[ACEL]

California98Civic - Your observation of the bumper cover is right for this test conducted in May 2020. (first picture attached is from the same series) I missed it. Thank you. There was little dust on the center of the bumper cover. The picture showing the dust on the corner of the bumper cover confirms that. Also, it seems that this dust pile up is directly related to the rear wheel located just ahead.

Second picture from a dust test today July, 2, shows that the situation is changed. Now, the dust piles up on the bumper cover center and much less behind the rear wheels. Modifications realized since the first "novice" dust test are the vortex generators, my take on the rear wheel boat tails, some side skirt deflectors just ahead of the rear wheels and the exhaust extension side oriented (assuming it energizes the air coming up from the diffuser into the wake).

Rear wheel both tails are made from the vinyl gutter leftover originally purchased for the side skirts (5,50 cdn$ for 10 feet length). Funny that I chose the open box design for these boat tails! Vortex generators at the center are the Amazon shark fin type, and the external ones are simple vinyl 90 degrees corner 3/4 x 4 inches while awaiting for more black shark fins ordered.

Green tapes on both sides show the actual locations of flow separation "read" from the dust deposition.

More on the mods later!

Thanks for your useful comments,

Regards,

Real (Acel)