[HN Gopher] How the McMurtry Electric Fan Car Clocked a 7.9-Seco...
___________________________________________________________________
How the McMurtry Electric Fan Car Clocked a 7.9-Second Quarter-Mile
Author : clouddrover
Score : 102 points
Date : 2022-12-17 09:36 UTC (3 days ago)
(HTM) web link (www.thedrive.com)
(TXT) w3m dump (www.thedrive.com)
| jdfellow wrote:
| The Gordon Murray T.50 hypercar also has a downforce fan.
| https://gordonmurrayautomotive.com/cars/t50s
| jackmott42 wrote:
| Kind of, it doesn't use a skirt or suck the car towards the
| ground. It uses a fan to guide the air allowing for steeper
| diffuser angles than would normally work. So you get an
| indirect downforce improvement.
|
| In the end you get an effect that is 1 or 2 orders of magnitude
| smaller than sucking the car to the ground with a skirt.
| Mesopropithecus wrote:
| Given the car is lightweight while the fan generates such strong
| downforce, would it lift off if it was to actually flip over?
| jackmott42 wrote:
| no, you can get a lot more downforce with a skirt sealed
| against the road (nearly) than you would get in open air just
| trying to thrust upward.
| rad_gruchalski wrote:
| No, it's worth watching this video:
| https://m.youtube.com/watch?v=TptzkkbC1vE.
| zinxq wrote:
| The human is starting to look like the weakest link.
|
| For such a closed track (known route to the centimeter,
| guaranteed no obstacles, etc) - a Self-Driving version of this
| could do it a good deal faster.
| killingtime74 wrote:
| There is no point without a human, what's the difference
| between that and a bullet/missile?
| tshaddox wrote:
| You could still have human operators. Competitive drone
| racing is pretty neat.
| rad_gruchalski wrote:
| Meh.
| nwienert wrote:
| AI plays better chess but no one watches them in tournaments.
| luma wrote:
| You would think that to be true, but I don't know that any
| serious attempts (of which several have been made, see RoboRace
| et al) have yet bested a human driver.
| orbital-decay wrote:
| _> The human is starting to look like the weakest link._
|
| Human is a weakest link since 80s. That's the entire reason
| Group B has been cancelled and F-1 regulated into oblivion.
| hef19898 wrote:
| It took WRC all of two years to be faster than Group B.
| Turned out focusing on suspension and handling improved
| performance more than pure performance. That being said,
| Group B was just awesome and crazy. And not just because of
| the cars or the drivers, spectators were just as crazy, as
| were officials with their utter disregard for safety.
| Rastonbury wrote:
| Yeah I'd like to see that one day on regular tracks, a true
| mechanical and AI engineering arms race. Though I think it
| would be too expensive
| rolivercoffee wrote:
| There was a driverless series in development
| https://en.wikipedia.org/wiki/Roborace
|
| Unfortunatly it looks like it might have floundered
| ambicapter wrote:
| The downforce fan technique was also done by Formula 1 in the
| late 70s before being banned the year after.
| https://en.wikipedia.org/wiki/Brabham_BT46#Brabham_BT46B_%E2...
| joncrane wrote:
| It was actually banned almost immediately after convincingly
| winning its inaugural race, at the hands of the legendary Niki
| Lauda.
| dom96 wrote:
| I wonder why it still remains banned. Surely once all cars
| can get the same fans it should be allowed?
| adrr wrote:
| They need to slow the cars down to be safe. Recently,
| there's a push to make the cars cheaper.
| m3kw9 wrote:
| Tradition vs too much complexity balance. Adding too much
| smarts will make it the driver uses less and less skill.
| Adding fans would just make the car more likely to break
| down and screw up dynamics.
| jasonwatkinspdx wrote:
| F1 stopped chasing the frontier of what's possible
| engineering wise back in the 80s. Cars were already potent
| enough then to exceed human capacity, even the very best
| drivers. F1 rule makers shifted to stuff they saw as the
| intersection of good racing and useful R&D for automakers.
|
| In fact there's almost no racing events that have a true
| open class engineering wise anymore. It's just too
| dangerous. Look up what happened during the Group B Rally
| era for examples of how it can go wrong and blow back.
| animal_spirits wrote:
| It would suck up rocks, dust, and debris from the track and
| spit it out to the driver behind. There are interviews with
| drivers complaining about it from the very start.
