Ecomodding an automatic '04 Civic Sedan

[California98Civic]

Originally Posted by mpg_numbers_guy

Have you tried using black caulk to seal the gap?

I have thought of that, but my preference was to inset maybe a long strip of black coroplast that would also compress by not stick. Maybe I could use the coroplast and "face it" with a bead of black caulk, first dressing the trim pieces with linseed oil to prevent adhesion to anything other than the coroplast. Hmmm....

I should just try it already! Car is officially off the road again for a couple days so I can tear down the engine to replace the head gasket. But I need my car, so I gotta do this quickly. One problem for me with "black and green" is that it needs work often enough that and I end up using what "car time" I can get on repair and maintenance (learning, prep, execution).

I love this old car. Your pics from Bonneville above make me miss the place. I was there for World of Speed in 2012 with my daughter. I taught her to drive on that salt. She was 10. Good times.

[Vman455]

Originally Posted by Xist

We try to make cars more aerodynamic, but race cars regularly sacrifice CD for downforce and other concerns that are not ours. Honestly, I do not know what good either of those spoilers would do, but I found a picture of the front of that second Civic, The World's Fastest Civic:



They fastened those bands across the roof?

Have you ever used the aerodynamic template tool for your car? My spoiler is a couple of inches high, but still several inches under the template, so it probably does not affect airflow at all. If you made a rear wing that extended past your bumper, you should be able to reattach airflow. Good luck!

There have been some discussions of the double spoilers of the Merkur Xr4ti, but that still does not approach the template.

It's important to keep in mind that the template is an idealized form; it isn't the only way to do things, and most real-world, low-drag cars do not adhere to it. Aerodynamics are too complex to distill into a single shape and say that's the only way to do it.

Example: the GM EV1 is drastically sub-template, yet achieved a very low Cd. And, with a tail extension that was also sub-template, set a land speed record for electric cars with an estimated Cd .15.





Similarly, the Merkur XR4/Ford Sierra formed the basis for Ford's Probe III, which didn't change the body shape or double-decker spoiler. It achieved Cd .23:



Typically, Bonneville cars are set up for low drag above downforce, as most of them are ballasted and quite heavy.

The strips on the backlight and roof are probably for lateral stability, as are the spoiler endplates.

[elhigh]

I don't want to talk too much about my grid charger and its consumption when it's kind of off thread, but just to put it to rest it consumes about 100w at full power.

I like the front air dam. I'm seconding the other guys that mentioned adding washers to spread the stress over a wider area.

[mpg_numbers_guy]

Originally Posted by California98Civic

I have thought of that, but my preference was to inset maybe a long strip of black coroplast that would also compress by not stick. Maybe I could use the coroplast and "face it" with a bead of black caulk, first dressing the trim pieces with linseed oil to prevent adhesion to anything other than the coroplast. Hmmm....

Aren't some caulks relatively easy to just peel off? Can't imagine it doing anything to your car.

Originally Posted by Vman455

It's important to keep in mind that the template is an idealized form; it isn't the only way to do things, and most real-world, low-drag cars do not adhere to it. Aerodynamics are too complex to distill into a single shape and say that's the only way to do it.

Example: the GM EV1 is drastically sub-template, yet achieved a very low Cd. And, with a tail extension that was also sub-template, set a land speed record for electric cars with an estimated Cd .15.

...

Similarly, the Merkur XR4/Ford Sierra formed the basis for Ford's Probe III, which didn't change the body shape or double-decker spoiler. It achieved Cd .23:

Testing would be the only way to go...but testing requires fuel and will ruin my tank average. xP

Originally Posted by elhigh

I like the front air dam. I'm seconding the other guys that mentioned adding washers to spread the stress over a wider area.

The self tapping screws we used had washers that came with them.

[mpg_numbers_guy]

Update on the air dam! HUGE difference! I can actually see the numbers being higher more than my other mods! With my other mods I had to test them to get any idea of their benefit (other than noticing how they helped coasting), but this air dam is amazing! Whoever said that it is the single most helpful mod next to a boattail is right....I set my new short trip record today of 47.1 MPG (excluding the 47.89 MPG I got over a series of 4 longer, 30 mile trips). I tested it compared to my baseline yesterday (weather is literally the same), and got a 1.2 MPG improvement with the air dam, even with a slight breeze against me today with the air dam on. With my tank average of 40 mpg this results in a 3% improvement in fuel economy. Testing isn't perfect ABA, and honestly it feels like a whole lot higher; my Torque numbers have been crazy high since installing it.

It's a winner! It's definitely my favorite mod to date, not only due to it being relatively low profile compared to my other mods, but for it's hugely noticeable increase in FE. It's worth as much as my grille blocking and wheel covers combined on trips over 6 miles (grille blocking's effect is more noticeable percentage-wise over my shorter 5-6 mile trips).

DO IT! Get an air dam on your car. I swear I've never been so excited over a mod before.

[elhigh]

NICE. That's going to pay for itself really fast, too.

[mpg_numbers_guy]

Originally Posted by elhigh

NICE. That's going to pay for itself really fast, too.

Air Dam ROI:

$4.97 (lawn edging)
+$6.49 (self tapping screws)
---------
$11.46 (subtotal)
---------
$12.15 (after tax)
/ $0.08/gal (3% @ ~$2.67/gal)
---------
~152 miles to break even, then all free gain (quarter way there so far).


Wheel covers + grille blocking ROI:

$6.99 (duct tape)
---------
$7.41 (after tax)
/ $0.09/gal (3.3% @ ~$2.67/gal)
---------
~82 miles to break even, then all free gain (halfway there so far).


Inflating tires from 32 psi to 41 psi ROI:

$1.00 (air compressor was broken so had to pay for air)
/ $0.09/gal (3.6% @~2.67/gal)
---------
~11 miles to break even, then all free gain (passed a long time ago)

[teoman]

Are those thousands of miles? Or is that the decimal dot. Rounding the numbers would make them clearer in this situation.

Congrats!

[mpg_numbers_guy]

Originally Posted by teoman

Are those thousands of miles? Or is that the decimal dot. Rounding the numbers would make them clearer in this situation.

Congrats!

Those were decimals. Edited, ty.

[California98Civic]

Originally Posted by mpg_numbers_guy

Aren't some caulks relatively easy to just peel off? Can't imagine it doing anything to your car. ...

Maybe only the kind I have used have adhesive qualities. I can look some more. But it is not damage to the car, but ripping of the caulk if I have to remove the side skirts for any reason. The black caulk I used around the headlights ripped in ugly ways when I took the fixtures out to service them.