Funny story, a few years ago my now deceased Nana came down to visit with her son and one granddaughter in her new to her Subaru. The plain one not the WRC or WRX, anyway I noticed the wing on the boot lid and commented; "Did the car come with a wing?" "No" my Uncle replied, "She bought the car and the next day headed out to buy the wing!" My ninety something Nana had a car fitted with a wing spoiler. Seems her love for speed from her days travelling in a motorcycle sidecar hadn't left her.
When my mother wanted a new car, there was only one choice, since she was a massive fan of WRC and Petter Solberg. She got a brand new blob-eye STI in white. It’s still in glorious original condition and it’s her daily driver.
This was exactly at the right level for me. I've never followed classes in aerodynamics, but found the explanation with the CFD visualisations very understandable.
I remember in the early days of Formula D there was a yellow GTO that was a top runner. One of the odd things they did was put these clear plexiglass fins on the rear of the car between the C pillar and the wing. The reason they gave was for better control of the drift at high speed. Guessing it was a similar thing to the WRC cars. Was around the early 2000's and the driver I am pretty sure was a rally driver as well as Formula D. Drawing a blank on the name right now.
+KYLE.DRIVES - As an FYI, sometimes the fins on the rear wings are added as stabilizers to prevent the wing from breaking, too, given that there are some thin fibreglass spoilers fitted (i.e., to the 2004 STi) where the wing will flutter at high speeds...
Thanks for sharing! We were all having a recent conversation about this in a group about why folks went with skeletonized / cutout uprights vs solid, and what the benefits were etc etc. The most interesting response came from a fellow who did cutouts in the same shape as the aerofoil running fore to aft on the uprights. They found it reduced drag while also reducing weight.
Thank you for making all these videos! I'm a first year AE major who came in knowing absolutely nothing about cars OR very much about aerodynamics, but thanks to your channel and a few others I'm starting to pick up on everything.
Could you do a video on Autocross and Rallycross aerodynamics? Would be helpful to know how much their setups help at lower speeds than a typical circuit race.
Hey +KYLE.DRIVES, Two things: First, seeing you try and move the model around to show different phenomena on the CFD model reminded me of how much I love my SpaceMouse. idk how often you're in CFD and CAD, but I use it constantly. Its particulary useful when switching between programs that don't use the same 3D navigation commands (Ex. SolidWorks and ICEM CFD). It's also great when I try and show CFD results to someone as I can rotate around the same point without the model moving off screen. Anyways, didn't know if you've heard of it before, but I highly recommend it. Second, I asked a question on your strakes video, but didn't know if you check over old video comments or not. I'm just a bit confused on the nature of vortex "blocking" when it comes to diffuser flow. Could you check that out? thanks!
Waaaaay ahead of you =P th-cam.com/video/dQvCNEhuszw/w-d-xo.htmlm20s I just have it hooked up on my CAD workstation not my CFD workstation as I haven't gotten round to sorting the drivers out on the CFD computer/sorting Paraview settings. For most of my actual CFD work I'm not quite moving around as aggressively as this though! I'll go and take a quick look at your other question too. Thanks for watching!
Hey Kyle. I have a 2014 turbo BRZ and a 2017 STi, and I'm in several Subaru groups on Facebook, and I've seen a ton of people buying Perrin's "wing stabilizers"...though they're also known as "stiffies" to those groups. You can see them on Perrin's page by following this link: perrinperformance.com/i-23037505-wing-stabilizer-for-2015-17-sti-sedan.html Now, looking at their design, they're incredibly thin and don't have an aerofoil shape, so they really do seem to serve no aero purpose at all, unlike the real WRC wings that you've tried to explain here. These are the only sort of vertical fins I really see anymore, and it seems to just be a bunch of people wanting to look like rally drivers in their STis that will mostly never even see dirt. I've asked people for their reasoning behind buying them, and I'm not entirely opposed to the look, but I was curious if people thought they were getting them for the same reasons as rally drivers or not. A few said they noticed their wings vibrating at highway speeds, and I asked what their concern was about that, since it seems like a tiny bit of flex shouldn't affect the wing's ability to generate or transfer its downforce in any significant manner, but never got any answers. I'm curious to know if adding this for the looks (the reason that most people seem to do it) has any of the benefits or drawbacks of the fins in WRC wings with actual wing profiles. I couldn't tell how much of the drag or sideforce you showed was caused by the wing profile vs just disrupting the airflow in general, as these would still do even being so thin, especially when at a high yaw angle. Would it be possible to either give a quick answer here, or put up a brief follow-up video showing the CFD of this sort of design?
