Clarification: The discrepancy between the analysis and the actual power used was mostly because the analysis does not take rolling resistance into account.
Hear me out: *backwards* land speed racing. Use the Jag. It’s the most logical progression following everything we saw in 2022. Lovely episode as always, Matt.
Facing backwards is actually safer in a crash… So it’d vaguely make sense for a land speed racer. Other than the whole seeing where you’re going part. But they made it work in Captain Scarlet. Cameras yo.
ua-cam.com/video/S7ipFApsFec/v-deo.html This was huge in circuit racing. CVT gearboxes so it was as fast in reverse as forward. Sadly CVT went out of style so we don't get these high-tech races anymore.
Just need to make sure it sucks enough air through that radiator, and hook it up for rear-steering so that the wheel spats on the front wheels works... =p
One time the transmission on my fathers GMC Yukon gave out and the only gear he could drive in was for some reason reverse. He drove the rest of the way home (2.2 miles) backwards. It really did blow minds. The look on peoples faces who saw was priceless! 😳🤣
About airshaper... Keep in mind their pricing. It's about $54 for a single run. Not bad, but if you're doing a lot of changes and re-running that will add up fast. If you want to use their fancy optimization system, which will run your model through a ton of times and actually alter the model to optimize flow, that's about $1080, wew. If you want a yearly sub, it's 10,800 (!!!), Woah. They also have a $325 per hour consultancy thing, where a person gets on the phone and walks you through your sim run and how best to alter the model for a re-run
"Extra credit on a test you failed" 😄 Another object lesson in how to explain a complex idea in ways that a non-expert audience can understand. I have learned so much from your videos. Almost certainly nothing I'll be able to use in life, but the knowledge itself is great to grok. Link shared, liked and already subscribed - the algorithm should be satisfied...
At the very least he could do a nice video showing the difference a bunch of vortex generators would make. You've got the measuring equipment built into the car, just use some double sided tape to temporarily attach 3d printed vortex generators or other aerodynamic devices. Perhaps sand the prints and slap on some bondo to get rid of print artifacts. We just need Airshaper to sponsor the video ;)
there's a lot you can do to the front of the Jag that would be mostly invisible on casual glance: -small bellypan from the front bumper back to the front wheels, and air curtains inside the front fenders. (diverting air from between the two chrome sausage bumpers which could be a hidden duct) -block unused sections of the grille inside (blacked out, would be 'invisible') -naca ducts at the intersection of the front fenders and hood, just below the lights, for a high pressure relief zone. exit vents underneath. -controversially, bullet cap clear headlight covers. It would look like quad boobs, but you're a man so...moobs? and four, so moar moobs. I would say it would be sacrilege to mod a classic Jag but it feels like you might be a touch beyond being able to make that argument...
I like this idea. Especially the naca ducts. Even something more radical like installing a split windscreen with better geometry would help. No one but enthusiasts would know.
Love the inclusion of the green Australian Kingswood wagon...aerodynamics of a fridge, but such a ubiquitous car here! Screw the drag, aesthetics take precedent when you also have a land speed build (even if the body is still theoretically a future Matt problem). Great content as always!
The third car in the "aerofoil wedge" section is also an Australian designed and built car. Nissan Pintara Superhatch, built in Clayton, Victoria from 1989 to 1992. The "Superhatch" version was designed in Australia and actually exported to Japan because they didn't build a wagon version.
I remember when the Lotus Europa was released in Australia in about 1968/9. It had a CD of .29 (as I remember) which at the time was the best ever for a production car, displacing the Citroen DS. Things have moved forward.
Hi Matt. Julian Edgar has amazing videos on improving the aerodynamics on cars. One of his latest videos is about the drag from cooling and how porsche reduced that drag by forcing the air in front of the front wheels instead of just.... Out.
Sweet drop in of the Australian 1976 HJ Holden Kingswood Station Wagon. I owned the utility model back in tge day when youcould balance ce a long neck on the steering wheel rim and horn bar. Great for a hot drive on the Hay plain.
So how about directing some of that no longer needed air from the radiator out at a shallower angle in front of the windshield and/or to the sides behind the fenders? I suspect a lot of it used to escape downward behind the engine which could be blocked off with a sheet of metal. I think it would be really cool to improve on the Jag's aerodynamics in clever ways without hurting its looks too much.
There are a couple of period correct not too ugly things you can bolt on to improve the drag coefficient possibly. First a stone/bug shield in front of the windshield , this is a small strip of plexiglass mounted just in front of the windshield at an angle to deflect anything that might damage the glass up over the roof. You see them fitted to big rigs sometimes. Second is the trunk rack that they bolted to the top of the trunk. You could design one that looks classic but works as a spoiler. Additional changes. Blocking off most of the radiator and ducting the engine bay air into places where it will improve aerodynamics.
Bought a old 80s boxy mercedes once (W124), was very surprised to know that they were extremely aerodynamic (with the sleekest models being only 0.26 drag co) Interesting stuff.
