Miata Turbo Forum - Boost cars, acquire cats. - Aerodynamic Discussion Thread

- Aerodynamics (https://www.miataturbo.net/aerodynamics-119/)

- - Aerodynamic Discussion Thread (https://www.miataturbo.net/aerodynamics-119/aerodynamic-discussion-thread-70612/)

Most auto-x guys you see are running spoilers because thats all the street prepared or DP rules allow. My wing actually makes downforce below 45mph where the spoiler isnt noticable, make way more downforce at any other speed, and it makes less drag at all speeds than an SP spoiler. That corvette spoiler cost him about $70 for the piece of lexan and nearly $100 in fasteners. Yeah you can home depot something with luan and heavy steel shit from home depot for more like $60, but ass it will look like.

Fantastic photos!

Porsche GT1 mmmmm, nice!

Quote:

Originally Posted by mx5-kiwi (Post 1190123)

Fantastic photos!

Porsche GT1 mmmmm, nice!

I also took picks of the 918 and 918 prototype, but no aero pics of them so I didn't add them

Some of those photos caused me to inadvertently let out some sexual noises in my office. Hope nobody heard.

Great pics. Thanks for posting.

Quote:

Originally Posted by mx5autoxer (Post 1190531)

https://www.miataturbo.net/attachmen...ine=1418954126

Was ist das?

Adjustable plane diffuser? Since that car is going for drag reduction over best traction, the vanes probably adjust based on speed to give the best Cd...my guess.

Quote:

Originally Posted by mx5autoxer (Post 1190531)

https://www.miataturbo.net/attachmen...ine=1418954126

Was ist das?

Quote:

Originally Posted by cordycord (Post 1190533)

Adjustable plane diffuser? Since that car is going for drag reduction over best traction, the vanes probably adjust based on speed to give the best Cd...my guess.

Ya that was the best pic I could take since the car was to low and it was up against the wall.

That is an airfoil. In the downforce orientation..

Interesting that that whole diffuser assembly is made up of identifiable materials that certainly don't fall into the category of OE BMW level construction.

-Ryan

The diffuser fins were made of rubber instead of metal or composite

https://www.miataturbo.net/attachmen...ine=1418823278

Quote:

Originally Posted by mx5-kiwi (Post 1190123)

Fantastic photos!

Porsche GT1 mmmmm, nice!

I have to wonder how much that aero design would change if it didn't matter how it looked. I have to assume a design emerges after a knockdown dragout between aerodynamicists and stylists. But yeah, I sure do admire the result.

I will probably do the bottom of my diffuser fins in ABS or rubber/conveyor belt material so it won't get destroyed on rough courses.

Quote:

Originally Posted by cordycord (Post 1190533)

Adjustable plane diffuser? Since that car is going for drag reduction over best traction, the vanes probably adjust based on speed to give the best Cd...my guess.

Interesting. So, like an airfoil, this is likely an adjustment for the diffuser that optimises for a certain speed (in this case, like you said, only taking into account low C/D instead of a balance between C/D and downforce). I guess I never realized that it could be tuned like that. Has anyone seen anything like this in a racing class or would that be considered moveable aero (whether or not its tunable on the track or in the pits)?

And btw I looked, but couldn't find any info on this because every bit of information out there is focused on the hydrogen engine instead of the aero.

I'm not seeing anything in that photo that implies that the airfoils adjust as anything more than fixed position. However, Andrew Brilliant runs an underbody wing in lieu of a traditional diffuser.

https://www.miataturbo.net/attachmen...ine=1419010104

I do wonder if there is a benefit to a "wing" underneath the car, as opposed to the more traditional diffuser, especially on cars that don't have a perfectly flat bottom to feed the wing. I know mounting a wing under the ass of my car would in my case be an easier install than a more traditional diffuser, and the increased ground clearance would be a welcome addition...

Would aid in airflow re-attachment too wouldn't it? (drag reduction...)

As an addition to the rearward part of a diffuser which is creating nice laminar, smooth flow to the airfoil, I like it. I like it less as an independent element just hanging out under the bumper. An airfoil relies on airspeed. Turbulent air is slow.

-Ryan

Are you sure that's a wing element? I'm looking at the picture on my phone, but I'm not seeing it. Looks like a typical diffuser to me.

Quote:

Originally Posted by jpreston (Post 1190746)

Are you sure that's a wing element? I'm looking at the picture on my phone, but I'm not seeing it. Looks like a typical diffuser to me.

Yes, to both photos. On AB's car, it's suspended between the two vertical strakes. Bit dark, but you can still make out the end plates and all.

Spoilers create a great deal of drag as a consequence of the downforce. This is bad on track. Much less significant at auto-x speeds.