Let's talk Aero
 

I hit a few track days a year and just got to the point where I'm thinking about aero. For the life of me, I can't find good specific information/recommendations on a base c6. My research has brought me to focus on under body aero though. Since these cars are bottom feeders, there is a huge bottom spoiler to help scoop air. When I'm on track this is literally scraping the ground and not letting any air under the car. This seems like a bad thing but please educate me if I'm wrong.

One of the most advanced sounding products I've found is the LG front splitter and they completely cover up this bottom air inlet. So it seems like they agree that you should have more air under the car. BUT... how much would cooling suffer?
https://www.lgmotorsports.com/track-...-splitter.html

Has anyone dove into aero on their narrow body C6 and willing to give a noobie a lesson?

Not sure what you mean by "bottom feeder" but my first thought is that a Yugo is a bottom feeder. Conversely, a Corvette is at the Top of the Food Chain ... in automotive terms.

Generally you want a low pressure area under the car. The stock "huge bottom spoiler" is an Air Dam, not necessarily to "scoop air." Less air under the car, or any vehicle, means less dynamic pressure for Turbulence to have an effect on Efficiency. This is taken to extremes, but is still the same concept, in really high-tech and ultra-high-performance racing machines where the Aero Effects produce a REALLY Low Pressure area, actually SUCKING the car down onto the track surface.

Having the Air Dam scrape the ground is not necessarily a bad thing, unless it is so low that inordinate Drag results. The Air Dam is cheap and easily replaced. A Front Splitter can be installed ahead of the Air Dam. This helps direct more air up into the cooling/induction Inlet and less under the car. Side Skirts can be installed to further Inhibit air getting under the car and adding to turbulence.

The underside of the car is very uneven, to say the least. It is not streamlined. So the underside causes LOTS of turbulence, and turbulence causes drag. I'm not officially an aerodynamicist, but I have studied the science and the practicalities quite a bit more than most. I design airplanes, have studied wing airfoils, built, maintained and I fly airplanes. The characteristics of low-drag, high-performance aircraft apply to Corvettes much than to other cars, that is for certain.

The Burt Rutan VariEze airplane that I fly is a really good example of the tradeoffs of horsepower increases versus drag reduction methods. The design originally had a 65 HP engine. A Big engine is 100 hp. Mine has a 118 HP Lycoming O-235. It will top out straight-and-level, wide open at about 205 MPH at sea level.

A friend of mine who has since passed away had the 100 HP Continental O-200 on his. But he went to great lengths to reduce drag. His would easily go 250 MPH in the same sort of test. When he pulled back to cruise at only 120 MPH, he got 68 miles per gallon.

The vette is known as a "bottom feeder" because it pulls air into the radiator from under the car. it also scoops up tons of leaves and rocks that clog up your condenser.

You definitely touched on something that's been confusing me. Seems no air would be the most powerful low pressure zone. Obviously that's not possible but if the lower spoiler worked, wouldn't it be much more popular? Everything I see on aerodynamics of a race car is talking about the right air flow, not eliminating it.

That's pretty cool your friend did so much to improve drag and how well it worked. But I'd actually be trying to increase drag and convert that force to, well, downforce. Point very well taken that the bottom of the car is far from a smooth pan but most cars aren't right? does that mean under body aero is useless or just less effective?

Great subject.

The C6 is using bottom air for brake ducting and radiator.
The under carriage is fairly smooth especially under the passenger compartment flooring.
The C7 seems to extend this smoothness with a front undercarriage fairing.

My comment...I'd like to see a C6 rear replacement diffuser.
(With some science showing a downforce increase)
Most I've seen appear more form over function looking nice but, not data.

For a C6 that might be the easiest aero improvement other than a decklid spoiler?

Then there is my comment that all aero must work together.
Front splitter, undercarriage fairings, rocker panel splitter, rear spoiler and rear diffuser.
And of course engine compartment/ wheel wells trapped air causing lift.
And lets not forget vortex generators to reduce wheel well/ rim heat and side drag.

Anyway, great topic.
In for answers.

