[HN Gopher] Ron Patrick's Street-Legal Jet Powered Volkswagen Be...
       ___________________________________________________________________
        
       Ron Patrick's Street-Legal Jet Powered Volkswagen Beetle (2006)
        
       Author : 1317
       Score  : 240 points
       Date   : 2023-10-05 13:45 UTC (1 days ago)
        
 (HTM) web link (www.ronpatrickstuff.com)
 (TXT) w3m dump (www.ronpatrickstuff.com)
        
       | ynoxinul wrote:
       | Apparently the post is from 2006. I wonder if this contraption is
       | still street-legal.
        
         | K0balt wrote:
         | It would be legal to run it on the factory engine, at which
         | point the jet is just cargo. If you start the jet on a public
         | road, it could be considered a public nuisance, reckless
         | driving, etc.
         | 
         | If a the vehicle presents a clear and present danger of any
         | kind it is a-priory a ticketable offence at least. With the jet
         | off, it poses no such danger.
        
           | moate wrote:
           | You can own a car, you can own a flamethrower, you can't fire
           | your flamethrower out of your car while driving on public
           | roads.
        
           | psychlops wrote:
           | I'm certain an officer could find all sorts of reasons to
           | ticket that vehicle if inspired.
        
           | aidenn0 wrote:
           | And for California, don't forget "Exhibition of speed" which
           | is a rather nasty ticket to end up with.
        
         | gpderetta wrote:
         | what I really want to know if he ever finished his scooter!
        
       | zoomablemind wrote:
       | Fun read!
       | 
       | I would rather not follow a car like that on the road, hell, even
       | driving by it.
       | 
       | The looks don't signal the intent. Guess what will it do next
       | when either light starts blinking, or both? There is no known
       | signal for kicking on the jet engine! From the back it looks like
       | a gigantic cannon too, BeachBuggyRacing kind.
       | 
       | Just for kicks, I'd also put a "Student Driver" decal on the rear
       | window :).
        
       | visarga wrote:
       | [flagged]
        
       | avg_dev wrote:
       | nice... does anyone remember a K Car with a supercar engine? that
       | was not quite as crazy as this one, no jet engine, but it was
       | nice. i can't seem to find it but i remember reading about this
       | "sleeper car".
        
         | [deleted]
        
         | brucethemoose2 wrote:
         | Crazy engine swaps are not uncommon. There are some Fiat 500s
         | and such with v8 double motorcycle engines, wankels or even
         | v12s and racecar v6s:
         | 
         | https://www.youtube.com/watch?v=A52W20Z38Bw
         | 
         | https://www.youtube.com/watch?v=D6SZuionhqQ
         | 
         | A turbine _is_ relatively exotic, if only because they are even
         | more impractical.
        
           | aidenn0 wrote:
           | IIRC someone put a turbocharged 7L smallblock V8 in the back
           | of a Lotus Exige, though they had to lengthen the chassis to
           | make it fit.
        
             | brucethemoose2 wrote:
             | That is probably the Henessy Venom GT.
             | 
             | My favorite is the Ariel Atom V8, which swapped the Honda
             | Civic engine for a hilarious 483hp 3L NA V8. In a 1300lb
             | car.
        
               | aidenn0 wrote:
               | The Venom GT was indeed what I was thinking of. 1451hp in
               | a 2800lb car.
        
           | whynotmaybe wrote:
           | Even a snowblower with a HEMI...
           | 
           | https://www.ign.com/articles/2005/06/22/that-thing-got-a-
           | hem...
        
       | ed_mercer wrote:
       | > The Beetle was chosen because it looks cool with the jet and it
       | shows it off well.
       | 
       | Subjective, but I would argue that the Beetle is a terrible
       | choice and makes the jet engine look like a pole sticking out of
       | a ball. A flat sports car would probably fit the look much better
       | and mimic the aerodynamics of an aircraft.
        
       | brk wrote:
       | This is a hacker classic. Would be curious to know what
       | eventually became of it.
        
       | JoblessWonder wrote:
       | Can someone ELI20 how one would convert a turboshaft engine to a
       | turbojet engine?
        
         | mr_toad wrote:
         | Basically you just remove the shaft.
        
           | aidenn0 wrote:
           | And put a nozzle on the exhaust.
        
           | JoblessWonder wrote:
           | Ah, that makes sense. Thank you!
        
       | rmason wrote:
       | How did Jay Leno not get this car on his TV show when he had it?
       | He still is posting episodes to YouTube so it is still possible.
        
         | mywacaday wrote:
         | Jay has his own jet bike,
         | https://www.youtube.com/watch?v=WDhoYXw2IPc
        
       | latchkey wrote:
       | _Discussions on similar submissions:_
       | 
       |  _Jet Powered Volkswagen Beetle_
       | https://news.ycombinator.com/item?id=28349589 (August 29, 2021 --
       | 2 points, 1 comments)
       | 
       |  _Ron Patrick 's Street-Legal Jet Powered Volkswagen Beetle
       | (2006)_ https://news.ycombinator.com/item?id=16513835 (March 4,
       | 2018 -- 156 points, 60 comments)
       | 
       |  _Street-Legal Jet Powered Volkswagen Beetle_
       | https://news.ycombinator.com/item?id=5384390 (March 15, 2013 -- 6
       | points, 2 comments)
       | 
       |  _Street Legal Jet Powered Beetle (2006)_
       | https://news.ycombinator.com/item?id=831185 (September 18, 2009
       | -- 76 points, 23 comments)
        
         | overlyambitious wrote:
         | and still no videos online.... fishy
        
         | dang wrote:
         | Thanks! Here's a great subthread from one of those:
         | https://news.ycombinator.com/item?id=16524533
         | 
         | (I just added it to https://news.ycombinator.com/highlights)
        
           | latchkey wrote:
           | @dang I wonder why we don't just generate these things at the
           | bottom of every article? My extension does it already, but I
           | feel like it would help a lot as a core feature.
        