I wonder how much difference having the sides of the engine bay open makes. In racecars they put huge efforts into getting the air from the radiators/intercoolers out from the engine bay, not just for cooling but also for airodynamics (makes the wall less of a wall and more of a air duct).
You could take the air from underneath backwards jag and duct it up through the rear mount radiator. This would make the air at the back break away more smoothly by partially filling the aero vacuum the vertical surface creates.
You absolutely need to turn the interior 180° now, work out some legal (but not visibly obvious) lighting and make that car go backward full time. You can leave the steering on what is currently the "front" axle; just reverse the direction when you work out the new linkage. It'll just take a little getting used to. I'll be watching next week's episode for your road test of this. 🙂
Another great video. Had a friend who was in college for aerodynamics and whatnot. He wanted to show that my MGB had worse aero numbers than his fiat spyder. Turns out the MG was cleaner going forward, and the fiat was cleaner going in reverse.l
Maybe you could put on some vortex generators in the back and a bug deflector for your windshield to test how much difference would they make? Both should be easy to remove if you don't like the look.
There’s a trick you didn’t mention for radiators - the drag is based on frontal area, While heat rejection is is a function of surface area and and fresh-air airflow - but it’s a decreasing multiple so you can have a large radiator at an angle to the incoming air and have the same heat rejection as a smaller radiator directly facing the airflow. You can see this applied in F1 cars (or the Veyron - I assume the Chiron does it too), where each car will have numerous relatively small inlets with diagonally facing radiators, reducing the frontal area of the car. This is because the heat rejection of modern radiators doesn’t scale well with increasing airspeed but scales better with increased surface area. You’ll find the same principle in PC CPU all-in-one water cooling units, where you get a dramatic increase in cooling performance with a larger radiator rather than increased fan speed. I’m sure someone has the equations for this, my expertise is in application here - I’ve never had to actually solve the math in advance for this.
Adding something like a spoiler lip at the back would indeed be sacrilege on this Jag, even if it helped aero. But there is one big option that would retain the overall shape while aiding aerodynamics: Hood louvers. You'll have to run more simulations to find if placing them across the top or sides (or both) will be most effective at alleviating low pressure zones and turbulence in this area. Not only would it improve aero, it would aid airflow through the radiator, and because there is no engine in the way, a secondary surface could be built to guide air upwards an out. In side view, this surface could better approximate the sloped nose of something like a Prius, but would simply exist as ducting below the louvers, and behind the radiator, so you would never see it.
9:11 - this brings the memory of the Myth Busters episode where they were not allowed to name Porsche 928 so they referred to it as "this sports car" 😄 They also proved that it was NOT more areodynamic in reverse. Good show. Also the main reason wheels are not covered is servicability and assembly complexity - which why the prototypes often feature wheel covers that do not make it to the production line cars. Duesenberg Coupé Simone Midnight Ghost anyone?? 😉
When I was young I noticed that if I stared and defocused, I could see the turbulent dust/air that cars carry with them. It only works if I relax and not focus on anything. Also, the 87-93 Mustang GT has a cd of .36-39 😁
I rememeber doing that too! Also staring at a cars wheel and blinking at the right rate you could see the wheel for a brief moment stopped, while its travelling at 100kmh
This is also true of most aircraft, which is why tailslide manouevers are usually banned. The forward drag coefficient is so low that when you reduce it further, by going backwards, it actually becomes negative… and the aircraft just zips into the lithosphere before the pilot can react.
When a bunch of guys got together and did actual windtunnel testing of the 240/260/280z years ago, they found out the stock bodied car had a drag coefficient of .471. The real alarming bit was 367 pounds of lift on the front wheels@120mph.
How about a follow up video on a vintage aerodynamic car, the 1934 Chrysler Airflow. I've seen a vintage video touting how much of a leap forward this car was and it would be interesting to see how it would perform using modern analysis. Jay Leno has one.
That clip from think flight really has me wishing to see a collaboration from you guys, maybe on the land speed body or just a video attempting to make the Jag efficient in some way. Two of my favorite socal youtube channels!
Snaps for the slime green HJ Kingswood wagon Superfast. (If it isn’t to bold to use your first name. ) I had one of those in the ute variation. Great car.
9:50 most cars will still have a fan to force air through the radiator, so even when driving in reverse for longer periods the fan will simply turn on to prevent the engine from overheating
Considering there is no radiator, all of that air could be directed out of the sides of the hood in some period correct looking vents; filling in some of that side turbulence. I reckon a well designed rear spoiler would be magnificent. Split that air!
My fluid dynamics prof used to say; "If you push fluid out of the way, something's gonna wanna fill the void. It could be the wing of a plane or the ass end of your car." He was very smart. I'm not so much.
i decided to create a car 100% out of water, without wheels. It also only moves downward and doesn't even need a road. I call it "the raindrop" it naturally is curved in the front and pointed on the rear
If you make a roll cage ocvered by a glass dome, the dome can be made to look "black mirror" while actually offering a great view out. The rear crash structure gets an under the skin upgrade. No problem as the original bonnet will offer a huge boot in the now back.
