Value of aerodynamics on small RC cars?

[carrunner]

I found a report that answers perfectly the question, see the link :
http://www.me.rochester.edu/courses/ME2 ... 6RCCar.pdf

title : Modifying an RC Car: Optimizing Down and Drag Forces
Author : ME 241 – Fluids Lab Professor Gans
Date : April 27th, 2011

This report did use some mesurable techniques to set a conclussion, so I think is worth it to add this to this post of 3 years old, yet the topic is still very interesting for me.
So in short, the conclusion from the report :

"These factors make the Full Body + Rear Wing + Diffuser the optimum available configuration."

(So be notice, that is without the underbody), although the aire inlet is not studied, I thinks it will still be helpful to make that.
Well, all depends what kind of speed and what kind of RC car it is, I assume aerodynamic do help some with high speed RC car.

[Greg Locock]

Don't the graphs in that report raise more questions than answers? Why does the downforce vary at 0 mph? etc

[carrunner]

Don't the graphs in that report raise more questions than answers? Why does the downforce vary at 0 mph? etc

Just take some time to read the report, that graph isn't that clear at first glance. To understand that, you need to know that, faster the car goes, more the car will be lifted. That's aero.

[bill shoe]

Don't the graphs in that report raise more questions than answers? Why does the downforce vary at 0 mph? etc

Good question. I think "downforce" in the report includes the weight force of the car. At 0 mph the baseline car is lightest, partial body is heavier, and full body is heaviest. So apparently the car was making net aero lift with increasing airflow speed, at least according to chart on bottom of p. 14?

Definitely unconventional way of showing the results.

[carrunner]

Don't the graphs in that report raise more questions than answers? Why does the downforce vary at 0 mph? etc

Good question. I think "downforce" in the report includes the weight force of the car. At 0 mph the baseline car is lightest, partial body is heavier, and full body is heaviest. So apparently the car was making net aero lift with increasing airflow speed, at least according to chart on bottom of p. 14?

Definitely unconventional way of showing the results.

That's true, I was also confused the first time I read that. They have done a good research but certainly not taken good use of those results. It is really a regret.
But at least we got something interesting, anyway, to do such experiment, equipments, time, money are required.

[Greg Locock]

I read it again and from what I could understand they /increased/ the lift on the car, and the drag, while increasing its weight. Can anyone interpret those graphs any other way?