             | hansoolo wrote:
             | Wouldn't help me unfortunately, as I am reading HN on an
             | android app. But good idea.
        
             | dang wrote:
             | The lists that I post, and that most users post, are
             | reviewed to include only the interesting threads. This
             | makes them more valuable to readers, since the odds of
             | going on a click trip to something boring are much lower.
             | 
             | Rather than autogenerating them, I think what we'll do is
             | add software support for the community to collaborate on
             | the 'related 'list for a post. And it needn't just link to
             | related HN threads - it can be related URLs on the same
             | story, for example.
             | 
             | When we'll actually get to this is another question of
             | course...
        
               | latchkey wrote:
               | Good points. Previously [0], in your list, it doesn't
               | include the number of points, as well as the calendar
               | day, which is something that my generator includes and
               | helps prevent click trips.
               | 
               | To filter further, the list could just include posts with
               | some points + comments ratio math. Also filter out
               | similar posts within a short timeframe, if two posts
               | happen within a week of each other, pick the one with the
               | better ratio math.
               | 
               | No need to involve the community in moderation a second
               | time, since they've already involved themselves with
               | points/comments to begin with.
               | 
               | [0] https://news.ycombinator.com/item?id=37768936
        
       | xrd wrote:
       | This should be retitled "Now I'm going to finish adding jet
       | engines to my wife's scooter."
        
         | mindslight wrote:
         | The scooter seems like it could be a poor idea due to
         | asymmetric thrust, and I have to wonder if he just mocked it up
         | in jest. It does look pretty awesome though.
        
           | whatshisface wrote:
           | You could adjust the two throttles to trim it, preferably not
           | while in motion.
        
           | [deleted]
        
       | joshu wrote:
       | i know ron!
        
         | dazhbog wrote:
         | Tell him to make a YouTube channel or update us on that scooter
         | ;)
        
       | grecy wrote:
       | I'm a little shocked there's no 1/4 mile time.
       | 
       | Surely when you strap a jet engine to a Beetle you need to find
       | out how fast it goes!
        
         | dotancohen wrote:
         | Quick, not fast. Low 1/4 times are mostly associated with
         | acceleration, not speed.
        
       | omginternets wrote:
       | How on earth is it street legal to emit a high-pressure plume of
       | jet exhaust behind you?
        
         | nikanj wrote:
         | 'Murica
        
         | dzdt wrote:
         | Its street legal to drive using the standard motor with the jet
         | engine OFF.
        
           | aidos wrote:
           | > That doesn't stop me from the occasional blast on the
           | highway though.
        
             | skeaker wrote:
             | Something being road-illegal doesn't stop you from doing it
             | anyways...
        
           | omginternets wrote:
           | Oooh, it's a hybrid!
        
             | dylan604 wrote:
             | "Hmmm, the car has two engines making the car a hybrid so
             | maybe we can drive in the commuter lanes along with the
             | Toyota Priuses. "
        
               | omginternets wrote:
               | Imagine being the cop who has to argue over the ticket
               | with that guy ^^
        
               | [deleted]
        
               | ceejayoz wrote:
               | "I'm... gonna park a little further back."
        
               | [deleted]
        
               | dylan604 wrote:
               | There's a paragraph and photo of this very thing in the
               | TFA
        
         | mindslight wrote:
         | We live in a society where things are legal by default. Why
         | would adding a jet engine to a car be a priori illegal? If he
         | harms somebody or otherwise causes damage, that itself is
         | what's illegal and he'd be liable regardless of motor vehicle
         | regulations. If this mod became a larger trend, especially
         | consumer-available, then regulations would be implemented to
         | head it off. But for a few lone instances it's not particularly
         | necessary.
        
           | shortcake27 wrote:
           | 20 years ago in Australia my car got canaried because I had
           | LPG and a pod filter, which was illegal because you were only
           | allowed 1 modification to the intake system. I am 100%
           | confident that if I strapped a jet to the car, it would be
           | illegal. As it should be. If you want to do extremely
           | dangerous modifications, do it on your own property. Not a
           | public road where you risk killing a family of 5.
        
             | mindslight wrote:
             | You're speaking from an Australian perspective about _what
             | is_ , to make an otherwise unsupported argument about what
             | _should be_ in the US. I 'll be one of the first to point
             | out problems and blindspots from the American conception of
             | "freedom", but in this case it seems highly appropriate.
             | You yourself even got bit by overregulation for something
             | seemingly reasonable and forward-looking, and yet you're
             | still reflexively defending it!
             | 
             | In my estimation your example "family of 5" is at much more
             | risk from widespread unnecessarily-high bro-dozer trucks
             | than a single engineer personally adding a jet engine to
             | his car while seemingly being very in touch with the
             | dangers of operating it. In fact given the severe disparity
             | in other vehicle crash survivability statistics between
             | coupes and trucks, I've got to wonder if this car isn't
             | still _individually safer_ than a casually-driven pickup
             | truck.
        
