So, I am finally creating a thread after 50 years of not understanding anything about ground effect aerodynamics from the limited reading I've done from magazines. Mostly for street cars but open to any and everything whether sanctioned, outlaw, or just theoretical. It all started with the AJ Foyt driven 1987 Oldsmobile AeroTech.
www.car-revs-daily.com: 1987 Oldsmobile Aerotech 
Is there a way to create wing-tip vortices behind the front wheels to help evacuate the air under the car?
Maybe something based on the knowledge off this stuff?
Here is what I have come up with my limited knowledge untill 1985:
I'm not the expert here, but what I see in your designs are sort of the natural evolution of ground effect aero from the late 70s into the 80s.
What they found was that bigger wasn't always better - an entire car shaped like a wing was not only pretty draggy and killed straight line speed, but that they tended to have undesired effects, such porpising due to generating so much downforce that the bodywork sucked to the ground, stalled, then popped back up, lather, rinse, repeat. Not a fun way to get down a long straightaway (maybe we'll cover the Ligier F1 scandal of 79/80 later). Chassis and suspension components weren't great at handling huge increases in load and tended to fail, sometimes in dramatic fashion.
I'd suggest to you look at current IMSA and FIA WEC prototype and GT cars for ways to deal with ground effect/diffuser aero and tires with full car bodywork. In particular, take a good look at and consider the Aston Valkyrie, which has a lot of input from Adrian Newey, and because it's derived from the road car (which he also much of the work on), is less subject to rules limitiations than the others (e.g. height of the exit tunnels).
- Bill C
In reply to BillCuttitta :
Thanks for that info, I am stuck in the 70's. I always thought that the porpoising issue was because of the flat bottom rule for all of those cars and the fact that whenever they hit a small bump, the car would oscillate between negative and positive angel of attack with regards to the flat bottom and the ground, growing worse until eventually sending them airborne.
I wonder what those curly things on the edges of the front splitter and rear wheel winglet do? Underbody vortex generators?
You have to remember that I want to build a street car and the 8 wheeler design is something I could actually build in my garage if I had a few key pieces of shop equipment like a tube bender, notcher, and brake. And somebody would design me a double A arm suspension.
Wikipedia.org: Aston Martin Valkyrie
VolvoHeretic said:
In reply to BillCuttitta :
Thanks for that info, I am stuck in the 70's. I always thought that the porpoising issue was because of the flat bottom rule for all of those cars and the fact that whenever they hit a small bump, the car would oscillate between negative and positive angel of attack with regards to the flat bottom and the ground, growing worse until eventually sending them airborne.
I wonder what those curly things on the edges of the front splitter and rear wheel winglet do? Underbody vortex generators?
They help direct air around the tire to decrease what is referred to as "tire squirt" or at least that's how it was described in relation to F1.
In reply to wvumtnbkr :
These are kind of dated pictures of the AMR Valkyrie street car, but essentially still valid.
Those scrolls are indeed to reduce 'tire squirt' and I understand can help provide a bit of an aero seal along the sides of the car for the front and rear negative pressure sections in the center of the underbody.
- Bill C
I was thinking I could maybe build a couple of up curved delta winglets starting from behind the inside of the front tires to in front of the outside of the rear tires based on the upside down delta wings of the F-106 Delta Dart which create their lift by riding on leading edge vortexes. I think.
We have one sitting at our airport, I will drive up there and see if I can get a few better photos of the wing.
Even though the van suspension was lowered, the addition of the 19'' wheels and 245/40 tires has raise the van back up to and above a normal ride height. I was considering the 1'' or 2'' gardening trim along the rocker panels.. but will wait to see when my buddy installed the front splitter.