The 2+2 E-type is actually a great vehicle and gorgeous in person, plus they can be had so much cheaper than the previous ones. Especially fun with a 6-speed transmission shoehorned in there, one of ours idles at like 80mph in 6th, lol.
I take it thats a t56? My friends car has one of those, says in the manual you arent supposed to use 6th below 160kmh 😂 (its doing like 1200rpm at 100kmh)
This message is for future Matt; I love your new video! Now for current Matt; I think you could make watching paint dry seem funny and somehow witty. It's magic. And like all magic there is plenty of effort needed to make it seem effortless. In a word: masterful.
Happened to stop at 12:48 What i see is an ad, for someone but that page seems to not have the name of the service so if you didn't pick it up from the spoken word.... Just a hint, maybe that name should be present somewhere in text form for the entire segment.
Nice HJ Holden @10:35. BTW I worked at the Elizabeth GMH plant in the summer of 78-79, on the production line building the HZ Holden. My car has better drag driving backwards? I doubt it, it is a Discovery 2
well, now Matt, here is an idea. make front wheel coverings that move with the wheels, so when you go straight you get the full benefit. at low speed, like pulling into parking space drag is not your problem. does not even have to mount directly to the suspension, maybe just put something that pushes the covers when the tire gets close, maybe springloaded? or a stepper motor with some programming? if it really makes a difference it should be totally worth it on trips. Much of the rad could be sealed off, too. no reason to invite a ton of air under the hood for no reason.
Aw I was really hoping you’d find a large enough parking lot to get the Jaaag up to speed in reverse and try to compare it to the consumption going forwards. Doesn’t need to be highway speed, but at least the motor should be capable of that. Regarding the aero design notes, I’m pretty disappointed that automakers haven’t yet taken advantage of EV packaging to make extremely cab forward designs that actually have all the right shapes in the right places. The closest is stuff like the ID.Buzz and Canoo but they have a stubby front end and a far away windshield for cargo reasons. Now I want to see a Buzz with kamm tail and some cD numbers. I’m excited to see how they can innovate when they move beyond expected shapes in car design. I guess stuff like crossover coupes and ultra efficient designs like the XL1, lightspeed one, and EQXX are a step in the right direction by why stop there? Also side note, I really liked Jason Camissa’s ELI5 explanation of the coefficient of drag - he said it’s like how much smaller an object looks to the wind. So a car twice the frontal area but half the cD of another look the same size to the wind.
Ignoring any issues about crash safety, cab forward designs aren't the most fun to drive and there's a bit of getting used to steering something where the wheel's are under your butt.
you could do some bits to make it better... transparent spoiler, few degrees of angle on the grill, closing up some holes, trimless windows, etc. would be very cool in the end
As someone who recently graduated (during covid) and is working in the engineering field, you are giving me lots of motivation for the future! I wish to some day start a project car (which I have been brain storming since high school) and put all the engineering knowledge to the test! Also, am new to your channel! YT randomly recommended me one of your vids and now I am subbed!
You know, some appropriately subtle "shark fins" on the cabin roof might actually look quite nice; In terms of style, think the rear diffuser from some of the less gaudy BMW M cars, but upside down on the roof. Given everything else going on in the rear that destroys the vehicle's efficiency these probably wouldn't do enough to be worth all the effort, but with the Tesla wheels and everything, that crossover of modern and antique is already kinda-sorta part of the vehicle's schtick and could actually be quite fitting...
Very educational. I know that teaching is a thankless job, but..... you would be inspirational to 11th & 12th grade science or math students. The teachers that I learned from and remember the most, taught with humor. You are great at it. Cheers.
Very surprised that the windshield going in reverse isn't a low pressure zone. I recall Mythbusters doing this a long time ago with the Porsche 944 (or maybe it was a 928) and they used a wind tunnel. I recall seeing either a low pressure zone or a lot of turbulence around the windshield when in reverse. They concluded that the Porsche wasn't more aerodynamic in reverse. You can do the same test they did. 3d print the car and submerge it in flowing water. I think they used oats, but something finer like glitter would probably show up better? Either way, Great Video!
I’d suggest making some plastic covers for the engines on the underside. I have no idea what what I’m talking about but I’d say it could help with the range a bit
Perhaps some covert airflow ducting inside the front of the Jag? Inlet through the grill, outlet as small slots along the side of the "engine cover" to disrupt all that bad air coming off the headlights. Could be done very subtly and not change the look.
How much drag can you loose with holes, luvers, or removal(SoCal speedster)? How much radiator does the jag accually need? Could controlled vents/holes/flaps improve handling/drag to something close to a car today? Summit had an articile about The Brick(Fastest Astro Van), they did some pretty cleaver stuff you to can do. Great video, all hail the algorithm.