               | gafferongames wrote:
               | As an Australian-American living in the US I can confirm
               | that the Australian concept of law (aka Nanny State)
               | would ensure that this modification is illegal by
               | default. Think of the children.
        
               | civilitty wrote:
               | Children don't really fit in the intake so it shouldn't
               | be a problem
        
               | jamiek88 wrote:
               | I was shocked as a Brit American living in the US how
               | nanny state Aust is. Even more than Britain. Certainly
               | when it comes to cars and driving. The whole 'anti hoon'
               | thing seems shocking to me with my now mostly American
               | sensibilities.
               | 
               | But I guess that's why we both live here rather than
               | blighty or down under.
        
               | defrost wrote:
               | Australia's just fine with adding jet engines to cars and
               | designing|building one million round per minute guns.
               | 
               | It's the mixing up of such things with the general
               | unconsenting public that raises an eyebrow.
               | 
               | Hoon's can hoon - just out of earshot of people that want
               | a quiet life and off the community car parks and roadways
               | - there's no shortage of private land and designated drag
               | strips | raceways.
               | 
               | https://aussieinvader.com/the-people/rosco-mcglashan-oam/
               | 
               | https://thewest.com.au/lifestyle/motoring/wa-
               | built-1600kmh-j...
               | 
               | https://en.wikipedia.org/wiki/Metal_Storm
        
               | shortcake27 wrote:
               | It's important to understand most things happen for a
               | reason, and as a Brit American living in the US you might
               | be missing some context.
               | 
               | In the area I grew up, it was expected that your first
               | car would be a V8. Hooning was ingrained into the
               | culture. Back then it was a single spinner, no ABS, no
               | airbags, basically no safety features at all. So what
               | would happen is someone would get their licence, grab as
               | many mates as they could, drive as fast as they could,
               | and wrap their car around a tree killing everyone. Every
               | week there was a news story about a multiple fatality P
               | plate accident caused by hooning.
               | 
               | A culture of dangerous driving and dangerous vehicles led
               | to Australia's anti-hoon laws. It's not just "ooh silly
               | nanny state laws for no reason".
        
               | shortcake27 wrote:
               | > a single engineer personally adding a jet engine to his
               | car while seemingly being very in touch with the dangers
               | of operating it
               | 
               | What if a non-engineer who doesn't understand the dangers
               | makes this type of modification? This is is why it needs
               | to be illegal. Just because someone straps a jet engine
               | to their car it doesn't mean they know what they're
               | doing, and _that_ is the risk, and why pretty much all
               | laws exist in the first place. Many people could drive
               | safely without speed limits, but we have speed limits to
               | cater for people who can't. My point is that if this type
               | of modification truly is legal in America, that's scary,
               | and Australia got the laws right. A jet-powered car is
               | not inherently safer in the US than Australia.
        
               | gehwartzen wrote:
               | > What if a non-engineer who doesn't understand the
               | dangers makes this type of modification?
               | 
               | This hasn't happened afaik in the last 15 years. I assume
               | any non-engineer who doesn't know the dangers also
               | doesn't have the technical know how to build this. Also
               | the cost is several hundred thousand $.
               | 
               | History seems to indicate it's a non-issue.
        
               | userbinator wrote:
               | It is likely to be safer simply because the one driving
               | it is going to be a lot more careful than the average
               | driver.
               | 
               | I recall seeing a study a while ago that showed how those
               | who work on their own cars, especially for those who do
               | major jobs like engine rebuilds, are statistically far
               | less likely to get into an accident. Unfortunately I
               | can't find it now.
        
             | historyTeach123 wrote:
             | He didn't modify the car's original factory system. He
             | simply added onto it, he added a second independent system.
             | 
             | Tbh I kinda agree this is a bit ridiculous to assume it's
             | safe to drive on the road though.
        
           | cortesoft wrote:
           | In California, you have to register your car and have it pass
           | a smog test. How would this pass that?
        
             | mhb wrote:
             | Aren't "inspections" nowadays done only by plugging into
             | the OBD port? So, no problem?
        
             | btilly wrote:
             | Just drive on the gasoline engine.
        
               | lmm wrote:
               | Doesn't the smog test require you to run your car at the
               | peak power it can do, or something like that?
        
               | btilly wrote:
               | Floor the accelerator, yes.
               | 
               | Find a toggle for an unrelated afterburner? Not so much.
        
             | jamiek88 wrote:
             | I'd hate to be the minimum wage tech tying to figure that
             | out!
        
           | lawlessone wrote:
           | I am not in the US, but where i am afaik anything that
           | modifies the car like this would have to go through some sort
           | of recertification process.
           | 
           | It would be perfectly legal on private property but not
           | public roads
        
             | dahart wrote:
             | I'd guess that's true in the US too, _if_ you modify the
             | engine or transmission or exhaust system, etc. But adding
             | something to your car without modifying the existing
             | systems has no regulation and no certification process,
             | which he sorta talks about in the article re: police
             | inability to enforce. As long as there aren't other laws
             | you violate, hanging a big fan out the window might not
             | count as modifying the car.
        
