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Thread: Porsche sets a new world record on the Nürburgring-Nordschleife

  1. #21
    "Shoe"
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    Quote Originally Posted by SteveLevin View Post
    Within the current rules, yes, And I'll be the first to admit that even if I got offered Corvette driver money there's no way I'd ride a bike with a massive turbo sitting between my legs.

    But for F1 engines there are definitely more efficient ways of generating power that would fit within the required packaging -- they just wouldn't be the spiffy multi-mode software driven hybrids of the current rules, which require entire software teams just to develop software so the "power units" don't tear themselves, the car, and quite possible half the neighborhood apart

    btw, did anyone catch a few races ago that the Renault engines have at least tested a trick self-starting mode? In one of the practice sessions Hulkenberg lost power, and they were feeding him instructions on a sequence to try and use the MGU-H to spin up the MGU-K and fire it back up. But they couldn't get it to lock on the transaxle's primary shaft (the one that connects to the power/input side) so the experiment failed.

    Steve
    Forget hybrids. We are talking about ICE engines. To take that a step further, how to you increase efficiency of an NA motor without RPM?

  2. #22
    Master of Disaster SteveLevin's Avatar
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    Quote Originally Posted by Stuntman View Post
    Forget hybrids. We are talking about ICE engines. To take that a step further, how to you increase efficiency of an NA motor without RPM?
    Lower rpm and greater displacement is always more efficient. You also want to go with the largest bore and shortest stroke you can get away with.

    Many moons ago BMW actually published a bunch of the engineering decisions behind the 'eta' series of petrol engines; I don't know if they can be found online all these years later but I got mine in 1988 at the factory museum.

    But some other key thoughts are:

    God loves the smoothest airflow into the combustion chamber possible. High RPM tends to be more disruptive because you are more or less "hustling" the air quickly into the cylinder.

    friction is expensive, just like ex-wives. So avoid both if you can.

    and high piston speeds require unobtanium wristpins and stuff so the Elvis the piston doesn't leave the building.

    I'm sorry if I'm not making perfect sense. this has been a galactically crappy week for me. The only thing I have managed to avoid was the ambulance ride, but to borrow from the original Lethal Weapon... "week ain't over yet"

    when I am better we should all meet where there's a whiteboard and a chest hair trimmer.

    Steve
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  3. #23
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    F1 cars and bikes have relatively big bores and tiny strokes. So that aligns with what what you said. Now don't rev a F1 or bike and it will be efficient and won't make any power. Rev it out and make power. Or, as you said, increase displacement (kind of against muly point but I'll run with it) now rev out the new larger motor and make even more power.

    The point being is to make a power dense motor, that's efficient (power per liter), you need rpm.

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    Master of Disaster SteveLevin's Avatar
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    Continuing our verge off topic (but hey, this IS trackHQ) -- I never knew companies used single cylinder prototypes to test their engines (or at Honda does).

    Supposedly that's part of how they got into trouble -- the real harmonics and vibrations of the complete engine effectively tore it apart.

    There's probably an entire Tacoma Narrows style analysis waiting to happen there

    Steve
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    Chest hair required Olitho's Avatar
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    Quote Originally Posted by SteveLevin View Post
    Continuing our verge off topic (but hey, this IS trackHQ)

    There's probably an entire Tacoma Narrows style analysis waiting to happen there

    Steve
    Honda doesn't make the Tacoma. Toyota does you silly! ;-)
    To the right of The Sheriff. Isn't everyone?

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    http://www.trackhq.com/Banners/yellowsitesponsor.gif Blackbird's Avatar
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    Quote Originally Posted by Loose Caboose View Post
    No getting around stoichiometric constraints: more fuel needs more air.
    Correct, but between the two it's the easier one to get by far - you can always inject more fuel faster.
    It's the air that you have to fight to feed.

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