| Ekaros wrote:
| I think main goal is to avoid big deadly accidents. Drivers
| dying is not good out look for a sport from marketing
| standpoint. As such lot of thought is put in making the
| races slower and removing failure points that can lead
| uncontrollable 300km/h rockets. Like fan failing at end of
| straight and car becoming uncontrollable then crashing to
| concrete barrier. Very nasty for driver and possibly the
| audience and people next to track.
| lljk_kennedy wrote:
| Costs cap most likely.
| VBprogrammer wrote:
| We could build a car which no human being could survive a
| 100 mile race in today. The human is the limiting factor so
| we have to limit the technology to what humans (even elite
| sportsmen) can deal with.
|
| There are all kinds of restrictions added to race cars of
| almost any series, some for commercial reasons (promoting
| the original vehicle in rallying and touring cars for
| example), some for financial (generally to keep the price
| of entry reasonable) and sometimes for safety.
| smm11 wrote:
| Not at all related, but I watched the various motorcycle
| jumps of the Caesars Palace fountains the other day.
|
| Watching Travis Pastrana jump the fountains on a fairly
| heavy Indian flat track bike, with modern ramps designed
| with computer input, and planning rather than seat-of-
| the-pants go-for-it-ness made it okay, but hardly death-
| defying. I see guys jump motorcycles furthers on the
| dunes in Southern California. When EK did it, it was
| terrifying.
|
| Just like F1 was, once upon a time. Now F1 is scary
| because speeds are up against human reaction. It's
| inevitable the cars either have to slow down, or the
| driver needs to be on controls not in the car, making
| this ground-based drones.
| fnimick wrote:
| Relevant XKCD: https://what-if.xkcd.com/116/
| barkingcat wrote:
| F1 racing bans a lot of tech. For example, anti-lock brakes
| and AWD are banned in F1.
|
| Just because all cars can get it easily doesn't mean F1
| want it. Most often the quoted reason is to have a better
| spectator sport and to make it safer. I really doubt those
| reasons because you can still have a difficult and tight
| race while having all the modern safety features. For
| example why don't F1 cars have entire car air bags (ie air
| bags that envelop the entire car that deploy when the car
| goes airborne in a crash/rollover)? if it's too "heavy"
| just make a rule that all F1 cars need to have air bags so
| the playing field is even.
|
| F1 cars should have self driving collision avoidance that
| can activate faster than human response times as well. that
| would be way safer for everyone involved.
| JustLurking2022 wrote:
| Anthony that causes the car to behave in a way the driver
| isn't expecting (collision avoidance) would probably lead
| to less safety rather than more. Besides, even Tesla
| autopilot can be fooled and certainly isn't designed for
| cars driving inches apart.
|
| The air bags have been covered in other comments but
| similarly would probably reduce safety, not increase it.
| The cars are very much designed for safety, and to absorb
| impacts, which is why they are so much heavier than
| previous generations.
| perryizgr8 wrote:
| Why not go all the way and just have RC F1 cars that are
| remotely driven like FPV drones? Then the cars can do
| truly insane stuff without any danger to the driver. But
| I feel it wouldn't be F1 anymore if this happens.
| bitexploder wrote:
| FPV1 would be a different sport. The element of danger is
| part of why so many are drawn to it.
| SonOfKyuss wrote:
| As far as anti-lock brakes and collision avoidance goes,
| most racing leagues tend to avoid tech that automates
| driver actions. The argument is that it makes it less
| sporting if the computers are doing the driving. Of
| course, those policies can be at odds with driver safety
| at times.
| nier wrote:
| I wonder whether an airbag enveloping the whole car would
| have been advantageous in the case of Romain Grosjean's
| crash in Bahrain in 2020.
|
| He might have bounced off the guard rail or be stuck in
| it just the same with extra material surrounding him and
| catching fire.
|
| There have been also at least two cases I remember of
| race cars becoming airborne after touching wheels and
| being able to continue the race. This usually happens
| when the field is packed after (re)starts. Deploying
| airbags in such cases would probably entail a chain
| reaction that might resemble corn being popped.
| micheljansen wrote:
| I would watch F1 popcorn edition!
| gigatexal wrote:
| I thought F1 was used by manufacturers as a way to
| justify tremendous R&D, is that the case still? was it
| ever?
| bitexploder wrote:
| The problem is a lot of the R&D is focused on a very
| esoteric end itself. Sure, some of that technology ends
| up back at the parent companies and makes its way to
| consumer tech, but most of it just solves the problems of
| the moment to win races. They do push the envelope for
| material sciences more than anything else, but a lot of
| the engine design and other such things are wildly
| inapplicable to consumer tech and never will be. They can
| build million dollar engines out of rare and exotic
| materials that will never be consumer facing because they
| need 12 of them or whatever.