             | throwaway20304 wrote:
             | Well not sure where you are, but where in EU I am, you can
             | modify the insides of your car (people attach entire
             | apartments to the insides of their cars...), and there's
             | nothing wrong about stuff sticking outside - you just need
             | to attach a red flag if it's over 1.5m out of the car
             | (maybe red flame would be enough?).
             | 
             | The modified rear door might be a problem, but where I am
             | you could simply keep the original open, or detach it.
        
               | jamiek88 wrote:
               | Road traffic laws are absolutely not harmonized across
               | the EU.
               | 
               | French, Portuguese and German rules of the road for
               | example are all different in statutory strictness and
               | enforcement strictness.
        
           | olyjohn wrote:
           | In this case the law has already been written. It's not a
           | CARB-approved, nor EPA compliant engine. You're not allowed
           | to run it on the street. The law is written so that
           | everything you do to a car's emission system is illegal by
           | default. To make any engine modifications in California, the
           | part must be CARB approved and have a compliance sticker on
           | it. Engine swaps in California are legal, as long as the
           | engine being swapped is at least as new as the engine in the
           | vehicle and meets the same regulatory requirements. Which
           | means you swap in another EPA/CARB approved engine, but not a
           | jet engine.
        
         | wkat4242 wrote:
         | Jet exhaust doesn't need to be high pressure. It depends. For
         | example a turboprop engine doesn't provide any jet thrust and
         | usually the exhaust is even pointed away from the direction of
         | flight.
         | 
         | But it is very hot so exhausting it close to the ground or
         | people is a serious problem.
        
       | Miserlou57 wrote:
       | My buddy (a car guy) from Mountain View told me he could hear
       | this thing on 280 late at night every now and then. Anyone else?
        
       | Aurornis wrote:
       | Awesome project, but are there any actual videos of it running
       | the jet engine?
       | 
       | He says the jet engine moves 11,000 CFM of air, but that air can
       | only come through the windows and the sunroof. Pulling 183 cubic
       | feet of air per second through those little openings while
       | sitting in the drivers seat isn't going to work. Just try to do
       | the math on how fast that air would have to be moving through
       | those windows.
       | 
       | Cool show piece though.
        
         | samtho wrote:
         | This not a typical low-bypass, cigar-type turbofan jet engine
         | you see on airplanes, rather, it's a modified turboshaft jet
         | engine used for helicopters, intended to provide longitudinal
         | rotational energy. The air it moves from the intake is a
         | fraction of what it produces as the combustion process itself
         | results in gasses being chemically formed. There is no
         | propeller or fan on this engine - it's closer to a rocket than
         | what we think of as a jet.
        
           | lmm wrote:
           | > it's a modified turboshaft jet engine used for helicopters,
           | intended to provide longitudinal rotational energy. The air
           | it moves from the intake is a fraction of what it produces as
           | the combustion process itself results in gasses being
           | chemically formed.
           | 
           | It's not a turbofan no but it's a jet engine burning fuel the
           | regular way (using air), like the ones on a B-52 or Concorde.
           | Very different from a rocket engine that carries its own
           | oxidiser.
        
             | samtho wrote:
             | I'm fully aware of the difference. The only parallel I've
             | drawn is the fact that it uses gases as a result of the
             | combustion as propulsion rather than spinning a fan.
             | Whether it has its own oxidizer is irrelevant for the
             | purposes of this analogy as I don't see this vehicle
             | achieving any sort of space flight.
        
         | ceejayoz wrote:
         | Yes, there's video online.
         | 
         | https://www.youtube.com/watch?v=TCqxWhKe_tA
         | 
         | https://www.youtube.com/watch?v=5zNdkXwFQ3c
         | 
         | (Noise warning, for obvious reasons.)
        
           | avg_dev wrote:
           | I see
           | 
           | > I don't know how fast the car will go and probably never
           | will. The car was built to thrill me, not kill me. That
           | doesn't stop me from the occasional blast on the highway
           | though.
           | 
           | but I am unsure if that means he has never driven it using
           | the jet engine, or whether the engine even will power the car
           | or just kinda runs on its own. I'm curious to see it go at
           | all under jet engine power.
           | 
           | Edit: maybe this is it
           | https://www.youtube.com/watch?v=R-ipYAl3o40
        
             | jefftk wrote:
             | That videos's an original Beetle, not a New Beetle.
        
             | dmurray wrote:
             | I think he means he's used it plenty, but hasn't tried to
             | max out the speed.
        
               | ceejayoz wrote:
               | That's my reading as well.
               | 
               | I have a vague memory of this site or an interview
               | previously saying he got up to 130 mph once, before
               | deciding he'd rather not find out what speed a VW Beetle
               | lifts off the pavement.
        
         | sokoloff wrote:
         | Give 6 sq ft for openings, that's around 30 linear feet per
         | second. ~30 feet per second is ~20 miles per hour. That's a
         | stiff breeze, but it doesn't seem outrageous.
        
