In NASCAR, Fireball Roberts iirc ran a flat floor for a while and really increased his performance. Forgot why he stopped, might have been tech finally started looking under there.
I can not thank you enough for all your videos Kyle, you've changed my way of thinking with an aero package I want to do on my Skyline. Hopefully in the near future I'll be in contact with you with the ideas I have and we can fine tune them. Keep up the fantastic work. Can't wait for part 2 :)
Can you do a video on the Ariel Atom with the ground effects, analyzing how much downforce it might actually make and how efficient it would be? Thanks.
KYLE.ENGINEERS Do it, because everyone knows that a youtuber’s sole purpose is to ignore all his own desires and dedicate countless hours and suffering for the fulfillment of a ten second whim of a subscriber. Jk I would like to se that too, and it would be interesting to see whether or not an aerodynamic skin could increase performance to offset its extra weight. Sorry for the long comment, anything to avoid finals study.
I put my first floor pan on my race only Triumph 'Spitfire' back in the late 60's looking for a little extra speed on the long straights. Like my Miata, the Spit was a momentum car and in a stock class so no engine improvements could be done. I went through quite a few tech checks before anyone noticed, but they took no action. i did see a couple(2-3) of MPH on longer straights Later I added a short(3") skirt at the sides of the pan and I noted reaching about one MPH higher, but I reached that speed earlier and on shorter straights. No way to actually get an accurate number as there are too many inherent variables form day to day and through the day. I did end up cutting down the side skirts to (2-1/2") due to clearance issues, but it didn't seem to change behavior. Thanks for the post.
all the nitpicky comments on the last video lol calm tf down were building a race car to have fun. people always wanna talk crap. we went to school to know how to do things the right way. we're not gonna calculate every dang thing on on a video lol u want that? buy some books, and programs. your lucky enough this guy likes this stuff enough to make videos, and offer services to help you do it right.
Thanks for the compliments! I've done the testing on that one, but there are some things I still like to keep as personal knowledge rather than just give out to the public, gotta make a living somehow!
I was thinking about putting a flat floor on the front of a squarebody truck and making side vents on the fenders or out the hood to move the air and heat from the front of the truck smoothly
I thought this one was going to talk about F1, still really interesting analysis and visualization! I would like to know your take on allowing greater ground effect on F1 for solving the dirty air problem which prevents cars from staying close behind one another in corners. It's something that has been mentioned often in some circles and seems plausible.
Interesting, I would of love it if you showed a Porsche 911 997 that has a full flat floor vs a 991 911 with a semi flat floor .... now that would make for a wonderful video for the track use...... thanks I'm impressed
Great stuff! Really like your videos! Can't believe your videos aren't watched by more people... I'm really interested in how much side skirts come in to play with these examples, planning on doing a video on that?
So why don't we all do this to our daily drivers/ family cars? Seems a simple thing for a major manufacturer to do. I'm sure my 2006 Camry would love less drag and some downforce!
enoying all your vids. i saw a video today of a crash of the 1992 imsa nissan GTP where it flipped and you can see the flat floor and huge tunnels and diffuser with strakes of different lengths
You mention R35 GT-Rs often in your videos, which is awesome. As an owner of one, I have noticed that it only has a flat floor at the front 1/3 and back 1/3, but not in the middle portion. Do you think you could improve ground effect and rear diffuser by adding a panel to cover the middle portion?
Build one and do a coast down test with it and with out it. This would measure drag reduction. Then you could track ride height with potentiometers on your suspension or with camera on your suspension to measure how much the springs compress at a fixed mph for with the the added floor piece and without the added floor piece. This would tell you gains in down force.
That's Ground Effect, its awesome and should never had been banned, if something is revolutionary FIA bans it... The cars became too fast, the problem is that tracks had oscillations on the surface, it made downforce oscillate and hard for the driver to predict car handling, that's why they blamed ground effect from F1...
That's pretty cool to see it like that. My immediate thought, was "how does this affect cooling airflow?". As in, are the other exits from the engine bay generally good enough to cover for there not being a massive hole? Is it *improved*?
