Newton06

Someone should perform a study on how many tens or hundreds of thousands of man hours have been wasted on the internet by people bent on trying to figure out just what auto manufacturers are up to.

I'm sure the results would be mind-boggling.

Thousands and thousands of posts on the C8, and all merely speculation.

I wonder if it exceeds the amount of time spent on online ****?

Kodiak Bear

Unless things have changed radically without my notice, racing bodies forbid the use of movable aerodynamic devices. That started when McLaren protested the Chaparral “sucker” car in Can-Am a long time ago. IMO, this device would not be acceptable by the FIA or IMSA and probably not others. The rule enforcement goes so far as to check for “flexing” of body work due to aerodynamic or mechanical loads.

Which raises the fascinating question of when and where would this device be used.

Shaka

That is the question which leads me to believe that the devices depicted in Fig 1,2 and 3 of Patent 2019/ 0047641 A1 below, are for yaw damping and yaw acceleration rate control to augment mechanical AH devices that currently perform that duty. IE: They only deploy at imminent or incipient loss of control. For steady states or transition to other steady states as shown in the Lambo vid, these devices are not necessary to my mind. I'll explain.
Patents don't mean that these devices will reach production.

Keep this notion in mind in your responses. All we are interested in is the efficiency of the friction circle of each tire over a large speed range in acceleration, braking and turning. Race cars have all types of restriction but street cars don't. Street cars are subjected to a variety of roads and conditions even the supercars. Lap times at the Ring and other circuits seem to be important to sports car buyers. In that regard, street car active aero is a lot different to race car considerations. In the Air Force we referred to 'Shadows" that occur in yaw conditions, IE: Shadows at wing roots and engine nacelles.

Things to consider when designing active aero devices for road and track. We will get to each dwg. on this one post in time unless you have other suggestions.

Pros and cons of yaw.

Effects of pitch, roll and yaw.

Each of the following DWGs. A lot to cover.
















Watch the negative yaw on some of the cars on Sunday. Short tracks have positive yaw below.


From yaw to spin
Instantaneous velocity field in yaw
Bump drafting.

Controlling airflow in yaw to minimize shadows.

blipit_

We haven’t seen a C8 testing with any active aero. Could it be we have been seeing the base model this entire time? More potent models and their test mules will follow.

Shaka

Closed for drag reduction only depending on temperatures.

Shaka

I think the high performance cars have this hood outlet. We have seen various rear spoilers that might be exploring the range of incidence for the active wing,



The front active devices are easy to conceal.

elegant

Absolutely. Expect quite a few Z06+ changes in the exterior body. At this time we believe (but not confirmed) that the hood will have two air ducts as rendered many months ago by fvs, the side scoops to protrude around 1/2” more, and additional front, side and rear aero components.

skank

Reading paragraph 0027 of the Patent Publication is very interesting in that it clearly indicates these active vents after the front wheel wells. It the goes on to describe using actuators to push out and deform the body panel by bulging the body surface outward. That indicates the large rear side vents could possibly be used for that in addition to the front vents on the ME. This patent seems to service both FE and ME configurations.

Shaka

The Corvette patent alters the spitter function with this restrictor flap. A, its good for ground clearance, B. It can move the center of pressure for and aft to control push or oversteer functions at the Cg location . C Mass acceleration acts thru the Cg and the C of P is located close to that point. I would prefer that both the lambo and the Vette would move the splitter for and aft and remain level. The Lambo method would be less drag marginally.
The vectoring flaps is BS. Tire grip is paramount and the higher the load the greater the grip. Why reduce it. Yaw is good on oval tracks but road and track is not. Those airbrake things on the patent DWGs is a nasty way to control yaw or even braking. It will make a racket in the first place and the effect on the cars stability will be enormous. It will be banned on track days. Controlling airflow is very effective and Ferrari does it best. They are building a new supercar. The will be vectoring but to allow it to unload the tire is non sense.

I would prefer the splitter to slide for and aft.

Only to arrest high yaw acceleration actively.

Shaka

Trouble with to two outlets on top of the hood, is the hot flow over the fender goes directly into the side scoop. The race car can have this because it will have < 800hp, however, unlike the street version, it will have air to air intercoolers, the placement of those is unknown. The F488's are directly in front of the rear tires.



Hot air over the roof reduces lift and drag over the roof but the rear wing diverts it under the wing which further reduces drag.




I moved the outlets further apart

.



Correct placing of intercoolers. The water to air intercoolers on the streetcar on top of the engine is a disaster waiting to happen. Ferrari has no lag with their IC placing.

John T

The resemblance is curious here. This is one of Shaka’s rough sketches


The similar fascia above the license plate area is on the new Chev Blazer

skank

This side active aero system plays right into utilizing the ZF 4 wheel steering system for lateral force management.

skank

Paragraph 0029 describes the use of the system immediately behind the front wheel well to exhaust the heated air from the hot brakes. There are quite a few locations within the entire publication that describes these moveable planar surface vents aft of the front wheel well. These would work very well in FE configuration, where the ME does not have near the available space to accomodate a large blade. Not saying that a ME wouldn't work, just that it's optimum in a FE.

Shaka

An active 4 wheel steering system negates any augmentation from aero devises. Keep the air attached on all surfaces to prevent any shadows and keep the downforce as high as possible. In other words, control yaw. That is not to say active aero doesn't have a place in street autos but it is usually for drag control. If you can make it do other things, so be it. If anything, you would increase the load on the inside wheels. Splitters or front and rear diffusers require ride height control. The active side skirts are really great for this type of control. Here is the fastest street Vette in the world. I did the aero.

OnPoint

You work for Johnny Bohmer?

ZMMMMM

Here is the Zenvo TSR-S with a crazy tilting rear wing...

Shaka

No, I consulted him on this project upon his request. It was tested in a NASCAR wind tunnel. This is as far as I could go to comply with the rules. The spoiler box has less drag than the coupe.

Shaka

Interesting. The lift vector is perpendicular to the span therefore the effective load moves in the direction of the turn. It is the reverse of an aircraft wing. The rudder doesn't turn the plane the lift vector does.

OnPoint

Ah, interesting. I've got over 150 runs in mile events, most of which have come at the Texas Mile. I know this car/seen it run there. Johnny did a nice job on that rig - particularly considering the apparent basket case it was when it was first brought to him.

I remember the hood incident on one their first runs with the car after reworking it.

Shaka

Very cool. Johnie's shop is just about on the PBI property.