       | [deleted]
        
       | ralfd wrote:
       | Comments from 2018:
       | 
       | https://news.ycombinator.com/item?id=16513835
        
       | [deleted]
        
       | smohnot wrote:
       | He had it listed on Craigslist a few years ago... for $550k.
       | Anyone know the current status of it?
       | 
       | https://www.autoevolution.com/news/get-yourself-the-iconic-j...
        
         | stergios wrote:
         | It's still sitting in his shop. RP is not going to sell it.
        
           | KennyBlanken wrote:
           | I think it's more that like most modded / custom car owners,
           | he thinks that it's reasonable to set an asking price
           | according to the following formula:
           | 
           | (Cost of car) + (Cost of Mods) + (My time x some magical
           | hourly rate) = reasonable asking price
           | 
           | The more sane of them add in a multiplier, like say .5 to .8.
           | Or leave out their time.
           | 
           | Reality is:
           | 
           | What 1 person among the people who hear about the sale will
           | pay = reasonable asking price
        
             | jamiek88 wrote:
             | Yeah things like that are always the same.
             | 
             | It's the sellers dream, rarely anyone else has the exact
             | same dream.
             | 
             | If they have a similar dream all they see is the
             | differences and what they'd do differently.
        
       | historyTeach123 wrote:
       | [flagged]
        
       | hrichards wrote:
       | Seems like a good time to ask this question that has been bugging
       | me forever, since all the HN jet nerds will be drawn to this
       | thread:
       | 
       | Why hasn't anyone made a hybrid car that uses a gasoline-powered
       | turbine generator to charge its batteries instead of a piston
       | engine?
       | 
       | I'd imagine that hooking up such an engine directly to the
       | drivetrain like in a Prius would be difficult, but surely a small
       | turbine with one hell of a muffler running a generator (similar
       | to a natural gas power plant), both running only at their peak
       | efficiency RPMs, would yield a very efficient car that could
       | still use the extant gasoline infrastructure.
       | 
       | I'm sure there are very interesting reasons, either due cost,
       | noise, reliability, or durability, that this idea hasn't taken
       | off, and I'm very interested to hear y'all's thoughts on the
       | subject. Or maybe there has been progress in this area, and I'd
       | love to see some links!
        
         | mixmastamyk wrote:
         | Sounds like you just described a hybrid, only needs a larger
         | tank.
        
         | usrusr wrote:
         | I've been wondering about this very same question a lot myself
         | and accidentally stumbled across the answer just a few days
         | ago: Efficiency of turbines smaller than grid scale is simply
         | not anywhere close to what piston engines can do at e.g. car
         | size. Even at naval scale, turbines only win in use cases where
         | power density is more important than fuel efficiency.
         | Helicopters are deep in the (specific) camp of power density
         | beats efficiency because carrying a heavier but more efficient
         | engine would easily eat the fuel savings. Fixed wing aircraft
         | gain range by climbing high, but up there both efficiency and
         | power density of piston engines decreases dramatically with
         | decreasing air density, so they are also in the camp of power
         | density over efficiency (turbines are also affected, but not
         | quite as much).
         | 
         | Note that despite all this, the Otto Aviation 500L that is all
         | about fuel efficiency at high altitudes uses a piston engine
         | (they probably put a lot of effort into their turbocharger,
         | those can lessen the impact of thin air)
        
           | KennyBlanken wrote:
           | The bit about the naval use and efficiency isn't quite
           | accurate.
           | 
           | The issue isn't that they're not efficient. It's that they
           | are only efficient at high power level, and the minimum power
           | level they're efficient at (and even their minimum power
           | level, period) - is quite high. To compare: Britain's current
           | aircraft carrier has four diesels that total 40MW...combined
           | those diesels equal one of its two 40MW turbines.
           | 
           | This minimum power level is why jet airplanes have an APU,
           | and often taxi with just one engine running, with the second
           | started up with enough time to get up to operating
           | temperature for takeoff.
           | 
           | Example: https://en.wikipedia.org/wiki/Rolls-Royce_MT30
           | 
           | ~40MW, minimum efficient power level 25MW.
           | 
           | 25MW, even if it's very efficient in terms of turning
           | kerosene into shaft power, means the ship is moving really
           | fast, and thus there's enormous fuel consumption and drag.
        
             | taneq wrote:
             | Then wouldn't they just have a 5MW turbine and run it at
             | its peak efficiency?
        
             | usrusr wrote:
             | I don't think that it's just inefficiency at certain power
             | levels:
             | 
             | The big table on https://en.wikipedia.org/wiki/Brake-
             | specific_fuel_consumptio... has the Marine Trent rated less
             | efficient than some car engines. And that table is peak
             | efficiency, not efficiency at some arbitrary inconvenient
             | power level.
             | 
             | But you are right in so far as efficiency at the low end of
             | the power range is very important in commercial shipping.
             | Because the energy demand (at the drive shaft) of a given
             | trip is highly dependent on the desired speed and if going
             | show ruins your engine's efficiency any dip in demand will
             | ruin you economically (because others on the market are
             | much better at compensating the dip by "slow steaming")
        
           | jabl wrote:
           | Another reason many navies like turbines is that big diesels
           | produce a lot of low frequency noise which travels very far
           | underwater, so submarines can hear you coming from a very
           | long distance.
           | 
           | Although many navies do operate combinations of diesels and
           | gas turbines (CODAG etc.), in such cases the diesels need to
           | be installed on special shock absorbing mountings, in some
           | cases even with a diesel-electric drive to avoid coupling the
           | vibrations of the engine to the hull via the propeller shaft.
        