Kyle, would the flat floor or underbelly pan make a significant difference on fuel economy between 45 to 80 mph ? Do you have a video using these principles for hypermiling/ecomodding?
Was wondering about that as well.. on a stock height car or even a truck? Feel like efficiency gains on the truck could be massive even though it would be a bit silly
Flat floors are inherently better at aerodynamic efficiency because they significantly lower the underside air pressure which results in better aerodynamic stability
my question is: by adding a flat floor like that on a 60 hp/700 kg trackcar. If its original topspeed is 163, how much would it be aftef adding that upgrade? Thank you very much! And btw, I really like your content 👌 keep it up
Great video buddy! I was planning to put a undertray or a flat floor for the car but some people have mixed opinions about it! Like they say it heats up the engine bay because the air doesn't escape and the temperature rises! Could you give me your advice! Thanks and waiting for your response sir!
what material would you recommend that would be suitable for an undertray to wont bow but is still raltively lightweight? In regards to retrofitting an undertray on a production sports car....
Probably not your thing, but I need a Suv with a flat floor as you enter and exit the vehicle. As I began shopping, all the models had a floor well. I get it, it's for more leg room. My situation is that my right leg has a orthopedic device and is very difficult to pick up and the exit. It hangs up on the ridge created by the floor well. Any suggestions of models with flat floor or a method to make the existing floor well even with the car threshold ? I hope I've explained my problem.........
What would happen if u were to put a rubber skirt in the front and sides and left the back open? Would that reduce air flow beneath the car to a point to create a vacuum and therefore that low pressure would cause a greater downforce?
What do you think of something like this on a large car like a 2008-2015 Nissan Armada? Its very tall, for example, I have no (steps) on the sides i removed them and was wondering about making a flat bottom for highway driving. Would any kind of feature at the front, due to its height help the aerodynamics? Like a wing that maybe pushes air, not sure. Currently I just have the wing on the front of the hood which comes standard. I just feel like the car has TONS of space below it and it would be incredibly easy to just seal off most of the bottom.
Hi, I know this is an old video but hopefully someone can answer my question. What's the reason for not running the undertray lower than the exhaust so its flat all the way along? Or is that a viable solution? If so, would it cause any unwanted effects to do with temperatures of the exhaust pipe/underside of the car or can we get away with it? If the exhaust hangs too low how would creating a separate flat section that hangs lower to cover the exhaust pipe affect the airflow? Thanks
If you go slower than 180km/h. Do you still get any benefits of flat floor ? Or at witch speed did you say at 1:49 ? Like would you benefit if you go over 100 km/h ?
Especially without front splitter! More air in a narrow (smooth) space = higher velocity. High velocity = low pressure. Low pressure under the car = downforce. Front splitters were functional before good undertrays were developed. Don't forget to provide a substantial 8 to 10% diffuser. This way you'll create more downforce plús lower drag, win-win...
CONGRATULATIONS for your videos!! I am following them. I would wish to do a suggestion: speak less quicky!! slower and clairly will be better for understanding of all us (foreigners) .. and so .. the international audience will be bigger. Sorry and Thank you very much. Go !!!!
KYLE.DRIVES. My bad, I mean like the small wings on the front number. Like how gt3 cars have. Or the ACR viper. I've always been curious if they really add any downforce
Those actually increase drag. On a perfectly smooth golf ball there is one very large reciprocating vortex, this makes the ball curve. When the dimples are added it creates many small vortexes around the ball making it fly straight.
I guess I feel like if you want to learn about this stuff you should start learning the difference between force and mass. Besides, the forces are compared to each other so you don't need to know the exact units to get a rough idea of the effect.
STOP CONSTANTLY MOVING THE MODEL WHEN YOU'RE IN MESH MODE FFS! just put it on a good position, zoom a little bit out and explain it from there without bulking it up each time by moving it! You almost lost 1 like there...
Can you do a video on putting aerodynamic covers over your rear wheels and/or all wheels?
Depends on the car body style and how flush the stock wheels are. I had an 8% fuel economy improvement at best. After traffic, etc it was under 5%
In NASCAR, Fireball Roberts iirc ran a flat floor for a while and really increased his performance. Forgot why he stopped, might have been tech finally started looking under there.
