Flat Bonneville-type spoiler

[AeroModder]

Coastdown testing shows a slight reduction in speed, but that's also due to the fact it's getting quite cold out.

The airflow definitely reattaches onto the spoiler, and I noticed that the naturally occuring counter-rotating vorticies off the sedan shape become apparent. I was driving without VGs after realizing they're useless in crosswinds and noticed similar patterns in the dew even without them, but further down.

With the vortex generators positioned like \\\\\///// (as opposed to the standard
/////\\\\\), there were two high-pressure zones present at the base of the rear window:

   Cabin
___________
 /|\   /|\    

 Decklid

(The /|\ lines show the directions of flow.)

I noticed the same spreading high-pressure pattern start about 5 inches before the edge of the decklid (at the beginning of the spoiler).


I was thinking about taking the side pieces of my partial kamm and putting those on to give the air off the sides a vertical surface to detach from, hopefully stopping the vortex generation.

[cfg83]

Aeromodder -

You can use the "Code" wrapper ("#" symbol) to preserve spaces and use a mono-space font :

    Cabin
 ___________
  /|\   /|\ 

   Decklid

CarloSW2

[AeroModder]

Thanks, I'll remember that.

[HeadlessNorseman]

would something like this work on a crx style body as well to smooth the airflow off the passenger compartment and fromt the sides together? or would the sloped down kamback style work better?

[UFO]

I am not sure the flat spoiler is very easy to implement on the CRX style body. It looks to me you would have to go to a boat tail to improve on the CRX.

On the other hand, with the VW New Beetle with a steeper rear slope, Ernie Rogers effectively demonstrated the flat spoiler style works well. I am looking to duplicate his results on my Beetle.

[AeroModder]

The fuel attendant topped off the tank, so it went past the F mark by at least a gallon. The tank was around 26ish, but I'll average it in with the next couple tanks.

Testing changes at the turn of the season isn't the best way to do things.

[AeroModder]

So far, the average with the spoiler is about 27.7 MPG, and that's including some bad weather and a fair bit of city driving.

After the fillup, the needle was slightly below where it normally falls. The wierd thing was that it was about a gallon's worth lower the next time I turned the car on.

I'm starting to think seeing regular 30 tanks in this car might be a bit out of reach.

[Cd]

AeroModder, have you tufted your car yet ?
I'm guessing that you are having a lot more turbulence at the back glass versus the Fusion, due to the steeper angle.

Are you positive that the flow is re-attaching ? ( I'd guess yes - but that not enough of it is re-attaching to really make a big difference. )

I certainly do like the look of it !
If you're not seeing much attached flow, I wonder if it would be beneficial to raise it up several inches to where it meets the rest of that airflow.

[AeroModder]

I'm positive it reattaches. It's been a bit wet, but I'll see if I can tape on some tufts and see what the flow looks like when I take my fiancee to work.

I also found a '92 Civic VX hatch for sale for $2k... Seriously considering a trade-in.

[alohaspirit]

i remember discussing the Bonneville-type spoiler almost a year ago


am really interested in any results you can muster