Have you seen those round projector retrofit headlights that have the near spherical lenses over the front of them? I think they were made for jeeps so the huge projecter unit could actually fit. Anyway, they stuck out real far up front with a round profile..... I wonder if those would help a lot with the noise and turbulence with the headlights by replacing the flat blunt face with something more streamlined. Also, what about puting some close-able slats on the grille that can open/close when the system actually needs cooling?
I'm a fan of high pressure cooling systems that just pump to under body skins and back. A few planes had them. Seems they thought a radiator sticking out was gonna slow them down or something.
The best thing about the E-Type 2+2 is that it is easier to fit taller drivers comfortably into one than a E-Type FHC or OTS. This wouldn't be a problem for a reasonably sized person like yourself but those of us who were born with a little too much stature REALLY appreciate that sort of thing. That's the main reason why I purchased a Chrysler PT Cruiser instead of a Toyota Matrix.
Another good example is the typical commercial roof storage box that goes on your roof rack. A number have people have proven that it’s aerodynamic properties are all wrong. Put it on “backwards” and the drag is reduced. You can see this immediately in our Tesla with reduced power consumption having the roof box facing the wrong way, ie: less additional drag than having the box face the way it’s designed to.
@03:08 doesn't the air go through the radiator grill down and out? I'm uncertain if it's the worst offender there. It would have to calculated as an opening in the front for modeling to be correct, unless you have closed it off from intake. If it is closed off to keep water and debris out, then extending the V shape in front might help.
Clarification: The discrepancy between the analysis and the actual power used was mostly because the analysis does not take rolling resistance into account.
Pixar moms being incredibly unaerodynamic is something I didn't expect to hear this early in the year
Something I never expected to find in a superfastmatt video.
Then again, that's exactly what makes it a superfastmatt video.
Yeah, that’s usually more of a September/October sort of deal.
LOL!😆
I will never NOT think of Cardi B when I see this car and cars of that era. Congratulations Matt, you changed the algorithm.
Only when they're going forward
Hear me out: *backwards* land speed racing. Use the Jag. It’s the most logical progression following everything we saw in 2022.
Lovely episode as always, Matt.
If I combined all my projects into one project, I'd have so much free time. Time for more projects!
Facing backwards is actually safer in a crash… So it’d vaguely make sense for a land speed racer. Other than the whole seeing where you’re going part. But they made it work in Captain Scarlet. Cameras yo.
@@Jonathan_Doe_ Tom Scott tried that last year. It doesn't work well. Check his video on it titled "Can you really drive while facing backwards".
ua-cam.com/video/S7ipFApsFec/v-deo.html
This was huge in circuit racing. CVT gearboxes so it was as fast in reverse as forward.
Sadly CVT went out of style so we don't get these high-tech races anymore.
Before you try backwards land speed racing please drive any fork truck forks forward at 15-20 MPH.
For the experience.
For giving the answer in the intro before elaborating, instead of making me wait. Now I will watch the whole thing.
"Like getting extra credit on a test you failed." Great line, Matt - I love your videos!
that's almost British in expression. 😉
It's getting serious when Ron shows up... LOL.
For some reason it makes me happy knowing that Ron watches Matt as well :)
I know this exact feeling, funny enough.
This comment from Ron is proof that you’ve made it Matt… congrats.
The Jag turns heads for sure. If you built it to drive back forwards, it would blow minds. I do love this Jag.
"back forwards" 🤣
Blowing minds aint a good thing so forward driving it is.
Just need to make sure it sucks enough air through that radiator, and hook it up for rear-steering so that the wheel spats on the front wheels works... =p
One time the transmission on my fathers GMC Yukon gave out and the only gear he could drive in was for some reason reverse. He drove the rest of the way home (2.2 miles) backwards. It really did blow minds. The look on peoples faces who saw was priceless! 😳🤣
It is absolutely hideous what hes done to it but the video is good....
About airshaper...
Keep in mind their pricing. It's about $54 for a single run. Not bad, but if you're doing a lot of changes and re-running that will add up fast.
If you want to use their fancy optimization system, which will run your model through a ton of times and actually alter the model to optimize flow, that's about $1080, wew.
If you want a yearly sub, it's 10,800 (!!!), Woah.
They also have a $325 per hour consultancy thing, where a person gets on the phone and walks you through your sim run and how best to alter the model for a re-run
Slight detail. 😂
Wtf
"Extra credit on a test you failed" 😄 Another object lesson in how to explain a complex idea in ways that a non-expert audience can understand. I have learned so much from your videos. Almost certainly nothing I'll be able to use in life, but the knowledge itself is great to grok. Link shared, liked and already subscribed - the algorithm should be satisfied...
1:51 the transition from being attached to detached can be really bad for band-aids as well.
Yeah try it with a wife gets expensive quickly like half of your stuff expensively right quick
@@jeremyhanna3852 what?
