F'ing fast.

[tzei]

1 hour ago, visionaut said:

Flatbottom generally aren’t very effective without accompanying aero mods (splitter/skirts/diffuser).

Yes.

[Dudeland]

I suspect it wouldn’t be that hard to make a rear diffuser, or more to the point make something that looks like a rear diffuser,  template it out and use someone like Send-Cut-Send.  But without actually testing it,  it may be pointless. 

[TobyB]

While wind tunnel can  be the most effective, real- time data logging

(from a gopro looking at strings to pressure sensors linked to an inexpensive logger)

can be equally as informative, and a small part of the day-of work for a track day.

I did a low- effort real- time tire temp monitor, and we learned a LOT, later, from having the data.

 

It looks to me like the biggest bang for the buck is just a tall rear 'spoiler', a la Nascar.

 

That said, I run a very lightweight rear shell of a decklid, and if the rear trunk surface was generating

much lift, it'd distort that lid a LOT.  I guess I should video the thing to see for sure, but I've never seen it lifted

noticeably in other people's video of my butt...

 

 

t

not photogenic

[visionaut]

1 hour ago, Dudeland said:

I suspect it wouldn’t be that hard to make a rear diffuser,

Great read by Willem Toet, former Head of Aerodynamics at Ferrari F1.

 

https://www.racetechmag.com/2017/08/willem-toet-explains-motorsport-diffusers/

 

Diffusers are simple in principle - a shaped piece of bodywork containing a venturi with a throat, tunnel and strakes that creates downforce from accelerating the flow of air, lowering its pressure to generate downforce - but complicated to design to fit under a given car. It’s tricky to a) increase volume along the length while b) maintaining attached flow along the tunnel geometry.

 

[tzei]

Somewhat (totally) OT but i think this is cool so i just leave this here.