Hey +KYLE.DRIVES , just wanted to clarify.... finned rear wings increase side force when slip angle increases. Does this side force help bring the car back in line as quickly as possible or make the process of drifting more controllable??Btw, great video. Loved every minute of it
Here's a question. What if the shark fins sprouted from the bottom didn't reach all the way up the wing? Would you get vortexes that helped keep the flow attached on the underside?
What would you do for a 2000 Honda insight. To make it more aerodynamic in the boot area or the back of the car. Extend the back of the slope 3 feet more.?
Am I correct in thinking that rally cars have heavy bias towards rear downforce? I used to rally and ice race on an amateur level. I had a traditional wavy carbon fiber road race wing on my first car, which wasn’t as good as my second one with a wrc wing. It’s an old design without fins though. It still had more side force obviously. Thanks for the explanation. I can definitely see how it works now.
For those who are having a bit of trouble understanding. Wings don't like going at an angle. They lose downforce. Flow separates and shears off. The fins more or less redirect and force the air into the correct direction and they work better the sharper the yaw angle. The slight loss of downforce in the straight (or overall downforce) is a good trade off when you're keeping a lot of that down force while sliding through the dirt compared to normal road racing. This is one of the reasons why end plates are on wings compared to back in the 60's, because even if slightly, due to slip angle (your tires are literally bending and stretching to make it look like your car is drifting even if slightly) your wing will have some yaw and receive air perpendicular to where it's heading. so in reality. Road cars have to have the same thing as rally cars, but way less because they aren't expected to slip and slide.
I think you have the right idea, but one should take these CFD results with a massive grain of salt. I would want to see the mesh, know if you were using wall functions, know what solver and how the case was run (RANS surely not LES) ect
did that side force also take into account that drag? Because that extra drag in the rear would also help push that car back straight What programs did you use?
So on a 2015 WRX Sti with spoiler and vortex generator is that really doing anything for drag racing or track racing, or is it hurting the vehicle times period?
I couldn't message you, so, random question. I just bought a wrc spoiler for my 04 sti. Can I use the oem spoiler bolts for the wrc spoiler or will I need new ones?
Maybe, but there's nothing too special about it if I'm honest? I mean the concept has been done by other cars before, is there any particular reason you would like to see a video on it?
I'm not 100% sure, drifters are a higher level of yaw again which may cause weird blockage effects as the fins stall out. Also, you don't want to be yawing your drift car too hard back out of the drift or otherwise the driver will struggle to hold big angle, but you obviously want to maximise your rear end traction, so downforce is probably more useful. I have quite a few ideas for drift aero, just need to find a high level drift team that will take them on...
Thank you for the video, it is very clarifying. Just one question, why do you think current WRC have completely removed fins in their wings? Is that they are always short on downforce? By the way, I invite you to visit my website about current and historical evolution of rally cars rear wings at wrcwings.wordpress.com/
why do i keep getting recommended videos about aerodynamics? I ride a naked motorcycle because i literally do not give a shit so i am just saying, this is a bad match, I see this Kyle person as the bench racer that never rides or in this case drives a car but he does want me to respect his advice on the topic. Honestly i don't care, make videos about driving these high aero cars at their limit or i don't care but you obviously do have an audience for this stuff but damn...
Funny story, a few years ago my now deceased Nana came down to visit with her son and one granddaughter in her new to her Subaru. The plain one not the WRC or WRX, anyway I noticed the wing on the boot lid and commented; "Did the car come with a wing?" "No" my Uncle replied, "She bought the car and the next day headed out to buy the wing!" My ninety something Nana had a car fitted with a wing spoiler. Seems her love for speed from her days travelling in a motorcycle sidecar hadn't left her.
When my mother wanted a new car, there was only one choice, since she was a massive fan of WRC and Petter Solberg. She got a brand new blob-eye STI in white. It’s still in glorious original condition and it’s her daily driver.
@@ImInLoveWithBulla what id do to get an unmolested blobeye 🤤
This was exactly at the right level for me. I've never followed classes in aerodynamics, but found the explanation with the CFD visualisations very understandable.
I remember in the early days of Formula D there was a yellow GTO that was a top runner. One of the odd things they did was put these clear plexiglass fins on the rear of the car between the C pillar and the wing. The reason they gave was for better control of the drift at high speed. Guessing it was a similar thing to the WRC cars. Was around the early 2000's and the driver I am pretty sure was a rally driver as well as Formula D. Drawing a blank on the name right now.
+KYLE.DRIVES - As an FYI, sometimes the fins on the rear wings are added as stabilizers to prevent the wing from breaking, too, given that there are some thin fibreglass spoilers fitted (i.e., to the 2004 STi) where the wing will flutter at high speeds...
What I learned here today is that I need to make a rally van.
If you got the money, I have the van.
Hatch backs.