| fnimick wrote:
| So, fun racing/physics lessons learned here: the reason
| fan cars and (in general) primarily ground effect cars
| are banned are because of unpredictability leading to
| unsafe situations. In a car that uses underbody suction
| to create downforce, any loss of a seal suddenly reduces
| grip that could leave cars unable to steer, brake, etc
| and cause much more severe accidents than a car with
| over-body downforce that still has that benefit of
| downforce even in an accident to slow down as much as
| possible before impact.
| ben7799 wrote:
| This is mostly a bad argument. F1 rules cause all kinds
| of similar problems due to their arbitrary rules. It's
| very easy for the aerodynamic rules to result in
| unpredictability.
|
| The last 10 years many of the F1 cars due to the rules
| had catastrophic loss of downforce if they got too near
| other cars. The drivers had to work around this by not
| following too closely. F1 rules changes recently have
| tried to reduce these kinds of issues.
|
| But even this last season was somewhat ruined by one team
| figuring out to work within the current rules and not
| have the porpoising problems that wrecked the other teams
| cars because they'd lose their downforce. That made the
| racing less exciting. And the whole problem never had to
| exist if it wasn't for the rules.
| fnimick wrote:
| > catastrophic loss of downforce if they got too near
| other cars. The drivers had to work around this by not
| following too closely
|
| While the downforce loss was significant, it was
| predictable and could be easily avoided. The equivalent
| for ground effect, e.g. hitting a bump or curb mid-corner
| and lifting the skirt just far enough for the pressure
| seal to fail and your downforce to go from 100% to near
| 0% in an instant, is far more likely to lead to a
| catastrophic accident.
| Someone wrote:
| > The last 10 years many of the F1 cars due to the rules
| had catastrophic loss of downforce if they got too near
| other cars.
|
| But I don't remember catastrophic loss of downforce as
| bad as this: https://youtu.be/e21ZjwZGjiQ
| ryndbfsrw wrote:
| The BT46B being banned after a single race is a bit of an
| urban legend. It was not banned and was perfectly legal to
| run for the remainder of the year.
|
| The background to why Gordon Murray (designer) decided to go
| with the fan design was the flat-12 engine used by Brabham
| didn't allow venturi tunnels along the side of the car
| (flat-12s being too wide) so he had to find another way to
| respond to the then-new ground-effect others were exploiting.
|
| A neat legal trick was discovered: a fan could be installed
| on the car as long as its primary purpose was to cool the
| motor. Primary purpose in this case meant, and GM got a
| lawyer's opinion on this, at least 51% of the volume of air
| went to cool the engine. Brabham was very clear this fan
| sucked the car to the ground but also proved to the governing
| body that most of the air went to cooling, so it was deemed
| legal for the rest of the year but the loophole was to be
| closed for the following year. Stories by Andretti about the
| BT46 throwing stones and being dangerous to other drivers was
| complete rubbish made up by Colin Chapman to get the car
| banned as he saw Brabham would walk away with the
| championship. In effect the tips of the fans never moved
| particularly fast (ballpark 50mph along the edges) so it was
| never dangerous to other drivers.
|
| The actual story as to why it was withdrawn is Bernie
| Ecclestone, then owner of the Brabham team was also the head
| of the Formula One Constructors Association and the other
| manufacturers threatened to leave the association if he
| didn't withdraw the car. Seeing the bigger picture of
| securing TV and advertising rights to F1, Bernie withdrew the
| car after a single race.
| LBJsPNS wrote:
| It was done earlier by Jim Hall with the Chaparrals.
|
| "Although it was quickly banned, the 2J "vacuum cleaner"
| concept was copied eight years later by Brabham Formula 1
| designer Gordon Murray who figured out a way to circumvent the
| rules." - Wikipedia
|
| https://en.wikipedia.org/wiki/Jim_Hall_(racing_driver)
| eager_noob wrote:
| Figuring out a way to circumvent the rules was the reason for
| the F1 car being fascinating, and successful. It being a
| competition involving building the fastest car confirming to
| the prescribed Formula.
| joshu wrote:
| OG Can-Am was different - there were fewer rules, so things
| were limited by drivability. (Someday I hope to add a Can-
| Am car to my collection but I am also limited by
| driveability)
| lelag wrote:
| > It weighs less than one ton and boasts two electric motors that
| produce up to 1,000 hp. According to Chief Engineer Kevin Ukoko-
| Rongione, that's more than one horsepower per kilo
|
| Good thing it was pointed out by the Chief Engineer. I wonder how
| he worked it out but I guess we can trust him... /s
| jgalt212 wrote:
| What's the record for the quarter-mile using a high school track?
