Notchback Rear Aero / Big Wing

[Series8217]

and the wing stands from the water jet vendor.

I'm also thinking about milling some nicely profiled pockets into the stands to reduce the weight a bit. They're ~4 lbs each right now, but there's a lot of extra material in the middle for cosmetic purposes only.

Steel?

Feature creep... should have had the water jet guy do the weight relief

3/8" aluminum.

Water jets can only cut all the way through. I could not come up with a skeletonized or thinner design that looked good - that's why I would be milling pockets and not cutouts. The stands will still look solid.

[The Dark Side of Will]

I think if it's light weight it looks good

[crzyone]

Speed holes.

[Series8217]

I think if it's light weight it looks good

Well, my other excuse is more profile area for moving the aerodynamic center toward the rear to increase directional stability.

[Series8217]

The new wing mounts and endplates:


The camo pattern is just because of some vinyl samples I had from another project.

[Series8217]

I forgot to post my downforce / drag calculations for the NASCAR COT wing. The coefficients were generated using the airfoil coordinates from Airfoiltools.com for the LNV109A plugged into JavaFoil.



Updated 2014-05-17 to fix the drag calculation (the drag is less than the previous version showed it was).

Note that this is the force generated by the wing, not the actual additional force at the tires, which is higher due to the lever arm. There is no vehicle-specific data in these calculations. Also this data does NOT include a simulation of the gurney flap which extends ~0.5" up from the trailing edge of the wing.

I had settled on running the wing at 16 deg at Buttonwillow in the 13CW configuration (~75 mph average speed, fast corners at ~90 to 95 mph, with a lap time of 2:09). That track configuration has relatively short straights with low top speeds (a little over 100 mph) compared to Auto Club Speedway where I reach 130+.

I was running it with that configuration at Auto Club Speedway too but that track only has one high speed turn and it's the very high speed banked oval, so I think I can run a lot less angle there (or none) for better lap times.