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I'm no expert on cars but according to this article it seems like a "fan car" uses fans to pull air in from under the car to create down force rather than as a
by jccalhoun 4y ago
I'm no expert on cars but according to this article it seems like a "fan car" uses fans to pull air in from under the car to create down force rather than as a primary means of propulsion. https://electrek.co/2022/06/26/watch-electric-fan-car-record-goodwood-hill-climb/ https://electrek.co/2022/06/26/watch-electric-fan-car-record...
- eptcyka 4y agoThat's exactly right, the term usually refers to cars that use fans to generate vacuum for better grip rather than propulsion to go faster. Cars today can easily go super fast in a straight line, the hard bit is putting that power down in corners.
- masklinn 4y ago> the hard bit is putting that power down in corners. Or even just getting it from tyres to ground. Traction control exists to avoid the car just spinning its wheels in place as it’s completely lost grip. At high speed downforce can do the job, but at low speeds not so much.
- BizarroLand 4y agoHow scary would it be to be in one of those 1,400+ horsepower supercars and to hit the gas just to immediately see all four wheels start spitting smoke as they spin in place and start abrasively cutting through the asphalt?
- throwaway0a5e 4y agoFour wheel burnouts from a roll aren't that impressive from inside the vehicle. It's basically like being on "high traction" ice but with more noise. The vehicle mostly continues doing whatever it was already doing before you stomped on it.
- masklinn 4y ago> How scary would it be to be in one of those 1,400+ horsepower supercars and to hit the gas just to immediately see all four wheels start spitting smoke Not very, unless the car suddenly gets a patch of grip and launches you into a tree. > to hit the gas just to immediately see all four wheels start spitting smoke as they spin in place and start abrasively cutting through the asphalt? You'd have to wear down the entire tyre first, which isn't going to happen unless you're already at the thread (though supercar tyres do wear down very quickly). Tyre rubber is much, much softer than asphalt, and for good grip you want pretty soft rubber. By the accounts I've seen, even cold F1 tyres feel sticky. And drag tyres outright crinkle on takeoff.
- lstodd 4y agoBased on experiences with 72hp Suzuki SV650 all you need to do is grip the front brake and give it some gas. Digs asphalt at about 5mm/sec just fine. The tire gets totalled pretty fast too. So it's not rubber being too soft.
- pengaru 4y agoApparently you've never walked on hot asphalt or been a hooligan doing donuts and/or burnouts in asphalt parking lots. The tire rubber and asphalt binders/tar basically become one and the gravel comes along for the ride caught in the crossfire.
- SECProto 4y agoI've seen both (as I work in civil engineering). That is all dependant on the asphalt mix. Parking lots are usually not done with a proper performance graded asphalt, so they'll deteriorate very easily under strenuous loading conditions. Roads (in well-regulated jurisdictions) use strong asphalt mixes with a lot of large granular aggregate and a lot less asphaltic content (and asphalt that's stable at higher temperatures). This makes roads a lot tougher in these loading conditions, but also tough (and therefore expensive) to put down - need to roll it fast while its still hot, with both steel drum rollers and rubber tyre rollers. Not saying they can't be damaged, just that a parking lot is a poor comparison
- karlkatzke 4y agoIt's scary enough in a 400hp/3600lbs RWD car. Even with traction control enabled, the car likes shaking it's ass any time you tap the gas and turning the wheel on anything remotely slick with power in will break the traction wheels loose.
- iancmceachern 4y agoHence the fans sucking it to the tarmac giving it more traction
- _carbyau_ 4y agoKen Block Hoonicorn : https://www.youtube.com/watch?v=C7Tl7Zn-KRE https://www.youtube.com/watch?v=C7Tl7Zn-KRE The V2 version of the hoonicorn is about 1400hp and he does spend most of the time smoking tyres. But the asphalt is mostly fine. It's a lot tougher than rubber.
- chasd00 4y agoIt would be scarier if the tires didn’t break loose. Have you ever seen a top fuel dragster in real life? It’s a surreal sound and site.
- ortusdux 4y agoThe 3rd paragraph in the link also explains that.
- jccalhoun 4y agoAh! I somehow missed that paragraph!
- fatboy 4y agoThanks for that. I'd taken it to mean it was propelled by fans and couldn't figure out how that could possibly work. This linked article on the road legal version confirms what you say in one of the image captions: https://www.autocar.co.uk/car-news/new-cars/mcmurtry-launch-road-legal-version-speirling-fan-car https://www.autocar.co.uk/car-news/new-cars/mcmurtry-launch-... "It will feature a track mode, which will turn on the downforce-creating fan"
- btilly 4y agoThat is also the purpose of the wing on the back of the car. To generate more downwards force at speed.
