Front bumper aerodynamic testing
 

So after I installed my new bumper, I duct taped it with several layers of tape to see if it helped my gas mileage, and we all know what that does. I have the issue that I love the way the 200sx bumper looks, so I am going to see if blocking the back of the cutouts, instead of the front, renders the same result. I have several "calibrated hills" on my daily drive that I know what speeds should be when. I will post back soon. Here is my car with the mirror reduction and swapped grill and bumper.

So I noticed actually the same FE results whether the block was on the front face or recessed into the bumper. So after some work with coroplast and lawn edging, I have a final product (for the moment) that I would love to show if the stinking page would let me post it. I average with this setup a consistent 39.8 mpg. That is only a 1 mpg improvement, but still a noticeable improvement. The biggest gains have been in handling, both wet and dry, and coast down. It now takes twice the distance to slow down from 55 on level roads as it use to. I drove through torrential rain coming home today and it held to the road so incredibly well. I was even running the ac and didn't see as big of a drop in fuel consumption.

That's a 2.5% improvement from the grill block. That is about what most folks report, though the accuracy of most measurements is a bit dodgy.

That's a 2.5% improvement from the grill block. That is about what most folks report, though the accuracy of most measurements is a bit dodgy.

Inside or outside the grill work shouldn't make much difference. You are basically just shutting off the lossy flow through the radiator and engine compartment. The actual shape of the grill block makes little difference as the entire area is a high pressure point.

While a grille block can reduce aerodynamic drag to some extent, its main purpose is to provide a faster warm-up. That is where, IMO, most of the gain comes from.

I've been wondering if that is the case. I have a WAI and the car is at operating temps even during the coldest part of winter within 5 minutes of operation. I did notice an improvement of 4.5 mpg from no grill/bumper blocks to putting them in. I figure my mileage on tank to tank fillups.

How on earth do you add pics to these files without being too big?

upload first to photobucket or flickr
 

Okay, here are the pics of the front of my car.

http://i1255.photobucket.com/albums/...0220121656.jpg
http://i1255.photobucket.com/albums/...220121655a.jpg
http://i1255.photobucket.com/albums/...0220121655.jpg

The files were too large to link to the site.

What did you use for the bottom front lip?

Also photobucket or ecomodder should resize the image. When you are using photobucket image tab, just copy and paste.