| That I would pay to see.
| westmeal wrote:
| Here's a honda civic hatch doing a 6.9 second 1/4 mile.
|
| https://youtu.be/vKFr82qnN0c?t=262
| trenning wrote:
| This fan downforce enabled EV race car with slicks on it can do a
| 0-60 in 1.4 seconds.
|
| I thinks this puts to rest the Musk claim of a 1.1 sec 0-60 Tesla
| Roadster if there still any people still hanging on to that
| fantasy.
| spullara wrote:
| They are claiming 1.9s? Where did you see 1.1?
|
| https://www.tesla.com/roadster
| petewailes wrote:
| Not the OP.
|
| You're right, it was always 1.9. They're still talking out of
| their backsides though. If the Rimac supercars can't do it
| without a fan to suck the car to the ground, Tesla sure
| can't.
|
| Without a fan you just can't get the traction you'd need.
| There's no tyre on the planet which could grip that hard.
|
| Additional detail - I suspect with a one foot rollout, on a
| VHT surface, on a hot day, in ideal conditions, they might be
| able to get down to a 1.95/1.93 sort of area. But on actual
| normal road surface, from stationary, with the tyres it comes
| with? Not a chance. I'd be astonished if they got to a 2.05.
| 1.90? Not a hope.
|
| Source - knowing far too much about tyre/road interaction.
| spullara wrote:
| Model S Plaid has been clocked at < 2s by 3rd parties so I
| don't think 1.9 flat is that farfetched for the roadster.
| petewailes wrote:
| You're not wrong, but not entirely right either.
|
| They've not done it on a road surface from standing
| start. I know a reasonable amount about the tests that
| have been done to make those numbers, and Tesla require a
| foot rollout on VHT to get a 1.99/1.98 time. That's not
| the same as from standing on tarmac or concrete.
|
| Rough rule of thumb is that starting from stopped on
| tarmac costs you about 25-.3s depending on conditions.
| phphphphp wrote:
| He made the claim on twitter:
| https://twitter.com/elonmusk/status/1395474465794838528
| ("Yes, with the SpaceX rocket thruster option package" is a
| reply to someone asking if 1.1 seconds is true).
| spullara wrote:
| That doesn't sound sarcastic at all. /s
| red369 wrote:
| I can see how Musk's comment does sound sarcastic, but I
| think the Space X package isn't generally being
| considered as a joke:
| https://www.motor1.com/news/508914/tesla-roadster-spacex-
| spe...
| tromp wrote:
| > a stupefying 1.4-second 0-60 run in less-than-ideal conditions.
|
| I don't know why they call the following less than ideal:
|
| > the manufacturer hired a jet truck to dry the back straight at
| the famed F1 circuit. There, and after doing a burnout to warm up
| the tires
|
| Perhaps they could have waited for a strong tail wind?!
|
| [EDIT: apparently it could be warmer and the road drier still]
|
| Anyway, seems they have a good shot at taking over the 0-62 mph
| in 1.461 sec record set by these guys
|
| https://techstory.in/students-of-university-of-stuttgart-mak...
|
| A road-legal version is apparently on the way
|
| https://www.autoblog.com/2022/07/01/mcmurtry-sperling-fan-ca...
| themitigating wrote:
| The track was wet and it's common practice to warm up tires
| before racing or drag racings.
|
| This number on a street legal (or technically soon to be street
| legal) car is insane. That 1.4 includes rollout compare that to
| a Tesla Plaid which does it in 2.3 seconds (the 1.99 seconds is
| only possible if you exclude rollout).
|
| The McMurtry Speirling broke the Goodwood hill climb record
| this year.
|
| https://youtu.be/5JYp9eGC3Cc
| xnx wrote:
| That video is great, and less than a minute. For anyone
| watching, be sure to catch the reactions of those standing at
| the starting line.
| aidenn0 wrote:
| That hill climb looks like a sped up Benny Hill video...
| nicowsen wrote:
| They did this in winter in England. Even if the track was dry,
| it was still far from the ideal surface temperature for
| something like this.
|
| The conditions certainly weren't aweful, but they were not
| ideal (or less-than-ideal).
| prng2021 wrote:
| Weren't awful? That's like saying a 99/100 exam score isn't
| awful, but it's not ideal either.