@@LeafBoye the transition of being attached and unattached
@@LeafBoyeIt's a divorce joke.
I think some vortex generators could actually look sick as hell on there, very batmobile. It’s worth a shot!
Yeah maybe do them in a "period correct" way for a plane of that era, hand formed and riveted and such.
sick...
At the very least he could do a nice video showing the difference a bunch of vortex generators would make. You've got the measuring equipment built into the car, just use some double sided tape to temporarily attach 3d printed vortex generators or other aerodynamic devices. Perhaps sand the prints and slap on some bondo to get rid of print artifacts.
We just need Airshaper to sponsor the video ;)
The rims are already weird, it’ll look more like a ricer project than a batmobile
@@JoranGroothengel ב''ה, magnet-mount(s)
there's a lot you can do to the front of the Jag that would be mostly invisible on casual glance:
-small bellypan from the front bumper back to the front wheels, and air curtains inside the front fenders. (diverting air from between the two chrome sausage bumpers which could be a hidden duct)
-block unused sections of the grille inside (blacked out, would be 'invisible')
-naca ducts at the intersection of the front fenders and hood, just below the lights, for a high pressure relief zone. exit vents underneath.
-controversially, bullet cap clear headlight covers. It would look like quad boobs, but you're a man so...moobs? and four, so moar moobs.
I would say it would be sacrilege to mod a classic Jag but it feels like you might be a touch beyond being able to make that argument...
It's not about sacrilege, it's about style. That's why he used the jag body. Ruining the looks defeats the purpose of using the body.
It's already modded. The engine went out for an electric unit.
@@shawa666 i guess my irony doesn't translate
I like this idea. Especially the naca ducts. Even something more radical like installing a split windscreen with better geometry would help. No one but enthusiasts would know.
@@sepg5084 "ruining the looks defeats the purpose" I guess you missed the hideous Tesla wheels
7:55 ‘extra credit right on a test you failed.’ yeah…been there. 😅
That part hit me just a little bit too close to home 😔
Loved seeing the Holden Kingswood wagon at 10:34 😀
ua-cam.com/video/h1ZUm4q5OfQ/v-deo.html
Came here to say the same thing! 👍
Love the inclusion of the green Australian Kingswood wagon...aerodynamics of a fridge, but such a ubiquitous car here! Screw the drag, aesthetics take precedent when you also have a land speed build (even if the body is still theoretically a future Matt problem).
Great content as always!
The third car in the "aerofoil wedge" section is also an Australian designed and built car. Nissan Pintara Superhatch, built in Clayton, Victoria from 1989 to 1992.
The "Superhatch" version was designed in Australia and actually exported to Japan because they didn't build a wagon version.
I remember when the Lotus Europa was released in Australia in about 1968/9. It had a CD of .29 (as I remember) which at the time was the best ever for a production car, displacing the Citroen DS. Things have moved forward.
Hi Matt.
Julian Edgar has amazing videos on improving the aerodynamics on cars.
One of his latest videos is about the drag from cooling and how porsche reduced that drag by forcing the air in front of the front wheels instead of just.... Out.
Sweet drop in of the Australian 1976 HJ Holden Kingswood Station Wagon. I owned the utility model back in tge day when youcould balance ce a long neck on the steering wheel rim and horn bar. Great for a hot drive on the Hay plain.
So how about directing some of that no longer needed air from the radiator out at a shallower angle in front of the windshield and/or to the sides behind the fenders? I suspect a lot of it used to escape downward behind the engine which could be blocked off with a sheet of metal. I think it would be really cool to improve on the Jag's aerodynamics in clever ways without hurting its looks too much.
this
that
and the other thing
I'm guessing hood vents would annoy the purists even more than the electric conversion
Matt should do it!
Definitely chromed plastic if he does
There are a couple of period correct not too ugly things you can bolt on to improve the drag coefficient possibly.
First a stone/bug shield in front of the windshield , this is a small strip of plexiglass mounted just in front of the windshield at an angle to deflect anything that might damage the glass up over the roof. You see them fitted to big rigs sometimes.
Second is the trunk rack that they bolted to the top of the trunk. You could design one that looks classic but works as a spoiler.
Additional changes.
Blocking off most of the radiator and ducting the engine bay air into places where it will improve aerodynamics.
Deflect-a-Shield! Originally developed as a gimmick to sell to the rubes but later discovered to actually work at keeping bugs off your windshield.
Bought a old 80s boxy mercedes once (W124), was very surprised to know that they were extremely aerodynamic (with the sleekest models being only 0.26 drag co) Interesting stuff.
I wonder how much difference having the sides of the engine bay open makes. In racecars they put huge efforts into getting the air from the radiators/intercoolers out from the engine bay, not just for cooling but also for airodynamics (makes the wall less of a wall and more of a air duct).
You could take the air from underneath backwards jag and duct it up through the rear mount radiator. This would make the air at the back break away more smoothly by partially filling the aero vacuum the vertical surface creates.
