Aerodynamics of a bug

[Jadewombat]

Did some testing with the car just a little while ago. No one could help me film the outside of the car so I just stuck my arm out the window to video the left front part of the car. This is all in anticipation of drilling some holes along the back of the fender. So, thoughts?






Where should I drill the holes, would it help aero flow or not matter? This racer from a few pages ago has holes along the bottom back of the front fenders. I also plan on running some fender flares to match the fender edge with the tires better.

[Wally]

Great testing! Kudo's to you!

I would make some vertical slots in the front fenders as near to the body as possible. Might do some to mine.
The overpressure on the inside of the fenders will not show with the wool on the outside though. Still, you'd think that the flared fenders will grab more air then original ones.
For some reason my car seems to have huge drag at speed. Part might be the air grabbing fenders (and wide tires) is my reasoning.

[Gerrelt]

Nice test work Jadewombat!

Like Wally said, you're talking about two different things. Your tests show how the aiflow is over the fender.
The slots in de fenders are for relieving air "pressure" in the wheel wells.

BTW, the airflow shouldn't be attached all the way to the bottom of the fender. Turbulence behind the fender is good, that means the airflow is de-attached from the fender. The angle of the rear of the fender is too steap for good airflow.

I think you could improve the aerodynamics of your beetle by installing wheels that fall inside the fender. Or install wider fenders. Your wheels stick out a couple of cm's, that can't be good for aerodynamics.

Again, nice work on the wool tuft test! I hope more people do this!