|
| There was no tire spin and that was so close to ideal
| conditions that I imagine the most they could shave off is a
| few hundredths of a second. Even if they couldn't, it's mind
| boggling how fast this car is.
| macmac wrote:
| So many things were far from optimal for that run. Low air
| temperature, high humidity, low track temperature, low
| traction track surface, low temperature tires (even with
| the spin, that only affects the surface and dissipates very
| quickly).
| jackmott42 wrote:
| There was no tire spin because the computers don't allow
| it. If you provide more grip the car provides more power.
| jackmott wrote:
| The track still wasnt dry, you can see the moisture
| hengheng wrote:
| "Prepared surface" is a whole thing in drag racing. I remember
| reading how Dodge got their Hellcat under 10 seconds, and it
| involved not only special tires, but also a specific gunk that
| is apparently common to spread on the tarmac, said to be sticky
| even to walk on it.
|
| Normal things in drag racing I guess, but no way they'd allow
| that in Silverstone.
| matthewmcg wrote:
| When I read "electric fan car" I thought the fans would be
| producing forward thrust to accelerate the car, not downforce.
| This raises the question--would it be more effective to
| accelerate the car this way (probably less efficient, even with
| huge aircraft style electric ducted fans) vs. putting the force
| through the wheels (limited by traction)?
| jackmott42 wrote:
| well it sucks to the ground AND blows that air out the back,
| though the thrust is negligible. The answer to your question
| though is no. It is much more efficient to push against the
| ground with the tire. In fact this sucking method is more
| efficient than a wing or other aerodynamic down-force devices.
| You might see the wing they have no go away at some point, as
| it was added to improve balance. Maybe they will figure out how
| to adjust that with the skirt or something.
| petewailes wrote:
| I could go into the physics, but in short, no. Two hard contact
| patches just grab way more than a propeller can on air.
|
| In water it'd work, but then you've made a boat and the wheels
| are irrelevant.
|
| Boats have always been capable of faster acceleration in
| theory. Problem Child, for example, did 0 to above 250mph in
| about 3.5s.
| macmac wrote:
| I think the hill climb record at Goodwood this summer was even
| more impressive. That thing looks like it is glued to the track.
| Check out a few other cars doing the climb and you will see a
| noticeable difference.
| https://www.youtube.com/watch?v=5JYp9eGC3Cc
| hef19898 wrote:
| For everyone who wants to see it in action, check out the video
| of the Goodwood hillclimb where the McMurty set the record.
| Ideally the full video with the runner ups, otherwise you would
| think the video is running at 1.5x speed.
| dghughes wrote:
| CarWow too has a good video about it
| https://www.youtube.com/watch?v=TptzkkbC1vE
| jackmott wrote:
| Never has a car elicited such emotion from the crowd, it is
| amazing to see
| kstrauser wrote:
| The video was a joy to watch. Everyone on camera was having fun
| and allowing themselves to be fully excited and enthusiastic.
| aitchnyu wrote:
| If we consider goals of future cars to emit less co2,
| microplastics, brake dust and safer, how does modern racing
| advance these goals? In my jaded view, rich guys are going faster
| and nothing trickling down to economy cars.
| LeonM wrote:
| Current generation F1 engines for example, are limited to just
| 1.6L (97 cubic inch) displacement, and teams are not allowed to
| refuel during the race. This forces engineers to design more
| efficient engines (less fuel equals less weight). Last season's
| cars were reported to achieve over 50% thermal efficiency
| (compared to ~20% for a regular road-going car) and close to
| 1000hp.
|
| Whether this technology actually trickles down to production
| vehicles is debatable. But traditionally racing has been the
| incentive for major advances to be made in efficiency,
| aerodynamics, drivetrain components, tyres etc.
| arethuza wrote:
| Worth noting that seventy years ago we had 1.5L V16 F1
| engines producing 600HP
|
| https://en.wikipedia.org/wiki/British_Racing_Motors_V16
|
| They weren't the most reliable things though....
| scarier wrote:
| I mean, in the 1980s turbo era F1 engines were putting out
| way more than that--try around 1000 hp/l!
|
| That was done with absurd levels of boost, fuel that bore
| little to no chemical resemblance to gasoline, and engines
| with a life expectancy (in qualifying trim) measured in
| single-digit laps.
|
| The advances in modern engines' efficiency and reliability
| are staggering.
|
| https://en.wikipedia.org/wiki/BMW_M12
| Rastonbury wrote:
| Think of racing as entertainment, what does tennis do for the
| world? And I think tennis is great
___________________________________________________________________
(page generated 2022-12-20 23:01 UTC)