Has anyone use a leaf blow for tuft testing
 

Just thought of this on the way out the door. Using a leaf blower for tuft testing of specific aero mods. What are you thoughts.

Nice thought, but it could produce invalid results. The biggest problem is, airflow across one part of the car will influence flow across other parts. You'd need a blower big enough to move air across the entire car, and for at least a few feet to either side.

Another problem is speed. You need the air to go fast enough to transition from laminar to turbulent at the same point on the car. I've heard you should test at >30mph.

And if you want to test things that are near the ground, you want the ground to be moving and the wheels to be turning.

A good leaf blower will blow at 200 MPH out of the hose.

That's definitely an interesting thought.

Interesting thought, but I think I agree with Mr. Smalls. Would be interesting to tuft test in the normal way and then see how the result differ using a leaf blower.

How about borrowing an industrial sized blower, they move lots of air. There are rental places that rent them out here for about $25 per day. Be warned they may take pickup to move them, Should be able have a wide enough air flow to test the whole car.

... Or test with a smaller version of the planned mod... like 1/8 scale...

Cheap and easy is a coast down test and a friend with a video camera. See the chapter on wind tunnels in "Race Car Aerodynamics: Designing for Speed" by Joseph Katz.

That's a good idea, and would be pretty easily modeled for me with the square-ish design of the vehicle I'm working on.

I actually tried it one day, the results weren't anything like what the tufts did in actual use so I'd say it doesn't work.