- jeffbee 4y agoRight, but the wing doesn't start to work until you hit serious speeds, whereas the fan gives the car extreme traction at launch, which is pretty important in a race that only lasts 30 seconds, especially when your electric car has ~infinite torque.
- ht85 4y agoAero also has the issue of creating a ton of drag. An f1 at 300kph will decelerate around 1g if you lift off the throttle.
- jeffbee 4y agoDid you see Pastrana's ridiculous Subaru with active aero? It puts the wings away when they're dragging and they pop back up when the downforce and/or drag is wanted.
- ht85 4y agoThanks for this, I had just seen a couple highlights, just watched it and it is absolutely ridiculous. Amazing :D
- jackmott42 4y agoThe wing starts to work immediately. Just not much. This is a pedantic but important point. Even low speed motoring events aero can be very very important if sufficiently large wings are allowed. Aerodynamic gear for cyclists is advantageous even if you are a slow cyclist, etc.
- loeg 4y agoPopular "wisdom" in cycling is that aerodynamics are not a factor below 10 mph and not much of one at 15. It becomes pretty noticeable in the 15-20+ mph range (increasing with the cube of speed, or something like that).
- cjbgkagh 4y agoIf you’re not going to use grip on the road for propulsion you might as well make an airplane.
- Bendy 4y agoFrom an engineering perspective, racing cars are much closer to aircraft than they are to road cars; they just have their wings upside-down.
- cjbgkagh 4y agoTotally, but I still got downvoted a bunch... Using air for propulsion only makes sense if you're saving weight by which point you're better off cornering with wings instead of dragging wheels around with you.
- blendergeek 4y agoThese fans are to create _down_ force to increase the "weight" of the car.
- deleted 4y ago[deleted]
- GuB-42 4y agoWith the difference that they are typically not allowed to have mobile aerodynamic surfaces. That's why fan cars can be considered cheating. The fan is made of mobile aerodynamic surfaces. The Brabham BT46B try to circumvent the rules by saying their fan was a cooling fan, it didn't work. If you allow mobile aerodynamic surfaces, indeed, you are going to have aircraft. It is easy to imagine a car with actual wings, with flaps, ailerons and elevators.
- MrFoof 4y agoExactly this. One of the bigger “fans” of them — Gordon Murray — is actually producing a road legal one. The T.50, which is Gordon Murray’s attempt to “revisit” the McLaren F1 and do everything he couldn’t do (or hadn’t yet realized was possible) back in the 1990s: https://youtu.be/NT8PMXCMrsM https://youtu.be/NT8PMXCMrsM For those who aren’t aware, Harry Metcalfe was the founder of EVO magazine and had an outsized behind the scenes influence of Top Gear’s new format in the early 2000s. While Gordon sticks to some of his script, the two get VERY nerdy at points digging into all sorts of non-obvious minutiae and detail. 53 minutes is a lot, but by far it’s the best interview about the car by a large margin. Harry is also a very big EV and renewable electricity nerd, and loves digging into those topics with tons of research.
- jackmott42 4y agothe T.50 has a fan, and it is used for aerodynamic benefit, but it does so by helping speed up air through the under car diffuser, which allows them to use a more aggressive diffuser than would otherwise work. It all adds up to a modest downforce improvement and/or drag reduction. The McMurtry by comparison is more like the old F1 fan car, in that it is literally sucking itself down to the road, with tons of force, with a skirt and so on.
- MrFoof 4y agoYep. As Gordon said about the Brabham, the McMurty is, “more of a blunt instrument.” When I watched it do the hill climb I was thinking of all the drivers they might’ve approached, and thought that if Mark Webber hadn’t hung it up a few years ago he would’ve, “noped out” of that conversation immediately given his history of flying for Mercedes in the beginning of his career.
- rjvs 4y agoPlus that time when he flew his Red Bull at Valencia. Definitely the F1 driver with the most air time... so maybe the idea of a car that is actively pushing into the ground (instead of passively with wings/diffusers) would appeal.
- ummonk 4y agoRight and it’s specifically used for cornering downforce, since the coefficient of friction isn’t high enough to justify generating downforce like this in a drag race.
- olliej 4y agoI went to the article wondering if it was about a record using a class of cars driver by fans (thinking cartoon style giant fan on the roof :D)
- lynguist 4y agoGran Turismo 5 players will remember the Chaparral 2J Race Car '70 (a real race car with two giant fans on the back which was immediately declared illegal after protests of other car makers) and the fictional Red Bull X1/X2014 fan cars. I’m impressed that this video game technology comes back!
- Shorel 4y agoThis kind of fan was F1 technology back in 1978. Check out the Brabham car that won on its debut at the Swedish Grand Prix.