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Old 11-12-2020, 05:40 AM   #41 (permalink)
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Since you guys evidently know your stuff, is this type of upward sweep on a tail detrimental to airflow? I assume air could come up off the bottom and push upward, creating unnecessary downforce. If it’s a useable shape, I’d LOVE to use it on my car in the future.

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Old 11-12-2020, 10:15 AM   #42 (permalink)
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Quote:
Originally Posted by JacobLeSann View Post
Since you guys evidently know your stuff, is this type of upward sweep on a tail detrimental to airflow? I assume air could come up off the bottom and push upward, creating unnecessary downforce. If it’s a useable shape, I’d LOVE to use it on my car in the future.
https://ecomodder.com/forum/showthre...gle-17673.html
Quote:
4-degrees
The air will not be attached, but as illustrations show the path to re-pressurization is there (hole in air the car leaves behind it).

https://www.racecar-engineering.com/...-aerodynamics/


I guess if you need a great departure angle go for it.

The Bonneville style rear deck extensions didn't have much there because I assume they were so low to the ground, not much flow under the car.

I think this departure diffuser angle subject will only be relative with full belly pan.


REPOST:
84-89 3.2L upgraded to 3.5L with 267 Wheel HP! - Pelican Parts Forums


With tray off, looks to be full carbon fiber belly pan to the front.

84-89 3.2L upgraded to 3.5L with 267 Wheel HP! - Pelican Parts Forums
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Last edited by kach22i; 11-12-2020 at 10:21 AM..
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Old 11-12-2020, 12:44 PM   #43 (permalink)
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Noted. Interesting, I’ll look into that. You’re probably right about the Bonneville cars. The Blowfish, one of my all-time favourite pieces of art, doesn’t have a boat-tail, which wouldn’t make sense were it not that the car is low enough. It makes sense to me.

I have no knowledge about those rear diffusers, so I’ll look into that. A full belly pan is what I’d like to get done first, before it’s road salt season.
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Old 11-12-2020, 01:11 PM   #44 (permalink)
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What would happen should you put lower side extensions on the wing, making a partial Kammback? Wouldn’t it be better? My car has a lot more underbody flow than a Bonneville setup.
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Old 11-12-2020, 01:12 PM   #45 (permalink)
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Quote:
The Blowfish, one of my all-time favourite pieces of art...
For those following along at home:


https://www.thetruthaboutcars.com/wp...a-ad-image.jpg

I took this at Bonneville:



O'course, I also saw this:



The car you showed at Permalink #41 was discussed at length here at one point, but I have an appointment across town, so I'll have to check back.
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Old 11-12-2020, 01:43 PM   #46 (permalink)
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Woah! When you can, lemme know any and all details on that second pic. Dream car, hands down.
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Old 11-12-2020, 03:35 PM   #47 (permalink)
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If I’m already set on a wing, why don’t I carry the sides down and make a partial Kammback? Or does it not help? Thanks in advance for any clarification.
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Old 11-12-2020, 04:49 PM   #48 (permalink)
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Thanks for asking.

I won't clutter the thread, your search term is duckduckgo.com/?q=stupidbaker

A Kamm-back is top half of a boxed cavity. It's useful on notchcbacks.

A wing is free-standing. An example might be the Charger/Daytona towel rack. It's more rudder than elevator, they're supposedly spin-proof. When you get to F1, they have massive end plates, because rules.

What might work well on a Civic would be a reverse sail panel the rolls inward to match the tumblehome of the cabin, similar to the Bertone BATs but with an active airfoil wing pace JulianEdgar above the sightline to the rear.


edit:
Incautious speculation: The towel rack is an example of an external duct — the BAT is not, any more than a 1959 Chevrolet. As an external duct, it should be possible to accelerate the air and inject a jet to the wake that would entrain and organize it. Once again GTI W-12 650.
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Old 11-12-2020, 04:59 PM   #49 (permalink)
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Quote:
Originally Posted by JacobLeSann View Post
If I’m already set on a wing, why don’t I carry the sides down and make a partial Kammback? Or does it not help? Thanks in advance for any clarification.
I'm confused, so I will post some images to go with certain terms of phrases.

Box Cavity:
https://ecomodder.com/forum/showthre...k-26367-2.html


https://ecomodder.com/forum/showthre...uck-26367.html


Kammback
https://www.metrompg.com/


https://ecomodder.com/forum/showthre...oat-24419.html


Wing
https://www.carid.com/duraflex/custo...r-spoiler.html


Rear Spoiler: Bonneville-style rear deck extension
https://ecomodder.com/forum/showthre...any-10434.html


Not to be nit-picky but words can mean one thing to one person, and another thing to another person.

A wing is up and into the airflow, a spoiler interrupts said flow, a Kammback is like a fastback only more so because it maintains air attachment and isn't just a styling statement, and a Box Cavity may overlap with several of the preceding terms but in short distinguishes it's self with an absence or negative space.

It sounds like you want to build a "Box Cavity" and should call it that.

Not as exciting sounding as a "wing" but that's the marketing department's problem.

You could say your Box Cavity is an open ended Kammback if it's like that white VW van - the very first image.

Everyone would be quite confused until you post a picture though.

The bottom image is a rear spoiler, box cavity and has vertical wing stubs (stall fences if on aircraft).

Now I'm back to being confused?
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1998 Chevy S-10 Pick-Up truck
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Chin Spoiler:
http://forums.pelicanparts.com/off-t...effective.html

Rear Spoiler Pick Up Truck
http://forums.pelicanparts.com/off-t...xperiment.html

Roof Wing
http://ecomodder.com/forum/showthrea...1-a-19525.html

Last edited by kach22i; 11-12-2020 at 06:40 PM..
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Old 11-12-2020, 05:31 PM   #50 (permalink)
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(What kach22i said) I can't remember the thread where that car in #41 was discussed, having thought about it.

But... I got to thinking about what went down in 2013.

ecomodder.com: Project: ECOfamily Civic and its Aero Hitch Box / Boat Tail

The box is another subject but the Kamm-back had it's up and downs (oops punagain). The adventure is at #202. Magnets. How do they [not] work?

I wanted to point to #171 through #184. Here's the money shot:



Today I'd say spotwelds or Unispot studs instead of magnets. No holes, just spot paint if the hinges are removed.

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Last edited by freebeard; 11-12-2020 at 05:37 PM..
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