Tesla Model 3 Rear Wing?

[Eno Deb]

Unless I'm totally misunderstanding this video, MIT would disagree with you.

Not really. I only skipped through the video, but what he's saying is that an airfoil can create downforce with less drag than a spoiler. It still creates more drag than using neither a spoiler nor an airfoil.

BTW, if you ignore downforce (which doesn't really make any sense for street cars) a well-designed lip spoiler on a not-so-well designed car can actually improve aerodynamics (if it results in cleaner air separation). But I doubt that this is the case for the Model 3. This is one of the most aerodynamic cars around, and there is a lot more opportunity to screw it up than to improve it.

 

[Roentgen]

Not really. I only skipped through the video, but what he's saying is that an airfoil can create downforce with less drag than a spoiler. It still creates more drag than using neither a spoiler nor an airfoil.

BTW, if you ignore downforce (which doesn't really make any sense for street cars) a well-designed lip spoiler on a not-so-well designed car can actually improve aerodynamics (if it results in cleaner air separation). But I doubt that this is the case for the Model 3. This is one of the most aerodynamic cars around, and there is a lot more opportunity to screw it up than to improve it.

You're not wrong, but not entirely correct (again, assuming I'm not misunderstanding the video, which is a big assumption!). And I agree, this would also be very dependent on how a spoiler or airfoil could change the presumably superior aerodynamcs of the 3.

This was a big deal when they first announced the spoiler for the model X, and Elon claimed that it would improve aerodynamics and range vs without the spoiler. Someone here posted the video, which is why I had the impression that a spoiler/airfoil could improve aerodynamics and therefore range also on the 3.

Basically, that a properly designed spoiler/airfoil will increase turbulence behind the car, but in strategic places which ultimately improve total laminar air flow around the car decreasing overall drag. If you get a chance, please watch the video in its entirety and let me know if I'm wrong here.

 

[Thomas Edison]

View attachment 351931

What format is that file in and where did you get the model from?

 

[CruzinTX]

You're not wrong, but not entirely correct (again, assuming I'm not misunderstanding the video, which is a big assumption!). And I agree, this would also be very dependent on how a spoiler or airfoil could change the presumably superior aerodynamcs of the 3.

This was a big deal when they first announced the spoiler for the model X, and Elon claimed that it would improve aerodynamics and range vs without the spoiler. Someone here posted the video, which is why I had the impression that a spoiler/airfoil could improve aerodynamics and therefore range also on the 3.

Basically, that a properly designed spoiler/airfoil will increase turbulence behind the car, but in strategic places which ultimately improve total laminar air flow around the car decreasing overall drag. If you get a chance, please watch the video in its entirety and let me know if I'm wrong here.

I understood it the same as you. Strategically weighing the benefits of lift and drag can result in increased efficiency in aerodynamics. Couple that with a lip spoiler and you can improve the Model3 performance on the track.

 

[CruzinTX]

The wing is the first part of a design exercise to transform the look of the 3. It will have a speed sensitive lowering mechanism powered by dual motors in the rear trunk. Designed to increase downforce to the rear wheels for launch and cornering and can be lowered to minimize the effects on range and top speed.
This is to be followed by a new front face to balance the new rear down force, wider fenders to accommodate wider tires, side skirt, and a new rear diffuser.
I got a little excited at how the wing turned out and decided to share before the design is completed. A little bit out of context here, but I thought the design could stand on its own merit.
Thanks for all the inputs.
CJ

I see where you're coming from now CJ. The airfoil sounds like an adjustable one ideally for track purpose. TBH, if you are doing that, maybe a slightly bigger one would be better. You know what they say, go big or go home =p Hehe

 

[AustinPowers]

Wings? Honestly? How Eighties/Nineties is that?
Why not fake quadruple exhaust pipes as well? And of course a "Kenwood" sticker all across the rear window.

Imho wings on anything but a true track racecar are just as smeggin' stupid as the "The Fast and the Furious" movies...

 

[Roentgen]

Wings? Honestly? How Eighties/Nineties is that?
Why not fake quadruple exhaust pipes as well? And of course a "Kenwood" sticker all across the rear window.

Imho wings on anything but a true track racecar are just as smeggin' stupid as the "The Fast and the Furious" movies...

Despite not being a fan of the look myself, if science tells me that this will help me get better performance, range, and efficiency from my car, I'd consider it. At the right price.

 

[AustinPowers]

Despite not being a fan of the look myself, if science tells me that this will help me get better performance, range, and efficiency from my car, I'd consider it. At the right price.

According to which physical laws should something that is there to add downforce help you get better range and/or efficiency? Performance, as in handling? Quite likely, depending on how it is implemented. But anything in the effciency/range department should only benefit from making the car more slippery and less road and wind resistant, should it not?

 

[Roentgen]

@AustinPowers
If you have time, please watch the video in post #19 I linked above, and tell me if I’m wrong in thinking that this could improve range in addition to handling. Again, this controversy played itself out also when the spoiler for the X was announced, and Elon said it would improve range.

 

[The Only Marc]

That's a nice looking wing Chojn1. What material would it be made from?

 

[chojn1]

That's a nice looking wing Chojn1. What material would it be made from?

Carbon fiber over a PETG core.

 

[Eno Deb]

Basically, that a properly designed spoiler/airfoil will increase turbulence behind the car, but in strategic places which ultimately improve total laminar air flow around the car decreasing overall drag. If you get a chance, please watch the video in its entirety and let me know if I'm wrong here.

Watched the whole thing now, and at no point does he say or explain how an airfoil could reduce drag compared to having no airfoil and no spoiler. If, as you say, the airfoil increases turbulence (which seems intuitively true since you now have air separating from two surfaces instead of one), that obviously means it will increase drag.

