Trunk Wing Spoiler

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Gorillapaws

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#3
Looks interesting but I'm not sure if I want to mess with the aerodynamics of a car that so much work went into keeping the CD low.
I have to second this. I mean how much down force could this car possibly need when it's floor is packed with batteries? I'm guessing this is 100% for aesthetics--which are subjective to be fair.
 

Rich M

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#4
Looks interesting but I'm not sure if I want to mess with the aerodynamics of a car that so much work went into keeping the CD low.
I'm thirding this. This car is all about Cd, and the stability control system is excellent to the point where you'd never have to worry about the tail coming out due to lack of down force. The car is so heavy that even if a spoiler could make a difference it would have to be huge. Aesthetically, why add a huge sail to kill range and burn up kWh?
 

Rich M

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#6
I think the wording is bad here. The word "wing" should be nowhere near the type of spoiler pictured above. I like the T-Sportline spoiler and that little thing isn't going to mess with your aero much. "Wing" implies the spoiler is separated from the body (i.e. you can put your hand under it). Most people I know would call what's in the photo a trunk lip spoiler.
 

oneshortguy

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#7
I think the wording is bad here. The word "wing" should be nowhere near the type of spoiler pictured above. I like the T-Sportline spoiler and that little thing isn't going to mess with your aero much. "Wing" implies the spoiler is separated from the body (i.e. you can put your hand under it). Most people I know would call what's in the photo a trunk lip spoiler.
Included 'Wing' since not everyone knows the difference.

It is more or less a T Sportline Model S spoiler (best looking Model S trunk spoiler in my opinion), but for the Model 3. It's definitely going for that OEM plus look. Drag for something like this is negligible.

Here is a T Sportline Model S spoiler for those who don't know:

midnight_silver_metallic_p100d_21_inch_ts114_wheels_custom_ferrari_creme_interior_6-1280-jpg.5253
 
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#9

Gnarly.

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#11
Just fyi: The main point of a spoiler isn’t neccesarily to create raw downforce but to redirect/decrease unwanted airflow that would create lift (low pressure) and turbulent drag at the rear edge of the car. I have a small trunk spoiler lip on mine and plan on getting this one asap. Imo, shouldn’t hurt anything (it’s pretty small) and there’s a fair chance it’ll help overall if the spoiler has been designed well.
 
Last edited:

Oregonian

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#13
Just fyi: The main point of a spoiler isn’t neccesarily to create raw downforce but to redirect/decrease unwanted airflow that would create lift (low pressure) and turbulent drag at the rear edge of the car. I have a small trunk spoiler lip on mine and plan on getting this one asap. Imo, shouldn’t hurt anything (it’s pretty small) and there’s a fair chance it’ll help overall if the spoiler has been designed well.
Does anyone have a source to help determine if this would actually help or hurt drag?
 

c2c

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#14
Does anyone have a source to help determine if this would actually help or hurt drag?
http://dl.kashti.ir/ENBOOKS/NEW/FDD.pdf
This is “Fluid-Dynamic Drag” by S.F. Hoerner, 1965.
Dr. Hoerner is a titan in the history of wind tunnel testing.

As noted earlier, the Model 3 is not likely to need any down force to improve high speed traction.
The edge of the trunk is in the wake of the roof, so the device will be in turbulent air.
There is additional skin friction drag that helps nothing.
And the seams of the device’s leading edges are likely not blended with the trunk, adding to the drag.

It would be more beneficial to write “FASTER” on the trunk than to bolt this thing on.
 

Oregonian

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#15
I'm not talking about improving downforce for traction, I'm talking about reducing drag for energy efficiency.
http://dl.kashti.ir/ENBOOKS/NEW/FDD.pdf
This is “Fluid-Dynamic Drag” by S.F. Hoerner, 1965.
Dr. Hoerner is a titan in the history of wind tunnel testing.

As noted earlier, the Model 3 is not likely to need any down force to improve high speed traction.
The edge of the trunk is in the wake of the roof, so the device will be in turbulent air.
There is additional skin friction drag that helps nothing.
And the seams of the device’s leading edges are likely not blended with the trunk, adding to the drag.

It would be more beneficial to write “FASTER” on the trunk than to bolt this thing on.
 

Oregonian

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#17
If such a simple change resulted in better efficiency, I've got to imagine that Tesla would have already incorporated it into the Model 3.
You don't think they decided on what they liked as a compromise on efficiency and aesthetics. I don't think that what you see on the model 3 is the best you can get for aero on a trunk lid. I'm just trying to see what can improve it.
 

c2c

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#18
I'm not talking about improving downforce for traction, I'm talking about reducing drag for energy efficiency.
If you look through Hoerner's pdf, you will see example coefficient of drag results of cars and car parts, like fenders, fairings, sloping rear ends.
Just like the results of simple 2 dimensional bodies, a slipstreamed front end can reduce drag. A tapered rearend can reduce drag. If you cut the slipstreamed car in half, about where the B pillar is, but keep the 2 pieces very close, the drag remains about the same.
As you separate the 2 pieces, the drag of both increase. The tail reduces the wake of the front, but as more of a gap allows more air to swirl about, the front needs to work harder for the same speed.
Alternatively, if the rear taper is very short, the flow separates from following the rear's surface, creating a bigger wake, pulling more air along with the car, and that takes energy that increases drag.
So there are only a couple ways to decrease the model 3 total drag.
You could draft behind another vehicle, like a UPS van. Visibility sucks and the paint job gets hit by road debris.
Or have that UPS van tailgate real close to essentially push you model 3 by improving the 3's tail performance. But that van is unsafe and the energy savings for the 3 is way less than the cost of running the van.
But a tab that tips the upper surface air up, thereby reducing total drag, will not withstand experimentation. That tab will increase the size of the wake, robbing the model 3 of energy.
But don't take my word for it. Thumb through Hoerner's impressive work.
 

Gnarly.

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#20
Side note: You can see what appears to be a pseudo "spoiler" or extended flat lip from the Model 3 trunk edge/lip (looking at the side) which would be one of the cool little design elements Tesla has engineered into the car.

I wish I had a wind tunnel or massive program/computer to do CFD but at this point, the Model S spoiler's angle of attack is so low I'm assuming Model S nor the Model 3 doesn't really need one (because of diffusing action from under the car), but still can benefit from one. I can't verify this but simply have an extended lip/edge at a low almost flat angle would simply offset the point where turbulence and low pressure pocket of air forms and slightly farther back. Remember, just because a spoiler is almost pointed upwards doesn't necessarily mean it's a hard block that'd cause totally stoppage of air aka a parachute. In fact reason you get better mileage with your pick up truck with the tail gate up than down is because that lift gate creates a pocket of air and air flow at speed subsequently flows over this cushion of air from the cabin then over the raised lift gate contrary to common sense. This is the reason I believe none of us can automatically say a spoiler will cause a determent to efficiency/speed and why I'm saying it's probably a net bonus (extremely little). Spoiler is to redirect or offset where the low pressure pocket of air (and drag) would form and thus cause a lifting effect from the back end. This is more complicated than just quoting some person. Hypothetically a person who makes use of the top speed all the time with a decent size extended spoiler lip would likely benefit as it'd increase rear stability and keep it planted. Yes, there's a point where the pitch angle of the spoiler would outweigh the added drag felt at lower speeds but if TSportline does a decent job of just rough calculating the numbers, angle, simulation here and there, etc it could be of a benefit for people who drive 75-100mph+ consistently.