Decorative vents in front bumper?

[rjacob]

My Civic has decorative vents on either side of the lower grill. I think on other models, they might have lights there, I don't know. The only go in a little over an inch maybe.

Here is a Civic with a similar byumper to mine:


Would there be much if any benefit from covering those? I was planning to take a piece plexiglass, and cutting it to fits over the vent, overlapping the sides a little. I would paint it black and have it held in place by double back foam tape.

I was also thinking about extending the plastic piece in about 4-5 inches to overlap the sides of the lower grill to make a partial grill block.

Another idea I had was to make an auto bra that would cover the faux vents, and part of the lower grill.

Waddya think? Will it make a difference?

[socalsuperhero]

Originally Posted by rjacob

Waddya think? Will it make a difference?

slap some good old fashion duct tape on there for a few tanks and find out

[MetroMPG]

Likely not enough of a difference to show up at the gas pump. Which isn't to say it's not worth doing. All the little things add up.

[SVOboy]

I've heard they tend to form high pressure regions so they don't really make much difference in terms of aerodynamics.

[mwpiper]

Note the large number of decorative holes in the front of airplanes. (that's sarcasm, of course) Holes in the front of airplanes are either for cooling or breathing and making them too big can seriously affect performance.

A parachute has a higher drag coefficient than a flat plate which has a higher drag coefficient than a convex shape. A closed hole in the front of the car is a parachute. I also have non-foglight holes. They are currently taped over with shipping tape. I have big plans for reshaping the front of the car. None of those plans involve installilng forward facing decorative holes.

[rjacob]

I bought some plexiglass. I am going to cut it to shape, and try using a heat gun to soften and bend it to the curve of the bumper. I was planning to make it longer and have it extend out over the sides of the lower grill as a partial grill block. But I think I came up with a better idea. I was thinking of putting velcro strips long the top and bottom of the grill opening. Then I could cut some smaller pieces of the plexi to make a partial grill block that attaches using the velcro. Then in the winter months I could add pieces to block more of the grill.

[superchow]

Originally Posted by mwpiper

A parachute has a higher drag coefficient than a flat plate which has a higher drag coefficient than a convex shape. A closed hole in the front of the car is a parachute.

Never looked at it that way. Hm... now where's my duct tape?

[NeilBlanchard]

Hello,

I have small recesses with fog lights on my xA and covering them definitely was noticeable.

My theory is that the air flow is smoothed out, and it kicks out more cleanly, and goes around the front wheels? If you look at the front spoiler on (older?) NASCAR racers (pre-COT), they have a flare on the lower corners that does this -- they sometimes tried to "cheat" by increasing this.

[mwpiper]

Did you try to make plexiglass lens to put over them? I considered that for my Caravan, but; a) the foglights are very close to the edge of the bumper and the channel they are in help deflect air sideways so less wants to go underneath and, b) it's a freak'n minivan!

[rjacob]

I covered the fake vents. I used plexiglass. I cut the pieces to shape, then I heated them with a heat gun at the 1100 degree setting. When the plastic was soft and bendible, I placed each piece over the bumper to form the curves of the bumper. When the piece cooled enough, I set it aside to fully cool. Then I spray painted them semi-gloss black. I attached them to the bumper using double back foam tape.