Again, I highly doubt that it's that easy to improve on Tesla's airflow optimizations which resulted in a best-of-class drag coefficient. If you want to do this for the optics, that's perfectly fine, but don't expect a positive impact on range and efficiency.

 

[Roentgen]

Watched the whole thing now, and at no point does he say or explain how an airfoil could reduce drag compared to having no airfoil and no spoiler. If, as you say, the airfoil increases turbulence (which seems intuitively true since you now have air separating from two surfaces instead of one), that obviously means it will increase drag.

Again, I highly doubt that it's that easy to improve on Tesla's airflow optimizations which resulted in a best-of-class drag coefficient. If you want to do this for the optics, that's perfectly fine, but don't expect a positive impact on range and efficiency.

From the video, I inferred that for the same car, spoiler/wing vs no spoiler/wing, a car would have improved performance over otherwise same parameters. If that doesn't imply improved range or efficiency, I'm not sure what else could except the raw numbers.

Cant find the quote from Elon that I was expecting to regarding the Model X spoiler, but here's a reddit thread quoting a thread from this forum, also quoting an article from Car and Driver on a 2010 panamera about how their spoiler deploys at highway speeds to improve drag.

I wish I was more of an engineer so I could offer an intelligent discussion with you about how and why. The only authority I can claim is that I have an early Model X and got the active spoiler for free, so had read that it offers improved efficiency at highway speeds (by tilting down vs the now typical fixed X spoiler). <shrug.> That's why I have to depend on sources (i.e MIT and Porsche product claims, which seem pretty reliable) as to the validity.

EDIT:
A little more searching found mention of the Kamm Effect, I presume explains how spoilers can help reduce overall drag.

 

[Roentgen]

Kamm effect or Kammback from Wunibald Kamm wiki:

Aerodynamic theory[edit]
The ideal shape to minimize drag is a teardrop. However researchers including Kamm found that abruptly cutting off the tail resulted in minimal increase in drag.[3] The reason for this is that a turbulent wake region forms behind the vertical surface at the rear of the car. This wake region mimics the effect of the tapered tail in that air in the free stream does not enter this region (avoiding boundary layer separation), therefore smooth airflow is maintained which minimises drag.[9]

Kamm's design is based on the tail being truncated at the point where the cross section area is 50% of the car's maximum cross section,[3][11] which Kamm found represented a good compromise—by that point the turbulence typical of flat-back vehicles had been mostly eliminated at typical speeds.

@Eno Deb
This doesn't negate your argument that Model 3 may have aerodynamics which could be spoiled (pun intended) by a, er, airfoil... but does add room I think that an airfoil if properly designed and tested could actually improve efficiency (rather than just add downforce to the rear of the car).

 

[Eno Deb]

From the video, I inferred that for the same car, spoiler/wing vs no spoiler/wing, a car would have improved performance over otherwise same parameters. If that doesn't imply improved range or efficiency, I'm not sure what else could except the raw numbers.

He's talking about better racing performance due to more downforce (which improves grip at high speeds), not efficiency.

Cant find the quote from Elon that I was expecting to regarding the Model X spoiler, but here's a reddit thread quoting a thread from this forum, also quoting an article from Car and Driver on a 2010 panamera about how their spoiler deploys at highway speeds to improve drag.

I think these kind of wings are mostly marketing gimmicks. We already know that Elon has a knack for such things (see falcon wing doors). If the spoiler really improved range they wouldn't have dropped the option.

There are some cars though that need more downforce due to aerodynamically flawed body design. Classic examples are older Porsche 911 models (some of which came with gigantic spoilers) and the first generation Audi TT (which got into a number of spectacular accidents early on because it easily lost grip in high speed curves since the rear literally "took off").

 

[skrtskrt]

I wish this was sold as aftermarket. So many lips spoilers out there..

 

[KenC]

I know the thread's old, but I can't resist! The Kammback reminds me of the aero helmet Greg Lemond used to win the TdF in the last day time trial thru Paris to beat Laurent Fignon. Rather than a full teardrop, which wasn't allowed, he used a truncated one.

As far as the OEM spoiler goes, I think it has minimal effect upon downforce, but has a tiny benefit for drag reduction, as turbulent flow may be slightly reduced. Adding a free wing, would increase downforce, but also add drag. You might increase performance on a track by increasing grip (you'd have to add a front splitter to balance that grip), but there's no way you improve range. There's no free lunch. The only place you might get downforce while reducing drag and improving efficiency is from the undertray. In motorsports that's where they would like to get their downforce, but typically, designers are handicapped by rulesmakers. Notice that Tesla has smooth bottoms with undertray pieces. That helps efficiency alot.

Kamm effect or Kammback from Wunibald Kamm wiki:

Aerodynamic theory[edit]
The ideal shape to minimize drag is a teardrop. However researchers including Kamm found that abruptly cutting off the tail resulted in minimal increase in drag.[3] The reason for this is that a turbulent wake region forms behind the vertical surface at the rear of the car. This wake region mimics the effect of the tapered tail in that air in the free stream does not enter this region (avoiding boundary layer separation), therefore smooth airflow is maintained which minimises drag.[9]

Kamm's design is based on the tail being truncated at the point where the cross section area is 50% of the car's maximum cross section,[3][11] which Kamm found represented a good compromise—by that point the turbulence typical of flat-back vehicles had been mostly eliminated at typical speeds.

@Eno Deb
This doesn't negate your argument that Model 3 may have aerodynamics which could be spoiled (pun intended) by a, er, airfoil... but does add room I think that an airfoil if properly designed and tested could actually improve efficiency (rather than just add downforce to the rear of the car).

 

[R1Fast]

From UPs website:

How do we validate our Model 3 aerodynamics products?