Great video. I’m considering building a flat floor for my momentum car to reduce all possible drag. So I can get those last few mph on the straights
Doing the same for my Vic definitely needs it 😂
I can not thank you enough for all your videos Kyle, you've changed my way of thinking with an aero package I want to do on my Skyline. Hopefully in the near future I'll be in contact with you with the ideas I have and we can fine tune them. Keep up the fantastic work. Can't wait for part 2 :)
Can you do a video on the Ariel Atom with the ground effects, analyzing how much downforce it might actually make and how efficient it would be? Thanks.
Maybe, that one is going to be very difficult to CFD though!
KYLE.ENGINEERS Do it, because everyone knows that a youtuber’s sole purpose is to ignore all his own desires and dedicate countless hours and suffering for the fulfillment of a ten second whim of a subscriber. Jk I would like to se that too, and it would be interesting to see whether or not an aerodynamic skin could increase performance to offset its extra weight. Sorry for the long comment, anything to avoid finals study.
Great you addressed the questions asked on the diffuser vs. no bumper video.
I put my first floor pan on my race only Triumph 'Spitfire' back in the late 60's looking for a little extra speed on the long straights. Like my Miata, the Spit was a momentum car and in a stock class so no engine improvements could be done. I went through quite a few tech checks before anyone noticed, but they took no action. i did see a couple(2-3) of MPH on longer straights Later I added a short(3") skirt at the sides of the pan and I noted reaching about one MPH higher, but I reached that speed earlier and on shorter straights. No way to actually get an accurate number as there are too many inherent variables form day to day and through the day. I did end up cutting down the side skirts to (2-1/2") due to clearance issues, but it didn't seem to change behavior. Thanks for the post.
all the nitpicky comments on the last video lol calm tf down were building a race car to have fun. people always wanna talk crap. we went to school to know how to do things the right way. we're not gonna calculate every dang thing on on a video lol u want that? buy some books, and programs. your lucky enough this guy likes this stuff enough to make videos, and offer services to help you do it right.
Moving the Mufflers forward seem to be Ideal as it's not causing as much wake(Dirty air) at the sensitive diffuser.
Great vid, as always. Could you make a video about frontsplitters and why they are sometimes tilted up or down?
Thanks for the compliments! I've done the testing on that one, but there are some things I still like to keep as personal knowledge rather than just give out to the public, gotta make a living somehow!
I want a flat under tray on my truck and i very it would have a MASSIVE improvement on drag.
Hi
It possible for you to comment on the ride height influence compared to gains in downforce ?
Martin Knudsen the lower the front of the car, in most cases, will increase downforce. So in general, a lower ride height does increase downforce
Less in drag, increase in flow & a little increase in downforce. Just look at land speed cars short & narrow
I was thinking about putting a flat floor on the front of a squarebody truck and making side vents on the fenders or out the hood to move the air and heat from the front of the truck smoothly
I thought this one was going to talk about F1, still really interesting analysis and visualization!
I would like to know your take on allowing greater ground effect on F1 for solving the dirty air problem which prevents cars from staying close behind one another in corners. It's something that has been mentioned often in some circles and seems plausible.
I've got a video in the works on that one, just have to get around to finishing it sometime...
Glad you liked the video!
Love to do a flat floor on my mk1 escort!
Interesting, I would of love it if you showed a Porsche 911 997 that has a full flat floor vs a 991 911 with a semi flat floor .... now that would make for a wonderful video for the track use...... thanks I'm impressed
Damn this was a great video, i love those 3D models you made also.
Great stuff! Really like your videos!
Can't believe your videos aren't watched by more people...
I'm really interested in how much side skirts come in to play with these examples, planning on doing a video on that?
So why don't we all do this to our daily drivers/ family cars? Seems a simple thing for a major manufacturer to do. I'm sure my 2006 Camry would love less drag and some downforce!
Today's models do! check out the floor of any new hybrid!
Great video Kyle. Thank you for addressing this
enoying all your vids. i saw a video today of a crash of the 1992 imsa nissan GTP where it flipped and you can see the flat floor and huge tunnels and diffuser with strakes of different lengths
Good stuff!
