearly the superior solution to boost at any RPM.

            • grue@lemmy.world
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              10 months ago

              This kind of makes me want a Previa. And not for the first time, either: it’s a thought I have at least once a year or so. Maybe I should finally act on it.

              The main reason, aside from the fact that I actually kinda like minivans, is that I want to be able to tell people I drive a manual-transmission, supercharged, mid-engine, AWD car. And then after they try to guess what kind of Italian supercar it is, I can say “Nope! It’s an old Toyota minivan! 🤪”

              It’s just unfortunate that AFAIK you can’t get all three of those features (manual, supercharger, AWD) on any single Previa – the trim levels were arranged such that they only ever came with at most two of the three. So I’d have to get a automatic '97 S/C AWD and then do a transmission swap on it.

          • Enk1@lemmy.world
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            10 months ago

            I definitely haven’t spent countless hours thinking about how you could have a mechanically activated clutch on a supercharger pulley. Nope. Not at all.

        • this_1_is_mine@lemmy.world
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          10 months ago

          Funny story. Nowadays you could feaseably run a dual forced air like turbo and super charging and use an electric clutch to disengage the super. But the intake would be convoluted with some way to bypass the stupid charger or the turbo depending on rpm. it just makes it not worth it.

          • Bananigans@lemmings.world
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            10 months ago

            In real life conversation I’d laugh and pretend I understood that. I’m glad the internet makes ignorance more comfortable.

            • Enk1@lemmy.world
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              10 months ago

              Imagine you’re breathing through a big straw, and at the other end of the straw is a device that pumps air faster whenever you’re breathing faster, say when you’re running fast. If you turn off power to the pump, you can’t breathe through the straw anymore because the pump isn’t spinning, so you’d need a second straw that opens up only when the pump is off.

              You are the engine, and the pump is the supercharger. When the engine doesn’t need to breathe fast, turning off the supercharger would conserve energy use at the expense of power output. But the design of the pump doesn’t let air bypass it when it’s off, so you’d need to engineer something (overly complex) to do it.

      • kersploosh@sh.itjust.works
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        10 months ago

        I’m told that I first learned to swear by watching Top Gun with my older siblings. Dad was impressed that I even used the words correctly in context. Mom was not happy at all.

    • southsamurai@sh.itjust.works
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      10 months ago

      I mean, if you ignore the f4, the f14/15 are the sexiest aircraft ever. But, c’mon, the f4? That’s jizzing pants territory.

  • Thomas@discuss.tchncs.de
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    10 months ago

    I guess this refers to MiG-24 vs. F-15. Wikipedia writes:

    The appearance of the MiG-25 sparked serious concern in the West and prompted dramatic increases in performance requirements for the McDonnell Douglas F-15 Eagle, then under development in the late 1960s. The capabilities of the MiG-25 were better understood by the West in 1976 when Soviet pilot Viktor Belenko defected in a MiG-25 to the United States via Japan. It turned out that the aircraft’s weight necessitated its large wings.

    https://en.m.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-25

  • Pxtl
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    10 months ago

    From the title I assumed it was going to be about the F-104 Starfighter AKA Widowmaker AKA Lawn Dart AKA Aluminium Death Tube.

    • neidu2@feddit.nlM
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      10 months ago

      My understanding is that the 104 was great at the tasks for which it was designed. Unfortunately those tasks no longer exist, and the auxiliary tasks is where it was truly horrible. Tasks that may not be the primary role, but are still critical to the operation. You know, such as landing, slow flight, maneuvering, etc.

      • neidu2@feddit.nlM
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        10 months ago

        I concur. Missing half of the wing area never looked better. X15 is a close 2nd.

  • hglman@lemmy.ml
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    10 months ago

    You know or that was all a tactic of the military-industrial complex to justify its projects.