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Old 04-23-2021, 10:34 AM   #47 (permalink)
Vekke
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Quote:
Originally Posted by JulianEdgar View Post
Yes even the first Honda Insight 20 years ago had shaped front tyre deflectors. Not to mention the Ford Probe IV concept car. My points are that (1) I have never seen any publication that suggests that flat plate deflectors are fitted because of potential kerb impact, and (2) I cannot see how such a tiny change will be measurable outside of a wind tunnel. I had hoped we’d gone beyond the ‘guess and rule of thumb’ approach to aero modification here.
https://publications.lib.chalmers.se...512/250512.pdf

Here is a cfd study on spats. lower is better for wheel drag but whole car drag starts to rise after 40mm flap heigth in this test. I measured roughly the ground clearance in that model is 150mm and tire width 210mm (205 or 215). They tested only flat spats. That 40mm flap leaves 110mm ground clearance and that 60mm flap leaves 90mm ground clearance.

Max savings in that cdf study just on front flaps was 5,5% on drag. I believe that is easily measurable on road.

If you are able to get those lower flaps working that lower wheel drag 18,8%, without increasing too much body drag more is possible than that 5,5%. And this was just for front spats. So different shapes and sizes will give different results.
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