Thanks for the compliments!
What free softwares do you recommend to test the dynamics of a vehicle? Thanks!
You mention R35 GT-Rs often in your videos, which is awesome. As an owner of one, I have noticed that it only has a flat floor at the front 1/3 and back 1/3, but not in the middle portion. Do you think you could improve ground effect and rear diffuser by adding a panel to cover the middle portion?
Build one and do a coast down test with it and with out it. This would measure drag reduction. Then you could track ride height with potentiometers on your suspension or with camera on your suspension to measure how much the springs compress at a fixed mph for with the the added floor piece and without the added floor piece. This would tell you gains in down force.
What about inverse wing floor like the one that got banned in F1 lotus car with sliding side skirts.
That's Ground Effect, its awesome and should never had been banned, if something is revolutionary FIA bans it...
The cars became too fast, the problem is that tracks had oscillations on the surface, it made downforce oscillate and hard for the driver to predict car handling, that's why they blamed ground effect from F1...
Hi quick question. For a autocross/hill climb car, would a flat floor be significant enough on its own, even without a diffuser?
Ah this guy needs more views
Awesome Kyle! This is a great and very educational series.
Thanks for the compliments! Glad you're finding it useful!
Very much so! Your last videos provoked a couple cut bumpers and one guy building a fin... for a Miata that is.
Shark fin Miata? Love it! Send through some pics to kyle@jkfaero.com when it's done!
That's pretty cool to see it like that. My immediate thought, was "how does this affect cooling airflow?". As in, are the other exits from the engine bay generally good enough to cover for there not being a massive hole? Is it *improved*?
Yes it is improved, and engine bay temperatures drop quite a bit, helping cool intake and intake pipes and other sensors on engine for example.
My exhaust is tucked in the frame. My long tube headers might be the biggest problem
I’m here trying to figure out if I can improve mpg with under body aerodynamics
Kyle, would the flat floor or underbelly pan make a significant difference on fuel economy between 45 to 80 mph ? Do you have a video using these principles for hypermiling/ecomodding?
Was wondering about that as well.. on a stock height car or even a truck? Feel like efficiency gains on the truck could be massive even though it would be a bit silly
@@buildingsalvage ...I'm considering it for a '71 ElCo, which I hope to take on road trips
Flat floors are inherently better at aerodynamic efficiency because they significantly lower the underside air pressure which results in better aerodynamic stability
Good job!!!! Keep up the great work!!!
my question is: by adding a flat floor like that on a 60 hp/700 kg trackcar. If its original topspeed is 163, how much would it be aftef adding that upgrade? Thank you very much! And btw, I really like your content 👌 keep it up
Great video buddy! I was planning to put a undertray or a flat floor for the car but some people have mixed opinions about it! Like they say it heats up the engine bay because the air doesn't escape and the temperature rises! Could you give me your advice! Thanks and waiting for your response sir!
what material would you recommend that would be suitable for an undertray to wont bow but is still raltively lightweight? In regards to retrofitting an undertray on a production sports car....
Aluminum sheets ?
How many drag points can you lose with a flat floor?
Can you make a video about reducing drag for electrical conversions?
Awesome video, good job
Modern cars have funny diffuser looking objects on the rear, are those effective? Thanks
Probably not your thing, but I need a Suv with a flat floor as you enter and exit the vehicle. As I began shopping, all the models had a floor well. I get it, it's for more leg room. My situation is that my right leg has a orthopedic device and is very difficult to pick up and the exit. It hangs up on the ridge created by the floor well. Any suggestions of models with flat floor or a method to make the existing floor well even with the car threshold ? I hope I've explained my problem.........
What program do you use to simulate air flow? Thank you and great video.
if you're placing a floor below your engine bay. Does that mean you need hood vents? Else, where will the air go?
Hi Kyle. Which CFD/mesh package are you using? Thanks for the videos.
What would happen if u were to put a rubber skirt in the front and sides and left the back open? Would that reduce air flow beneath the car to a point to create a vacuum and therefore that low pressure would cause a greater downforce?