You absolutely need to turn the interior 180° now, work out some legal (but not visibly obvious) lighting and make that car go backward full time. You can leave the steering on what is currently the "front" axle; just reverse the direction when you work out the new linkage. It'll just take a little getting used to. I'll be watching next week's episode for your road test of this. 🙂
Another great video. Had a friend who was in college for aerodynamics and whatnot. He wanted to show that my MGB had worse aero numbers than his fiat spyder. Turns out the MG was cleaner going forward, and the fiat was cleaner going in reverse.l
Maybe you could put on some vortex generators in the back and a bug deflector for your windshield to test how much difference would they make? Both should be easy to remove if you don't like the look.
There’s a trick you didn’t mention for radiators - the drag is based on frontal area, While heat rejection is is a function of surface area and and fresh-air airflow - but it’s a decreasing multiple so you can have a large radiator at an angle to the incoming air and have the same heat rejection as a smaller radiator directly facing the airflow. You can see this applied in F1 cars (or the Veyron - I assume the Chiron does it too), where each car will have numerous relatively small inlets with diagonally facing radiators, reducing the frontal area of the car. This is because the heat rejection of modern radiators doesn’t scale well with increasing airspeed but scales better with increased surface area. You’ll find the same principle in PC CPU all-in-one water cooling units, where you get a dramatic increase in cooling performance with a larger radiator rather than increased fan speed.
I’m sure someone has the equations for this, my expertise is in application here - I’ve never had to actually solve the math in advance for this.
10:35 paying tribute to the Holden Kingswood Station wagon! always good when we get a look in. Thanks Matt.
Adding something like a spoiler lip at the back would indeed be sacrilege on this Jag, even if it helped aero. But there is one big option that would retain the overall shape while aiding aerodynamics: Hood louvers. You'll have to run more simulations to find if placing them across the top or sides (or both) will be most effective at alleviating low pressure zones and turbulence in this area. Not only would it improve aero, it would aid airflow through the radiator, and because there is no engine in the way, a secondary surface could be built to guide air upwards an out. In side view, this surface could better approximate the sloped nose of something like a Prius, but would simply exist as ducting below the louvers, and behind the radiator, so you would never see it.
9:11 - this brings the memory of the Myth Busters episode where they were not allowed to name Porsche 928 so they referred to it as "this sports car" 😄 They also proved that it was NOT more areodynamic in reverse. Good show. Also the main reason wheels are not covered is servicability and assembly complexity - which why the prototypes often feature wheel covers that do not make it to the production line cars. Duesenberg Coupé Simone Midnight Ghost anyone?? 😉
I found your channel by looking for videos about aerodynamics, loved it, love this video, keep up the good work!
When I was young I noticed that if I stared and defocused, I could see the turbulent dust/air that cars carry with them. It only works if I relax and not focus on anything. Also, the 87-93 Mustang GT has a cd of .36-39 😁
I rememeber doing that too! Also staring at a cars wheel and blinking at the right rate you could see the wheel for a brief moment stopped, while its travelling at 100kmh
This is also true of most aircraft, which is why tailslide manouevers are usually banned. The forward drag coefficient is so low that when you reduce it further, by going backwards, it actually becomes negative… and the aircraft just zips into the lithosphere before the pilot can react.
Underrated comment
When a bunch of guys got together and did actual windtunnel testing of the 240/260/280z years ago, they found out the stock bodied car had a drag coefficient of .471. The real alarming bit was 367 pounds of lift on the front wheels@120mph.
How about a follow up video on a vintage aerodynamic car, the 1934 Chrysler Airflow. I've seen a vintage video touting how much of a leap forward this car was and it would be interesting to see how it would perform using modern analysis. Jay Leno has one.
I have one too..😊
This project brings me so many smiles. Just another continuation of awesomeness
I love that the jag is more aerodynamic than the empire state building.
That clip from think flight really has me wishing to see a collaboration from you guys, maybe on the land speed body or just a video attempting to make the Jag efficient in some way. Two of my favorite socal youtube channels!
And here I was thinking this video was going to be about 2 stroke Saabs and Trabants driving in reverse with four gears. I was wrong.
This must be somehow related to a video I watched lately about a bug in a racing vide game where you would drive faster if you drive backwards.
"...like getting the extra credit question right on a test you failed." Some of your throwaway lines are gold.
Oh, aerodynamics... it feels like the more I study about it, the less I know. And I love it!
At 10:35 you show a classic example of an Australian Holden HJ Kingswood Station Wagon. All the aerodynamics of a house brick but what a great car 👍
0:30 I know that stretch of road well. I grew up going up and down that mountain all the time.
I just adore your speech/behavior thingie. Nice to know you. Not really you but the part of you that you wanted to show. Nice work!
As usual with your content, awesome video! I just love your plain dry humor while explaining interesting stuff :D
Greetings from Germany
Snaps for the slime green HJ Kingswood wagon Superfast. (If it isn’t to bold to use your first name. ) I had one of those in the ute variation. Great car.