           | anjel wrote:
           | Celebrity and Cunard built a few Cruise ships that use
           | turbines to generate power to its electric motor
           | propulsion.[1] They regret the endeavor owing to cost of
           | operation.[2]
           | 
           | [1]https://www.ge.com/gas-power/industries/cruise-lines
           | 
           | [2]https://www.airliners.net/forum/viewtopic.php?t=1202425
        
         | Lanrei wrote:
         | You'd be better off with an engine specifically designed to be
         | efficient. Turbines are great at many things, but they are
         | complex and don't scale down very well. They were primarily
         | used where high torque and power is required, and they just
         | aren't practical outside of that.
         | 
         | A better option would be a constant speed ICE engine running at
         | it's peak efficiency (like a diesel-electric train).
        
         | xattt wrote:
         | I don't have the source at hand, but a gas turbine is
         | ridiculously inefficient for variable loads. At idle, fuel
         | consumption can be ~35% of what it is at full power.
         | 
         | It would only need to charge for short time, and subsequently
         | shut off. When a charge top-up is required, startup would be
         | another rigamarole.
         | 
         | Now, rotary engines, that's a different story...
        
           | playworker wrote:
           | https://www.mazda.co.uk/cars/mazda-mx-30-r-ev/
        
         | symmetricsaurus wrote:
         | Volvo did this back in 1992 but only as a concept vehicle
         | https://en.m.wikipedia.org/wiki/Volvo_ECC
        
         | mschuster91 wrote:
         | > Why hasn't anyone made a hybrid car that uses a gasoline-
         | powered turbine generator to charge its batteries instead of a
         | piston engine?
         | 
         | Because turbine engines have some pretty serious downsides.
         | Compared to a piston engine, they guzzle fuel [1], they're
         | pretty complex to repair (which is one of the problems Ukraine
         | is facing), they spin at absurd RPMs which means that they need
         | some serious housing to not turn into a shrapnel dispenser in
         | case of an engine failure or accident, and they produce an
         | awful lot of hot exhaust gas at high velocity that needs to be
         | dissipated somewhere - down isn't OK because it will melt the
         | asphalt, sideways is not OK because it will melt or injure
         | anyone and anything next to the car, and upwards carries
         | serious risks as well (e.g. if you're in a tunnel).
         | 
         | [1] https://www.augsburger-allgemeine.de/politik/panzer-
         | vergleic...
        
         | salty_biscuits wrote:
         | But they have
         | 
         | https://en.m.wikipedia.org/wiki/Jaguar_C-X75
         | 
         | Turbines get more efficient as they get bigger.
        
         | Animats wrote:
         | It's been done a few times, as listed here.
         | 
         | One not mentioned was someone in Southern California who got an
         | old aircraft APU (probably a Solar T-62[1] or similar) and made
         | an electric hybrid back in the 1980s. The APU charged the
         | battery, and shut down when the battery was full. Worked OK,
         | apparently.
         | 
         | The trouble with turbine engines is that, below bizjet size,
         | they don't seem to get any cheaper. Not for lack of trying in
         | the 1990s. NASA, Williams International, and Eclipse tried
         | hard. There were a few prototype planes, but no commercial
         | success. There are today what are called "very light jets", but
         | this means 4-6 people and and a price around $2 million.
         | 
         | General aviation is still mostly piston-powered. There are tiny
         | jet engines for R/C planes, but they have very short operating
         | lives.
         | 
         | [1] https://en.wikipedia.org/wiki/Solar_T62
        
           | mschuster91 wrote:
           | > The trouble with turbine engines is that, below bizjet
           | size, they don't seem to get any cheaper.
           | 
           | That's because of the lack of demand. GA is _extremely_
           | conservative, most designs date back to the 50s-70s and the
           | more modifications you make to a design the more extensive
           | and expensive certification becomes. They 're still flying
           | with leaded fuel, many decades past the removal of lead in
           | car fuel, because up until last year there hadn't been a
           | certified alternative (and the one that is is not suspected
           | to be readily available until 2027+).
           | 
           | For a jet engine powertrain on a plane the size of a Cessna,
           | you'd need to redesign the whole frame, you'd need to design
           | appropriately sized engines and maintenance procedures, and
           | you'd need to re-train all the pilots. Before that happens,
           | GA will go electric.
        
         | historyTeach123 wrote:
         | [flagged]
        
         | jabl wrote:
         | As mentioned in a sibling comment, turbines don't scale down
         | very well. Boundary layer friction gets relatively worse for
         | smaller turbines, and AFAIU small turbines have relatively
         | larger inefficiency due to air leaking past between the blades
         | and the casing, etc.
         | 
         | There's a couple of companies working on recuperated turbine
         | engines for small aircraft in the few hundred kW range, remains
         | to be seen whether any of these will succeed.
        
         | iancmceachern wrote:
         | The military has made several "micro turbine generators" Here
         | is a report on one:
         | 
         | https://apps.dtic.mil/sti/citations/ADA515623
         | 
         | My guess the answer to your question would be cost.
        
