Thread: Thank you
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Old 07-26-2021, 02:44 AM   #60 (permalink)
Isaac Zachary
High Altitude Hybrid
 
Join Date: Dec 2020
Location: Gunnison, CO
Posts: 2,075

Avalon - '13 Toyota Avalon HV
90 day: 40.45 mpg (US)

Prius - '06 Toyota Prius
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Quote:
Originally Posted by Vman455 View Post
Well, here's an example: I have my truck now, and the first thing I want to test is an airdam below the factory front valance. I could follow the (dubious) rule of thumb here that an airdam shouldn't extend below the lowest-hanging component under the truck, and based on that assumption build a permanent airdam and hope that it's the best design. Or...I could build a simple mock-up out of cheap coroplast and tape it to the valance, extend it all the way to the road, and use throttle-stop testing to measure the change in drag as I cut several inches off to test it at different heights and find the actual airdam height that reduces drag the most on my truck. Then I'll make a permanent airdam at the same height that I know is doing what I want it to because I measured it before I invested the time, effort, and money to build it.

"Optimal design" doesn't mean anything short of reshaping an entire car isn't worth doing.
That may work. I don't know. I have no experience with coroplast nor know where to even buy it. I've tried testing on the road, not necessarily by putting a stop under the throttle, but by holding a fixed MAP/load number on a screen and it's near impossible to get repeated results. Then comes to my mind the question of whether more effort would be better spent on figuring out if a straight up and down air dam is best or if it should come out at an angle or curve inward on the bottom, and if so, how much. And how much would I gain on a car that already has a bumper that extends down to a factory belly pan.
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