5th generation civic hatchback - improving aerodynamics

[LostCause]

That is amazing.

Everyone that joins the forum should get a packet outlining the mods to your car. Want to raise your mileage? Be like AndrewJ...

Originally Posted by Funny

You car is starting to look like it's from Back to the Future .

No kidding. I wouldn't be surprised to find a Mr. Fusion popping up on his dash shortly...

- LostCause

[Wayneburg]

I love your ingenuity! What you are doing if very inspiring. I plan to mod my next car with some of the same ideas and a few of my own. I'll have to take pics of my progress like you've done. So much to do now...

[2003protege]

dude, that is so awesome!!! I gotta say, that I love the attention ecomodder pays to aerodynamics. Congratulations on the latest mileage and the car is looking awesome!

[Cd]

Originally Posted by AndrewJ

I'm literally about to dash out the door to go to the MPG rally, but I just filled up the tank and got....



68.52 mpg!!!

Holy crap!

Can you remind us of your MPG rating before you started to do the aerodynamic modifications ?

Also, how many miles per gallon would a person get if they had a car identical to yours ( with just the aero mods ) but drove " normally " ( meaning driving at least 70 MPH with no "cheating" such as engine off coasting ... etc.

For example, let say driving on the highway at 70 MPH ( but with the with the A/C off . )

How many miles per gallon did you gain from using the alternator kill switch ?

I could go back and find all of this info. in the prior posts, but I thought it might be helpful tio have it all in one reply for any new viewers that skip to the end.

Thanks for the inspiration Andrew !

[JV-Tuga]

Originally Posted by .Cd

I've begun looking for a small / cheap web cam that I can mount to the outside of the car. ( for tuft testing )

Check this out: http://www.4kam.com/

And this is How I came across that camera, Sven is a pretty cool guy: Sven's Video Page, which includes a description of his current setup

I hope that helps someone. It doesn't seem to be expensive to me. The setup seems pretty well priced as far as bang for your buck. If it is too much for anyone individually I'm sure there are enough of you guys around here that can buy it as a group and share.

I also found a camera system that is good enough for a proper mirror delete. I'll post about it in a more relevant thread (done, you can find it here). The only possible drawbacks are: price, weight and power consumption for you non-alternator fiends. Since I feel that I am not qualified it will be up to you to decide if the benefits outweigh the drawbacks.

BTW, I am new here and this is my first post so...Hello world...of Ecomodder.

[AndrewJ]

So I re-did the grille opening today.

It was already "appropriately" sized according to the NASCAR rule of 4 square inches of grille opening per 25 horsepower.
My old grille opening was 12 square inches, and it was plenty, as long as I wasn't running beltless.

The main problem was that the radiator fan would still kick on a bit, consuming a bit of battery power every time it did so. So for running a beltless alternator, more grille opening (to reduce or eliminate running of the radiator fan) is desirable.

I increased the opening to about 4" by 4" or 16 square inches.

I also replaced the manual choke cable with some 1.5mm steel cable inside bicycle cable housing. The manual choke cable was just too stiff to make the several bends on the way from the dashboard to the airdam. (it was after all one solid strand of wire)









And here's the guts of the new grille opening, it slides horizontally in two rails, and there's a spring to help it return to the fully closed position.


And I had to replace my killswitch, I've apparently been using it a bit too much as it wore out and became very hard to switch. So a new one was in order.

I was pretty proud of myself for wearing it out

[Daox]

Looking good Andrew!

How often do you find yourself altering your blocks position?

[MetroMPG]

Nice to see the car getting more refined.

[reformed]

I see a small fault with the NASCAR logic, in my eyes at least. Maybe you can show me I'm wrong here as I didn't look this up, but I'm assuming that the NASCAR rule for 4 square inches per 25 hp is probably taking into consideration that their average rate of speed is much greater than yours, so they squeeze in more air per those square inches than you do. Then again they are making upwards of 800hp IIRC, and you're making 100hp give or take, so this may be a null point.

[Otto]

I dunno about the NASCAR 4 square inch rule, but NACA did considerable cooling duct work in the 1940s, indicating that diffuser inlet ducts are essential, as well as proper outlet ducts that smoothly rejoin the cooling air with the slipstream.

Probably, a round or elliptical inlet at the stagnation point, with radiused edge and diffuser duct that grows in diameter to 2 or 3 times the inlet size, coupled with a constricting outlet duct that rejoins the slipstream in almost parallel flow, would be best.