9:50 most cars will still have a fan to force air through the radiator, so even when driving in reverse for longer periods the fan will simply turn on to prevent the engine from overheating
Your procrastination skills are truly unmatched.
Considering there is no radiator, all of that air could be directed out of the sides of the hood in some period correct looking vents; filling in some of that side turbulence.
I reckon a well designed rear spoiler would be magnificent. Split that air!
I love the crankshaft lamp in the background :) I wonder what absolute chad build it. Regardless of that, still probably more aerodynamic than the jag
Can't tell if this is sarcasm or not, but he built it in a different episode... >_>
My fluid dynamics prof used to say; "If you push fluid out of the way, something's gonna wanna fill the void. It could be the wing of a plane or the ass end of your car." He was very smart. I'm not so much.
I'd like to see this done on one of those 50's bathtub Nash's where the front wheels were 2/3 covered.
AirShaper is an amazing tool. Thank you for showcasing it and the features.
i decided to create a car 100% out of water, without wheels. It also only moves downward and doesn't even need a road. I call it "the raindrop" it naturally is curved in the front and pointed on the rear
If you make a roll cage ocvered by a glass dome, the dome can be made to look "black mirror" while actually offering a great view out. The rear crash structure gets an under the skin upgrade. No problem as the original bonnet will offer a huge boot in the now back.
The 2+2 E-type is actually a great vehicle and gorgeous in person, plus they can be had so much cheaper than the previous ones. Especially fun with a 6-speed transmission shoehorned in there, one of ours idles at like 80mph in 6th, lol.
I take it thats a t56? My friends car has one of those, says in the manual you arent supposed to use 6th below 160kmh 😂 (its doing like 1200rpm at 100kmh)
This message is for future Matt; I love your new video!
Now for current Matt; I think you could make watching paint dry seem funny and somehow witty. It's magic. And like all magic there is plenty of effort needed to make it seem effortless. In a word: masterful.
next project, calculating how to reduce road spray, which seems greatly overlooked in car & truck design.
So you did this analysis to delay building the body of the land speed car. Good job.
Happened to stop at 12:48 What i see is an ad, for someone but that page seems to not have the name of the service so if you didn't pick it up from the spoken word.... Just a hint, maybe that name should be present somewhere in text form for the entire segment.
Kingswood FTW @13:11. Nice stuff Matt!
Stainless steel "sun shade" on the rear window
Nice HJ Holden @10:35. BTW I worked at the Elizabeth GMH plant in the summer of 78-79, on the production line building the HZ Holden. My car has better drag driving backwards? I doubt it, it is a Discovery 2
Was I the only one thinking some of those PERIOD CORRECT aircraft aero bits would look really neat?
You're a real UA-cam ! I subscribed, you explain really well!
well, now Matt, here is an idea. make front wheel coverings that move with the wheels, so when you go straight you get the full benefit. at low speed, like pulling into parking space drag is not your problem. does not even have to mount directly to the suspension, maybe just put something that pushes the covers when the tire gets close, maybe springloaded? or a stepper motor with some programming? if it really makes a difference it should be totally worth it on trips. Much of the rad could be sealed off, too. no reason to invite a ton of air under the hood for no reason.
Aw I was really hoping you’d find a large enough parking lot to get the Jaaag up to speed in reverse and try to compare it to the consumption going forwards. Doesn’t need to be highway speed, but at least the motor should be capable of that.
Regarding the aero design notes, I’m pretty disappointed that automakers haven’t yet taken advantage of EV packaging to make extremely cab forward designs that actually have all the right shapes in the right places. The closest is stuff like the ID.Buzz and Canoo but they have a stubby front end and a far away windshield for cargo reasons. Now I want to see a Buzz with kamm tail and some cD numbers.
I’m excited to see how they can innovate when they move beyond expected shapes in car design. I guess stuff like crossover coupes and ultra efficient designs like the XL1, lightspeed one, and EQXX are a step in the right direction by why stop there?
Also side note, I really liked Jason Camissa’s ELI5 explanation of the coefficient of drag - he said it’s like how much smaller an object looks to the wind. So a car twice the frontal area but half the cD of another look the same size to the wind.
Ignoring any issues about crash safety, cab forward designs aren't the most fun to drive and there's a bit of getting used to steering something where the wheel's are under your butt.
you could do some bits to make it better...
transparent spoiler, few degrees of angle on the grill, closing up some holes, trimless windows, etc. would be very cool in the end
As someone who recently graduated (during covid) and is working in the engineering field, you are giving me lots of motivation for the future! I wish to some day start a project car (which I have been brain storming since high school) and put all the engineering knowledge to the test!
Also, am new to your channel! YT randomly recommended me one of your vids and now I am subbed!
