Aero Mods Opinions Needed
 

I am new to ecomodding and hypermiling but I'm catching the bug fast. I recently started keeping a fuel log for my 97 Honda Civic EX. I first set a baseline by driving several tanks with no modifications to my driving style or to the car itself. I have since then moved on to just adjusting my driving style. I am on the first tank of that phase but I can already see a drastic improvement just by watching my fuel gauge and odometer.

My end goal is to drive efficiently (and safely) and to improve the aerodynamics of my vehicle to assist in the endeavor. I do not plan on making drastic changes (boat tail, etc) but I am interested in some smaller modifications (wheel skirts, air dam, wheel covers, less side mirrors, etc).

My question concerns the air dam. How much airflow should be needed over the radiator to keep me from overheating? I live in Houston Texas so it gets pretty hot during most of the year and I would rather sacrifice a little fuel to keep from burning something up but I hear that the factory grills are usually excessive.

I work in a model making shop and have access to every kind of fabrication process imaginable (sheet metal working, machining, auto paint, acrylics, fiberglass, laser cutter, welding, and even a rapid prototype machine) so I think I could come up with a completely new front end for my car.

Any ideas/opinions would be greatly appreciated!

probably best to just experiment. I'm finding with my grill block that there's a lot of other stuff (besides the size of the hole) that affects the amount of air that goes through the radiator. Hopefully someone else will chime in - you should check out Andrew's 70 mpg white civic - Improving aerodynamics of 5th gen civic hatchback.

I think that's where I was headed as well. I thought of just putting a temporary grill block on to see what kind of temperatures I got. From there, I can increase or decrease the opening until I find a sweet spot and transfer that to a more permanent front end. I think I'll use the NASCAR method: tape. :p

I set my baseline MPG at 31 with a little bit of testing. I ran two tanks like I normally would: traveling ~70 mph and never coasting or turning the car off. I also just completed my first tank with improved driving habits and I am proud to say that with no alterations to the car (and having to drive about 40 miles with an extra 700 lbs at one point) I made it to 37.6 MPG! I think with a little practice and refinement I can get it above 40 before I even start modifying my car's aerodynamics.

I'm going to be doing a grill block first. But before I can let myself start taping the front of my car, I want to know how much it improves from the modification. So, I plan on running through at least three tanks with me driving very efficiently so I can find a normal point for my car. Then, I'll tape off the front of it. I don't imagine just a grill block will increase my FE a ton but I want to experiment with the airflow through the radiator and see how big the opening needs to be so I don't overheat the engine.

That's as rational a plan as you could have.'Don't want to cook the beast!

I tend to be very rational. To a fault maybe lol.

I did reach 40 mpg before modding the car at all for those who care to know. my last tank was 40.23 mpg. Made my day :D

You'd be surprised how far you will get on driver adjustment alone ... I made my goals with that alone, now because of my competitive nature, I want a slicked out, fully modified, what the hell kinda car is that ride that can do the speed limit and get over 60mpg.

So approach it with a good attitude and have fun, that way you can laugh off the dissapointing hick ups ...