Chin spoiler question

[RedDevil]

Second that. Air moving aside and over the car meets less resistance than under the car, especially if it would get squeezed there.

I want to upgrade the LGB on my '11 Insight to a bulge with a chin spoiler. The edges of the front bumper are set to 45 degrees sideways and form almost half the frontal area of the bumper, so the bulge should curve round for a flush transition. The lowest part of the edge planes protrudes by more than an inch, I want that feature on my bulge too; that would make a chin spoiler running from side to side.

But first the snow has to clear up, I have a garage but it is unheated and laden with other stuff.

[SlideWRX]

If there is already an aero pan to work with, I still think improving that versus adding an airdam would be more beneficial. The air underneath is only more turbulent because of all the stuff hanging down there that we don't address. If they have addressed that partly, finishing it off would be better.

Edit: well, they don't appear to have done much underbody; I expected more out of a new hybrid. Do the air dam.

[Recumpence]

My thoughts are to pick the low hanging fruit first. That would be doing a better grille block on all three (yes, count them, THREE) grilles. Then I will make nice heat shaped fog light covers (the fog lights are recessed into deep pockets), then the air dam. The chin spoiler will run back to the front axle area in a perfectly flat surface. Beyond that, I will address the rear area behind the rear wheels under the bumper. That area is totally open. Oh, I also figured out a slick method to transition the hood to the windshield. There is a big open area there that will be very easy to fill.

Ultimately, I like the kamback shape of the body as well as the sloped windshield. I am also happy that Ford addressed the under side of the car at least a little. But, it can be improved quite a bit. I have seen a 1.5 to 2mpg improvement by adding a grille block to the center grille of the car. I am hoping to see a total improvement of 5mpg through blocking all grille openings, adding the air dam with engine underpan, and the rear end under pan. But, who knows until all work is done. I am already at 45mpg lifetime mileage average, and that is mostly in very cold weather. In 50 degree or higher weather, I see 50mpg. It would be cool to see 55mpg through the warm weather.

Matt

[Varn]

One thing that is sometimes forgotten about modifying racing technology for the street is that the ground clearance can be minimized for racing but on the road, it is usually kept 4" or more.

A couple of personal data points are: I extended the front fairing on my VW so that it was about 2.5" off the ground (It drug the ground everywhere.) and saw no change economy for thousands of miles.

I built a racing trike fairing from zote foam that was just almost touching the ground and had an open bottom.

It worked pretty good allowing me to maintain 24 mph for a 100 miles on an open road race, I was pedaling. It was several mph above the speed that I could power it without the fairing. Of course the side effect was that the lower lip acted as a venturi and picked up buckets of sand off the road and I ended up with a black face.

Air does not like sharp changes in section. Unless the air flow is cut off nearly completely it doesn't seem to make much difference in drag. I think you would be better off with a lower radius extending to a belly pan.