Can you do a CFD and video on the Lotus Exige? Maybe what you would add/change to make it better? :P
How significant is the drag of offset wheels vs aerodynamic "clean" wheels vs propeller like rims?
So a flat floor shouldn't cover the exhaust piping? Guess that makes sense, otherwise the heat would just build up like crazy
What do you think of something like this on a large car like a 2008-2015 Nissan Armada? Its very tall, for example, I have no (steps) on the sides i removed them and was wondering about making a flat bottom for highway driving. Would any kind of feature at the front, due to its height help the aerodynamics? Like a wing that maybe pushes air, not sure.
Currently I just have the wing on the front of the hood which comes standard.
I just feel like the car has TONS of space below it and it would be incredibly easy to just seal off most of the bottom.
a video about everyday mods for normal people and aprox. how much those actually bring
Hi, I know this is an old video but hopefully someone can answer my question. What's the reason for not running the undertray lower than the exhaust so its flat all the way along? Or is that a viable solution? If so, would it cause any unwanted effects to do with temperatures of the exhaust pipe/underside of the car or can we get away with it? If the exhaust hangs too low how would creating a separate flat section that hangs lower to cover the exhaust pipe affect the airflow? Thanks
Where does the airflow from the engine bay go when you close off for a smooth bottom?
Trix Kemuel Up
Up
It goes straight into your brain
Could you do one of these videos on the AM-RB 001? I saw the video on it, but I'd also like to see air flow simulations on it.
Well, if you can get me some CAD geometry of it...
If you go slower than 180km/h. Do you still get any benefits of flat floor ? Or at witch speed did you say at 1:49 ? Like would you benefit if you go over 100 km/h ?
So a flat floor will provide extra downforce even without a proper splitter out front?
Especially without front splitter! More air in a narrow (smooth) space = higher velocity.
High velocity = low pressure. Low pressure under the car = downforce.
Front splitters were functional before good undertrays were developed.
Don't forget to provide a substantial 8 to 10% diffuser.
This way you'll create more downforce plús lower drag, win-win...
How much fuel efficency is there on highway speed at 150kmh with a fal flor?
15Kg of drag at 180km/h really doesn't sound like that much. What's the difference in percentage?
CONGRATULATIONS for your videos!! I am following them. I would wish to do a suggestion: speak less quicky!! slower and clairly will be better for understanding of all us (foreigners) .. and so .. the international audience will be bigger. Sorry and Thank you very much. Go !!!!
Did you include exhaust gas temperature or just flow simulation?
Please produce more videos
What about gurney flaps on the front bumper ?
Haha It's hard enough finding the time to do one a week, don't get your hopes up...
Not sure which gurneys you're referring to?
KYLE.DRIVES. My bad, I mean like the small wings on the front number. Like how gt3 cars have. Or the ACR viper. I've always been curious if they really add any downforce
What software do you use for diffuser type of aerodynamic part's cfd?
Well done again sir.
I'm curious of the effect of dimpled (golfball like) surfaces, I.e. underbody, and the rest of the car, could this be a thing of the future?
Those actually increase drag. On a perfectly smooth golf ball there is one very large reciprocating vortex, this makes the ball curve. When the dimples are added it creates many small vortexes around the ball making it fly straight.
good video, what software are you using ?
What CFD program do you use?
ParaView
What FEA/CFD software is that?
You need a bigger monitor mate. Shoot for 27", still looks fine with just HD resolution.
I really appreciate your content, but it kills me when you give forces in grams and kilograms
I guess I feel like if you want to learn about this stuff you should start learning the difference between force and mass. Besides, the forces are compared to each other so you don't need to know the exact units to get a rough idea of the effect.
Bug-Shield and Car-Bra Aerodynamic Please.
Your eyes have the uni look to them in this video.
Flat four is a engine
lets talk about bongs
Why are you using kg instead of Newtons. That's not correct.
STOP CONSTANTLY MOVING THE MODEL WHEN YOU'RE IN MESH MODE FFS! just put it on a good position, zoom a little bit out and explain it from there without bulking it up each time by moving it! You almost lost 1 like there...
You have a pause button, and options to slow the video down in settings.
Hi. buy sesame oil, beacuse you look pale. Much health.