I removed the chicklets and the door "handles", which gained .0034 mph and nearly.0013 more mpg.
The bigger change was switching from the heavy and turbulence creating front flag emblem to a flag sticker. No one has ever noticed any difference. :leaving:

C5 is a bottom feeder, yes. C6 wide body feeds air to the radiator through the grille. Is the narrow body different? Does the grille do nothing in a narrow body?

That bottom feeder crap on the C6 base is just that, crap.

Katech had some info and basically told me what to do.

I've tracked it since and there is no heat issue at all.

Basically these cars get front end lift so you want to focus on that. Get venting on the hood, get rid of that rubber lip thing, and seal up the bottom, that's what I did with my car.

Check out this thread:

https://www.corvetteforum.com/forums...ro-lift-3.html

In post #133 you can see how I made my own under car aero. Basically I took a piece of cardboard and cut it to the shape I needed. Then I bought a piece of ABS plastic and used the cardboard as a template, and then I attached it. Besides 1 broken zip tie (really been meaning to make some L brackets) haven't thought about it since.

I read all through that excellent thread. Mine is an '07 Base LS2. Do you think that the Block Off piece and the Bottom Sheet/ABS Plate would benefit mine? I really like the idea of removing the stock rubber air dam. Never have liked it. Thanks for the pics, too.

Remember that all that air that goes through the radiator, or pushed up by the air dam, has to go somewhere. If your hood isn't louvered, it will be stuffed right back under the car, lifting the nose. The C6 in stock trim gets real light in the nose at big speeds, though it shouldn't be a big issue at the track.

When you say "thinking about aero", are you thinking you want to slick it up, reducing drag, or, improving downforce to try to improve handling? These are two very different goals, and very different ways to get there.

That's what I'm thinking, and wanted confirmation on, except I cant do the vented hood. Thank you!
That thread was exactly what I was looking for. Lots of great information there, thank you for finding it for us. I'm definitely going to put that same plate in that you did and I'll grab a front splitter when my wallet isn't looking....

For me specifically I'm after more downforce. Just want to grip better in high speed corners.

Under car aero 101

1. Make as little air as possible go under the car
2. Make the air that does go under the car travel as smoothly and as quickly as possible
3. Make the rear of the car channel the air into the low pressure wake created by the car moving through the air to suck the air out from under the car.

How do we do this.

1. Front air splitters and super low ride height.
2. Smooth panels under the car to channel the air
3. Rear diffusers linked to the under panels that increase the surface area at the rear of the car.

This will increase downforce for nearly free and decrease drag.

Just want to add that slamming the car as much as possible might be good for aero, but it's not good for suspension geometry.

Look up some of LG Motorsports posts as he has some very specific dimensions on where to set ride height to maximize suspension performance while getting the car as low as it reasonable.

Can anyone explain the correct rear diffuser design that is needed?

Since my car is now 12 years old I'm not interested in buying a 4 figure diffuser but would will take any easy tweaks I can build or buy. Just not sure what actually works here.

It’s been mentioned already and I know budgets come into play....

https://katechengines.com/street_per...a%20report.pdf

That’s awesome info thank you! According to that, just adding an undertray will do more for front downforce than a splitter. That’s really interesting.

You might also want to add one of the generic spoilers, pick on up used somewhere for a reasonable price. The spoiler increases the hole in the air cut by the car, causing a greater vacuum in the back, and thus pulling more air out from under the car quicker. Basic downforce trick that's been around forever.

Supposedly it is helpful to try to balance out the front and rear downforce, but that is a pain, as typically that takes a wind tunnel. If you DO some high speed cornering after aero changes, you might be a bit careful the first couple passes, make sure the butt isn't lifting or the front doesn't start pushing or some other weirdness caused by the balance of downforce.

Is there a replacement Hood available, or would we install a Hood Louver Kit?

edit:

These might work:

http://trackspecmotorsports.com/shop...e-fender-vents

I'm seriously considering them.

We wind tunnel tested my base model a couple years ago. It was primarily based on drag reduction and preventing me from flipping over at speed!

As mentioned, these cars do have lift from the factory. Hood vents and ride height/rake angle are the first and simplest measures to reduce the lift.

https://www.corvetteforum.com/forums...nd-tunnel.html