         | h2odragon wrote:
         | i think even the tiny, model jet engines used in radio control
         | planes are both very hot, and move lots of air. both of which
         | are hard to tame to the point of making them comfortable to
         | coexist with on a city street in large herds.
         | 
         | I still want one. direct the exhaust forward, dump in a little
         | extra fuel, and instant snowblower / flamethrower. Makes that
         | pesky crosswalk crowd just melt away.
        
           | jacquesm wrote:
           | And turns it into a skating rink five minutes later. You want
           | the snow to go away, not to change into liquid water on a
           | sub-zero stone substrate.
        
             | h2odragon wrote:
             | Excellent point, but i must rebut: (a) i'm already on my
             | way by then, and (b) FIRE! </beavis>
        
           | rainbowzootsuit wrote:
           | It's a(t least one) thing. Test run before the snow gets too
           | deep:
           | 
           | Jet Powered Blower
           | https://www.youtube.com/watch?v=BcEkt5vQTVQ
        
         | clucas wrote:
         | Having an ICE that drives a generator (alternator?) to power a
         | traction motor(s), without being mechanically linked to the
         | drivetrain, is how diesel locomotives operate. I believe the
         | concept also has been (is being?) explored for linehaul trucks.
         | But I'm not sure what constraints there are on passenger
         | vehicles though... I'm also curious.
         | 
         | If I had to guess, I would bet that the constraints are more
         | commercial than physical... hybrids are already very efficient,
         | so the market for such a vehicle would probably not justify the
         | engineering costs. But that's just a guess!
        
           | linkjuice4all wrote:
           | Union Pacific tried using turbines in the 50s[0] but fuel
           | consumption was an issue (I think they had to keep the
           | turbine idling and maybe throttling wasn't as easy?). Also
           | mentioned in the wiki article was the low-grade fuel they
           | were used was able to be used for plastic manufacturing
           | instead of just burning it.
           | 
           | The bigger difference between locomotive applications and GPs
           | question is around charging batteries as opposed to running
           | motors or directly turning the wheels. Efficiency of the
           | smaller turbine is mentioned in another comment - but I have
           | to imagine you'd also see some loses going from turbine to
           | generator to battery and then to electric motor.
           | 
           | [0] https://en.wikipedia.org/wiki/Union_Pacific_GTELs
        
             | KennyBlanken wrote:
             | Diesels idle pretty efficiently whereas jet turbines have
             | very high minimum amounts of power.
             | 
             | In terms of efficiency losses between the turbine,
             | generator, battery, and motor - no, not really; look at
             | most modern hybrid cars.
             | 
             | Lithium ion battery coulombic efficiency is in the high
             | 90's percentage-wise, by the way.
             | 
             | I would imagine that we might see hybrid turbine
             | locomotives as battery power density and cost continue to
             | improve.
        
           | teeray wrote:
           | The MBTA uses jet engines as giant hairdryers to melt snow
           | off the Mattapan High Speed Line [0]. I'm not sure if it's
           | also serving as the prime mover, but even if not it's still
           | an interesting and unusual application.
           | 
           | [0] https://youtu.be/DL6jKOCeVec
        
         | jgable wrote:
         | Wrightspeed did this a while (10 years?) ago. It looks like
         | they have since pivoted to fully electric powertrains for
         | buses, but when they first started they were doing range-
         | extending hybrid powertrains for heavy trucks. I found an
         | article the describes the system at the time:
         | https://www.e-hike.net/tr/content/wrightspeed-unveils-new-
         | turbine-range-extender-medium-and-heavy-duty-electric-
         | powertrains-30
         | 
         | With a range-extender hybrid system, you can keep the turbine
         | closer to its peak-efficiency operating point, since it only
         | has to handle steady-state load while the battery takes up the
         | spikes. Not sure how it would do up a long grade, but I imagine
         | they designed for that.
        
           | p1mrx wrote:
           | Video of a Wrightspeed truck:
           | https://www.youtube.com/watch?v=sIAosHyqARA
        
         | thebutcher wrote:
         | I think someone is making this, or maybe I misunderstood your
         | question. The Ariel Hipercar uses a jet engine to power it's 4
         | electric engines. I think it's just used as a range extender,
         | and last I saw they didn't have it working yet. It's been a
         | while since I checked up on the car.
         | 
         | EDIT: I just read this article from 2023 that says the turbine
         | engine still isn't working:
         | https://www.evo.co.uk/ariel/206120/ariel-hipercar-prototype-...
        
         | TuesdayNights wrote:
         | Arnold Schwarzenegger's Hummer from the early 2000's is setup
         | like this -- 100mpg with bio-diesel. I think this is the
         | original article I read about his car's creator, Johnathan
         | Goodwin, from years ago.
         | 
         | https://www.autoblog.com/amp/2007/10/20/biodiesel-turbine-su...
        