ßIGpoppaKEGdog™ ii
Just buy a WRC Toyota yaris its pretty much the same.
"hope i didnt get to engineery on that" - thats what we´re here for!
Thanks for sharing! We were all having a recent conversation about this in a group about why folks went with skeletonized / cutout uprights vs solid, and what the benefits were etc etc.
The most interesting response came from a fellow who did cutouts in the same shape as the aerofoil running fore to aft on the uprights. They found it reduced drag while also reducing weight.
Thank you for making all these videos! I'm a first year AE major who came in knowing absolutely nothing about cars OR very much about aerodynamics, but thanks to your channel and a few others I'm starting to pick up on everything.
Could you do a video on Autocross and Rallycross aerodynamics? Would be helpful to know how much their setups help at lower speeds than a typical circuit race.
Just found your channel. Awesome videos, with no bullshit. Now, I've got to work through all of your previous videos and learn me some stuff.
I loved your use of CFD here, really helps convey the point across. I would like to see more of these videos
Cheers Mark, there's another one coming out in a few weeks!
+Kyle what CFD package is that? I've only ever used STAR CCM+ and codes written by ourselves.
Excellent job. I really enjoy your videos. I finished Vehicle Aerodynamics course last semester but taking Advanced aero here soon !!
Really good info. It is refreshing to watch someone who knows his stuff so well.
aero engineer doesnt know if its a fiesta or a focus = my world crumbles XD
very informative, keep it up!
Thanks for the compliments!
Hey +KYLE.DRIVES, Two things: First, seeing you try and move the model around to show different phenomena on the CFD model reminded me of how much I love my SpaceMouse. idk how often you're in CFD and CAD, but I use it constantly. Its particulary useful when switching between programs that don't use the same 3D navigation commands (Ex. SolidWorks and ICEM CFD). It's also great when I try and show CFD results to someone as I can rotate around the same point without the model moving off screen. Anyways, didn't know if you've heard of it before, but I highly recommend it.
Second, I asked a question on your strakes video, but didn't know if you check over old video comments or not. I'm just a bit confused on the nature of vortex "blocking" when it comes to diffuser flow. Could you check that out? thanks!
Waaaaay ahead of you =P th-cam.com/video/dQvCNEhuszw/w-d-xo.htmlm20s
I just have it hooked up on my CAD workstation not my CFD workstation as I haven't gotten round to sorting the drivers out on the CFD computer/sorting Paraview settings. For most of my actual CFD work I'm not quite moving around as aggressively as this though!
I'll go and take a quick look at your other question too. Thanks for watching!
Haha, great minds think alike?
Hey Kyle. I have a 2014 turbo BRZ and a 2017 STi, and I'm in several Subaru groups on Facebook, and I've seen a ton of people buying Perrin's "wing stabilizers"...though they're also known as "stiffies" to those groups. You can see them on Perrin's page by following this link: perrinperformance.com/i-23037505-wing-stabilizer-for-2015-17-sti-sedan.html
Now, looking at their design, they're incredibly thin and don't have an aerofoil shape, so they really do seem to serve no aero purpose at all, unlike the real WRC wings that you've tried to explain here. These are the only sort of vertical fins I really see anymore, and it seems to just be a bunch of people wanting to look like rally drivers in their STis that will mostly never even see dirt. I've asked people for their reasoning behind buying them, and I'm not entirely opposed to the look, but I was curious if people thought they were getting them for the same reasons as rally drivers or not. A few said they noticed their wings vibrating at highway speeds, and I asked what their concern was about that, since it seems like a tiny bit of flex shouldn't affect the wing's ability to generate or transfer its downforce in any significant manner, but never got any answers.
I'm curious to know if adding this for the looks (the reason that most people seem to do it) has any of the benefits or drawbacks of the fins in WRC wings with actual wing profiles. I couldn't tell how much of the drag or sideforce you showed was caused by the wing profile vs just disrupting the airflow in general, as these would still do even being so thin, especially when at a high yaw angle. Would it be possible to either give a quick answer here, or put up a brief follow-up video showing the CFD of this sort of design?
Hey +KYLE.DRIVES , just wanted to clarify.... finned rear wings increase side force when slip angle increases. Does this side force help bring the car back in line as quickly as possible or make the process of drifting more controllable??Btw, great video. Loved every minute of it
digging up old videos, but curious the thoughts on the finned wing at LeMans on the Glickenhaus car?
Here's a question. What if the shark fins sprouted from the bottom didn't reach all the way up the wing? Would you get vortexes that helped keep the flow attached on the underside?
Can u make a video analyzing new 2017 spec rally cars?
