Evolving Aero: Here are my tentative plans for aero. I figure once I get all of this stuff together, I can do a test day and collect some quantitative data on what works and what doesn't have much affect by taking bits on and off for each session.
Rear wing: I ran this with an angle of attack at near 0 degrees in the center. APR says this makes ~240lbs of downforce and ~27lbs of drag in open air (not behind a car) at 100mph. That is a lift to drag ratio of almost 8.9:1. Changing the AOA to 5 degrees ups those numbers 290/36 for a ratio of 8.2:1. Less efficient but more downforce. 10 degree AOA nets 317/45 for a ratio of 7:1.
https://aprperformance.com/racing-pr...ustable-wings/
Because this is a “twisted” wing, the ends are actually 15 degrees steeper than the middle. This means that when the center is set to 0, the ends are already approaching stall conditions. When a wing stalls, downforce no longer increases(much) with AOA, but drag does.
I will probably continue to run 0 AOA for now, but I may increase it to 5 degrees if I feel the need to apply more rear aero balance. That will depend on the ......
Splitter: I was happy with it, but I can only guess at what sort of downforce it made. Maybe 100lbs? If I’m lucky. I have a plethora of ideas to improve it. More contoured shape, lighter weight, tunnels, end plates, and more rigid mounting.
Contoured Shape: this comes from (again) watching too many AJ Hartman videos. He has some great details on how a wing shape is better at generating downforce. One way to cheat the wing shape is to simply add a very long bevel to the front edge and then increase the splitter angle to between 2-4 degrees with the front being lower. This would be simpler but wouldn’t quite be the same since the leading edge is not a straight line. This leads me to…
Lighter Weight: This can be achieved by making the whole splitter body out of carbon fiber with a foam core. The foam core can be carved and shaped to create a wing profile before being wrapped in carbon and infused with resin. I had started making plans for this but then AJ Hartman released his splitter for the Camaro. I was ready to hand over my first born but….
Tunnels: It didn’t have tunnels! Splitter tunnels can double the downforce of a splitter by creating a void the air will try to fill. Filling that void causes a low pressure region. (At least that’s the simple explanation) There are a ton of articles about the benefits of splitter tunnels. The big problem though? The Camaro has the Aux radiators right where you would want to stick a tunnel. This really limits the size of the tunnel. I actually talked with AJ about it and he wanted to keep the kit simple for now. He thought it would take a good bit more work to make tunnels to fit, and he thought the wing shape was more important for the time being, as he doesn’t have any actual wind tunnel data for the Camaro.
End Plates: I am continuing on my journey of creating my own carbon fiber splitter. But because AJ was such a nice guy, I decided to buy a set of his splitter end plates. In another video, he talks about how they can add an additional ~50 lbs of downforce by sealing the high pressure zone at the edge of the splitter and generates cleaner vortices. They are a fairly complex shape and I figured it was not worth the effort of me creating them when he has such a nice (and thoroughly tested) set available.
https://ajhartmanaero.com/low-drag-s...r-side-plates/
Back to the (future) tunnels. I also bought a 3D printer with the idea of making some bits and pieces for the Camaro(and a bunch of silly toys for my kids). I watched a couple more videos and write ups and decided I could probably design a tunnel shape to fit under the aux radiators and 3D print a mold to lay carbon in. Well, I realized that I would need to print the plug to make a mold. and that it would be larger than my printer's capacity...... I’ll create another post dedicated just to this.
Revised mounts: The last thing for the splitter, is mounting it more rigidly. I bought a set of the rear brackets from AJ to replace my elevator bolts(probably still going to run elevator bolts just ones that thread into his mounts), but I also reinforced the trans cooler mounts by running a piece of flat aluminum from the rear trans cooler bolt to the innermost tab on the aux cooler duct mounts. This really reduced the lateral play in the whole trans cooler mount. I will likely also have to revise the lateral mounts, but that will have to be figured out after the tunnels are installed.
Canards: I had to trim these to fit around my vent covers and thought why not use the cheap plastic ones as templates to make some out of carbon fiber. I also figure I can make a couple versions. The ZLE ones have such a steep angle that I have no doubt that they are contributing to the drag on the car. I am going to try to make some smaller half size canards to see if I can still get a little downforce without as much drag penalty.
Tire blockers: With a 3D printer, I also thought I could model a tire blocker for the front since the 305s have a little poke to them. At the bottom of the bumper(just above the 1LE lip, you can see about 2-3 inches of tire face. I thought this would be a great way to learn a little about CAD modeling and explore the benefits of rapid prototyping with a 3D printer! I could also make some for the rear tire as they poke a little as well. More to come on those as well.
Upper grill block off and radiator ducting: I saw Lewisracing's thread on his NASA ST2/ST3 build and liked the upper grill block off and rad ducting idea. It should be simple enough to make a piece of carbon to fit across the upper grill. I haven't decided how I want to do the ducting but I have a couple ideas. I pulled the upper radiator block-off plate that also provides mounting for the bumper. I might try to remake that out of carbon fiber. That will save a few pounds. Or I could delete it and create a different shroud/duct plus bumper brackets that mount to the crash bar. I am also thinking about leaving part of the upper grill open and making an inlet for air to feed to the intake. I also just saw another local 6th gen guy on FB make an OTR intake using a C6 corsa system. We'll see where I go with this..
That about sums up my ideas for improving the aero parts. Lots of stuff to do and figure out. Thankfully(kinda) the season here in the PNW doesn't really start until May. So I've got time to figure things out.