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Old 03-31-2022, 08:18 PM   #21 (permalink)
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For those following along at home : hypereconiq image and link
the rear spoiler doesnt make much sense to me though. it increases the wake area. if anything, it should slope down lower to reduce the wake, then flip up at the end, without going above the height of the original wake area line

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Old 04-01-2022, 07:50 AM   #22 (permalink)
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the rear spoiler doesnt make much sense to me though. it increases the wake area. if anything, it should slope down lower to reduce the wake, then flip up at the end, without going above the height of the original wake area line
I can't comment on the specifics because I have never seen that vehicle, but it is always possible that the increased wake area and differing recirculation actually reduces drag.

By increasing the height of the rear spoiler it may reduce drag from the underside, increase flow under the car, reduce drag at the corners where the side meets the back etc.

Last edited by AeroMcAeroFace; 04-01-2022 at 10:14 AM.. Reason: adding etc. there are many reasons that I didn't mention, due to space and knowledge limitations.
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Old 04-01-2022, 08:18 AM   #23 (permalink)
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Originally Posted by AeroMcAeroFace View Post
I can't comment on the specifics because I have never seen that vehicle, but it is always possible that the increased wake area and differing recirculation actually reduces drag.

By increasing the height of the rear spoiler it may reduce drag from the underside, increase flow under the car, reduce drag at the corners where the side meets the back.
Exactly--there's much more going on than wake area. The flow around cars is three-dimensional, complex, and not possible to predict using simple principles. This isn't me arguing this; look in any textbook. For example, RH Barnard, 2009: "There are no straightforward methods for predicting how air will flow around a given shape." It's literally on the first page of the book!

A spoiler can also reduce drag and lift by increasing pressure on the surfaces ahead of it.
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Old 04-01-2022, 12:06 PM   #24 (permalink)
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I’m also shocked they didn’t use any aero wheel covers. Yeah they carbon fiber wheels look nice and shiny, but in terms of aero, there’s no way they are helping
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Old 04-01-2022, 12:23 PM   #25 (permalink)
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Someone posted it and I've already forgotten which one, but a recent concept car has a concave spoon-shaped depression ahead of the spoiler to add downforce without increasing the drag.

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Old 04-01-2022, 03:37 PM   #26 (permalink)
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The two main things I thing would be easiest to do would be to make a smooth undertray ( girlfriends mom is a professional welder so it shouldn’t be too hard) and then a rear wheel spat that looks cool and OEM and could be removable. I’d also like to someone make the back of the car have a box cavity type styling with the edges going slightly inwards to reduce the wake. Not going to go the full boat tail route for practical reasons.
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Old 04-01-2022, 03:50 PM   #27 (permalink)
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It comes down to how the bellypan and difusser transition into the boxed cavity.

I saw this at Bonneville Salt Flats:



I could've got a better angle but I never saw it again. The skegs flare out from inside the tire to flush with the outer face. I think this would keep the turbulence in the wheelwell from migrating into the underbody flow, and provide fencing to the difusser.
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Old 04-01-2022, 04:26 PM   #28 (permalink)
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It comes down to how the bellypan and difusser transition into the boxed cavity.

I saw this at Bonneville Salt Flats:



I could've got a better angle but I never saw it again. The skegs flare out from inside the tire to flush with the outer face. I think this would keep the turbulence in the wheelwell from migrating into the underbody flow, and provide fencing to the difusser.
yeah i definitely need to do a smooth belly pan and rear diffuser first before i do the other more difficult mods
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Old 04-01-2022, 04:28 PM   #29 (permalink)
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heres the porsche 935. the box cavity looks amazing. plenty of other images online too
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Old 04-02-2022, 09:44 AM   #30 (permalink)
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The two main things I thing would be easiest to do would be to make a smooth undertray ( girlfriends mom is a professional welder so it shouldnt be too hard) and then a rear wheel spat that looks cool and OEM and could be removable. Id also like to someone make the back of the car have a box cavity type styling with the edges going slightly inwards to reduce the wake. Not going to go the full boat tail route for practical reasons.
Those all sound like a good starting point. Build them out of cheap, disposable materials first and test them. Every time I test, I am surprised at what works that I didn't think would work, and what doesn't work that I really thought would.

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