0ExG0 yeah I've always wondered how the curved edges of the wings work like on the fiesta wrc. Also all of the ducts they run around the wheel wells.
so this video was in my recommended.. i can tell im going to like this channel
What would you do for a 2000 Honda insight. To make it more aerodynamic in the boot area or the back of the car. Extend the back of the slope 3 feet more.?
dude my dad has that exact mousepad. its probably 20 years old.
mushieslushie dude I have the same one this is insane. Marvin the Martian taking over W T F
Am I correct in thinking that rally cars have heavy bias towards rear downforce? I used to rally and ice race on an amateur level. I had a traditional wavy carbon fiber road race wing on my first car, which wasn’t as good as my second one with a wrc wing. It’s an old design without fins though. It still had more side force obviously. Thanks for the explanation. I can definitely see how it works now.
does this phenomen have the same effect on a difusor with very long fins?
If they stick out from the car (A few centimeters out), yeah, that might work like spoiler in this vid.
Would huge endplates give the best of both worlds? What about those full length raised drip rail like things on the tops of NASCARs?
For those who are having a bit of trouble understanding.
Wings don't like going at an angle. They lose downforce. Flow separates and shears off. The fins more or less redirect and force the air into the correct direction and they work better the sharper the yaw angle. The slight loss of downforce in the straight (or overall downforce) is a good trade off when you're keeping a lot of that down force while sliding through the dirt compared to normal road racing. This is one of the reasons why end plates are on wings compared to back in the 60's, because even if slightly, due to slip angle (your tires are literally bending and stretching to make it look like your car is drifting even if slightly) your wing will have some yaw and receive air perpendicular to where it's heading.
so in reality. Road cars have to have the same thing as rally cars, but way less because they aren't expected to slip and slide.
I would like to see a video on Top fuel funny cars and incorporate header angles and center of pressure on the body.
Congrats. Very good. You woul make a video equal to this one with the difference between swan wing and normal wing.
I think you have the right idea, but one should take these CFD results with a massive grain of salt. I would want to see the mesh, know if you were using wall functions, know what solver and how the case was run (RANS surely not LES) ect
did that side force also take into account that drag? Because that extra drag in the rear would also help push that car back straight
What programs did you use?
Is it possible to have a friction coeficient bigger than 1?
how much does a twisted wing provide this effect? is it more optimal for the weight?
Isn't drag also a benefit it keeps your center of pressure forward like fins in an arrow or a rocket right?
N-No?
So on a 2015 WRX Sti with spoiler and vortex generator is that really doing anything for drag racing or track racing, or is it hurting the vehicle times period?
Gerry Rodriguez hurting drag racing, helps road racing
I couldn't message you, so, random question. I just bought a wrc spoiler for my 04 sti. Can I use the oem spoiler bolts for the wrc spoiler or will I need new ones?
Can somebody please fix the camera navigation of the CFD software? This is painful to watch!
Does it matter if it is a round earth or flat one?... do these wings work the same?
+KYLE.DRIVES Hey kyle, would you be able to make a video on ariel's new fan car?
Maybe, but there's nothing too special about it if I'm honest? I mean the concept has been done by other cars before, is there any particular reason you would like to see a video on it?
Maybe just cover the concept in general, upsides, downsides, that sort of deal. We do always love the oddball inventions.
what is the programm?
The visualization is done in paraview. Not sure what he used for the simulation.
Maybe they wanted have more robustness on the wing ? 🤔
Sounds like Wing Fins are good for drift cars as well.
I'm not 100% sure, drifters are a higher level of yaw again which may cause weird blockage effects as the fins stall out. Also, you don't want to be yawing your drift car too hard back out of the drift or otherwise the driver will struggle to hold big angle, but you obviously want to maximise your rear end traction, so downforce is probably more useful. I have quite a few ideas for drift aero, just need to find a high level drift team that will take them on...
Ahh, thanks for answering. I'm no drifter by any means, but I was just wondering. :)
Thank you for the video, it is very clarifying. Just one question, why do you think current WRC have completely removed fins in their wings? Is that they are always short on downforce?
By the way, I invite you to visit my website about current and historical evolution of rally cars rear wings at wrcwings.wordpress.com/
It's for styling so you'll go and buy one of these it's total rice most people just drive on the street with these cars
Geez. Very hard to watch as you move the picture constantly.
Jesus. Your mouse skills made me dizzy. Great explanation though.
Nice video, but please stop moving the model around every second..
Wrc... wing explained : don't do it...
Peel off the damn stickers.
why do i keep getting recommended videos about aerodynamics?
I ride a naked motorcycle because i literally do not give a shit so i am just saying, this is a bad match,
I see this Kyle person as the bench racer that never rides or in this case drives a car but he does want me to respect his advice on the topic.
Honestly i don't care, make videos about driving these high aero cars at their limit or i don't care but you obviously do have an audience for this stuff but damn...