You know, some appropriately subtle "shark fins" on the cabin roof might actually look quite nice; In terms of style, think the rear diffuser from some of the less gaudy BMW M cars, but upside down on the roof. Given everything else going on in the rear that destroys the vehicle's efficiency these probably wouldn't do enough to be worth all the effort, but with the Tesla wheels and everything, that crossover of modern and antique is already kinda-sorta part of the vehicle's schtick and could actually be quite fitting...
That red XK120 (3:23) is a thing of unearthly beauty! I want that in my home so I can just sit and look at it!
that check engine light in the back reminds me of my BMW
Did not expect to see an old Kingswood here.
Upvote for the algorithm. All hail the algorithm.
Very educational. I know that teaching is a thankless job, but..... you would be inspirational to 11th & 12th grade science or math students. The teachers that I learned from and remember the most, taught with humor. You are great at it. Cheers.
If only being more aerodynamic in reverse was the only problem with the Austin Allegro, but...
Great video Matt.
You know what needs to be done Matt. Just do it!
Mount the seats in reverse, and finish the job you started!
Pleaaase
The cars I drive have the aerodynamics of a large brick. Honda Element and Ford E350 van.
My high-horse is still intact because my 1999 Lexus has a drag coefficient of 0.29. lol great video!
Very surprised that the windshield going in reverse isn't a low pressure zone. I recall Mythbusters doing this a long time ago with the Porsche 944 (or maybe it was a 928) and they used a wind tunnel. I recall seeing either a low pressure zone or a lot of turbulence around the windshield when in reverse. They concluded that the Porsche wasn't more aerodynamic in reverse.
You can do the same test they did. 3d print the car and submerge it in flowing water. I think they used oats, but something finer like glitter would probably show up better?
Either way, Great Video!
thanks for the airshaper recomendation. thats really helpful and thanks for the laughs love your humour man
I’d suggest making some plastic covers for the engines on the underside. I have no idea what what I’m talking about but I’d say it could help with the range a bit
Perhaps some covert airflow ducting inside the front of the Jag? Inlet through the grill, outlet as small slots along the side of the "engine cover" to disrupt all that bad air coming off the headlights. Could be done very subtly and not change the look.
So a Toyota Hiace or Previa with some aero flair in the rear seems to be the obvious platform of choice.
How much drag can you loose with holes, luvers, or removal(SoCal speedster)? How much radiator does the jag accually need? Could controlled vents/holes/flaps improve handling/drag to something close to a car today? Summit had an articile about The Brick(Fastest Astro Van), they did some pretty cleaver stuff you to can do. Great video, all hail the algorithm.
Watching your radiator rant, VW Beetle laughing noises...
Have you seen those round projector retrofit headlights that have the near spherical lenses over the front of them? I think they were made for jeeps so the huge projecter unit could actually fit. Anyway, they stuck out real far up front with a round profile..... I wonder if those would help a lot with the noise and turbulence with the headlights by replacing the flat blunt face with something more streamlined. Also, what about puting some close-able slats on the grille that can open/close when the system actually needs cooling?
I'm a fan of high pressure cooling systems that just pump to under body skins and back. A few planes had them. Seems they thought a radiator sticking out was gonna slow them down or something.
A few models use fuel from the wing tank to cool the avionics then pump it back. At altitude this works well. At sea level on a hot day it’s “just ok”
You're videos are awesome. Happy I found your channel.
8:55 this is how you successfully sell a bad joke while talking i to the camera all alone
how did this man learn so much comedic timing?
"I was right." *high five*
"This must be why the British drive on the other side of the road"
Sir I'm gonna need that high-five back lol
The best thing about the E-Type 2+2 is that it is easier to fit taller drivers comfortably into one than a E-Type FHC or OTS. This wouldn't be a problem for a reasonably sized person like yourself but those of us who were born with a little too much stature REALLY appreciate that sort of thing. That's the main reason why I purchased a Chrysler PT Cruiser instead of a Toyota Matrix.
Another good example is the typical commercial roof storage box that goes on your roof rack. A number have people have proven that it’s aerodynamic properties are all wrong. Put it on “backwards” and the drag is reduced.
You can see this immediately in our Tesla with reduced power consumption having the roof box facing the wrong way, ie: less additional drag than having the box face the way it’s designed to.
I was expecting Dutch backwards racing, but was pleasantly surprised.
Cool video, and congratulations on tricking me into watching a 13min commercial for Airshaper.
@03:08 doesn't the air go through the radiator grill down and out? I'm uncertain if it's the worst offender there. It would have to calculated as an opening in the front for modeling to be correct, unless you have closed it off from intake. If it is closed off to keep water and debris out, then extending the V shape in front might help.
A bonnet mounted wind deflector and a few ducts that alleviate accumulated pressure from the front cross section would improve the jags drag
I'm looking forward (or is that backwards) to you mounting the steering wheel in the back seat
Can you perhaps make a video about common DOs and DON'Ts, when creating your DIY aero?
wow, the aerodynamics makes that much difference on the energy economy (mileage)
once again - thank you!