           | zdragnar wrote:
           | Per the article, he claimed the Hummer would get 60, the 100
           | number was aspirational based on ideas he had for future
           | designs.
           | 
           | (Still pretty awesome. If it didn't likely cost more than
           | what truck is worth I'd want it too)
        
         | RachelF wrote:
         | I worked for a company that did this in the 1990's. Small gas
         | turbine, the size of two show boxes (200hp) powering a
         | generator, which charged the batteries and/or electric motors.
         | 
         | The advantages are efficiency, low weight and no gearbox is
         | needed, as the turbine spun at over 100,000 rpm and the
         | generator was fine with that.
         | 
         | The main disadvantages were noise and turbines need more
         | maintenance than piston engines. No LiIon batteries back then
         | either.
         | 
         | The project only built 1 finished prototype.
        
         | Scene_Cast2 wrote:
         | To add to the discussion - the M1 Abrams tank uses a turbine. I
         | don't know how that's linked up to the tracks though.
        
           | ithkuil wrote:
           | Interestingly, that engine has good power to weight ratio,
           | has a better noise profile (higher pitched noise, that
           | doesn't transmit far, albeit louder locally), can operate
           | with a variety of fuels, and can handle arctic conditions.
           | 
           | The downside is that it consumes 50% more fuel than a
           | comparable diesel engine.
        
           | mr_toad wrote:
           | The turboshaft is linked to reduction gearing. I'm not sure
           | how it's linked to the sprocket that drives the tracks but
           | it's probably a chain, like on a motorcycle.
        
           | efitz wrote:
           | Former M1 Abrams crewman (19K). It has an automatic
           | transmission.
        
           | shagie wrote:
           | I recently stumbled into a couple of YouTube videos on turret
           | design for tanks.
           | 
           | * What actually IS an "Oscillating" turret?
           | https://youtu.be/46k7uhPHpLY
           | 
           | * What happened to Rear-Mounted Turrets?
           | https://youtu.be/g5DOf2eZW3Y
           | 
           | At 4:24 in the rear mounted turret video it touches on the
           | aspects of modern transmission.
        
       | usrusr wrote:
       | "The car has two engines: the production gasoline engine in the
       | front driving the front wheels and the jet engine in the back."
       | 
       | Careful wording to give the impression that the drive shaft of
       | the helicopter turbine would be connected to the rear wheels,
       | without actually claiming that it is. So it's a car with a large
       | flame thrower in the back, minor The Boring Company vibes.
       | 
       | Well possible that the author might have had more fun writing
       | than building/driving. (I do love the incredulous tone of "#1
       | Does this mean I'm the right hands?")
        
         | UniverseHacker wrote:
         | It produces thrust in the normal way a jet engine aircraft
         | does... with high exhaust velocity. From the videos you can see
         | shock diamonds, so it is producing supersonic exhaust.
        
         | alright2565 wrote:
         | I don't think so. In another part he mentions
         | 
         | > This is a helicopter turboshaft engine that was converted to
         | a jet engine
         | 
         | I can't see a way to get rotary power out of this engine after
         | the modifications.
        
           | usrusr wrote:
           | Any turboshaft engine is a jet engine if you don't connect
           | anything to the shaft and point the exhaust in the right
           | direction. Just not a very good one, at zero bypass.
           | 
           | If you think there is anything done in this project to
           | increase performance you are missing the point of the joke:
           | woah, jet engine! Woah, rated 1350 horse power! Heh, retro
           | novelty compact with a truly glorious amount of hot air.
           | 
           | Will the turbine exhaust noticeable push the car? Sure. Even
           | a piston engine exhaust does, e.g. some versions of the
           | Merlin engine claim extra 70 HP from exhaust thrust.
           | 
           | Is the author having great fun (and readers who get it) by
           | brandishing the rated rotary power of the turbine over and
           | over again, while carefully avoiding any mention of actual
           | performance of the car? Absolutely. But it's not mean
           | deception, it's friendly trolling. Which is basically the
           | essence of the entire hot rod idea. I dislike the waste (of a
           | good car, and the occasional kerosene burn, the turbine was
           | probably beyond airworthyness certification and thus scrap
           | anyway), but I find his "friendly trolling" charming in a
           | surprisingly deep way.
        
         | ben7799 wrote:
         | For a stunt car like this there's not a huge need or desire to
         | have it powering the wheels at all.
         | 
         | The direct air thrust will push the car just fine, doesn't need
         | a transmission, has zero issues with wheel spin or traction,
         | and so then doesn't require re-engineering the wheels/tires and
         | then the suspension and/or chassis to handle 1350hp.
        
           | jamiek88 wrote:
           | Yeah imagine the rubber! They'd need American drag racing
           | tyres!
        
       | generalizations wrote:
       | > You have to give the California Department of Motor Vehicles
       | (the DMV) credit for creativity on this one. A DMV insider has
       | disclosed to me that the DMV has made a formal request to a
       | federal agency to rule if my Beetle constitutes a threat to
       | national security based on what could happen if it got into the
       | wrong hands. This raises three questions in my mind: #1 Does this
       | mean I'm the right hands? #2 If someone with the name "b_laden13"
       | is the highest eBay bidder for my Beetle can I refuse his offer
       | even if he has the prestigious eBay Red Shooting Star feedback
       | rating (the highest)? #3 Would this affect my eBay rating?
       | 
       | Wonder if they ever found a way to give the guy a ticket.
        
       | literarylover wrote:
       | [dead]
        
       ___________________________________________________________________
       (page generated 2023-10-06 23:02 UTC)