Aeromodded Civic VX 72mpg (image heavy)

[ecoTex]

Dang, Pop! Almost at 85mpg! Your next fill-up should show your worst tank falling off too! How is the CRX coming? We are dying from anticipation.

[The donkey CRX]

Hi ecoTex, I have still been "extreme hypermiling" while I have almost perfect weather. As you can see by the closeness of the results on the last few tanks, it looks like I have "hit the wall" as far as my hypermiling skills and the potential of the RED MULE in it's current configuration.

My goal was 85 mpg for the 90 day average and 80 for the current lifetime average, and I may just make it before the weather changes.

As far as the CRX, nothing exciting yet. This week I have been rebuilding the brakes and searching for the source of the anti-freeze smell inside. Probably a leaking heater core.

I want to get the CRX in good mechanical shape before all the fun starts with the aero package.

[j12piprius]

The donkey CRX, may I ask what method you used to attach the front air gap strips, and the front and top of the back wheel skirts? Did you use plexiglass and aluminum for the entire back wraparound boattail, and are the back wheel skirts made of aluminum? Thanks much for your inspiration and helpfulness.

[The donkey CRX]

Hi John, Both the front air gaps and the rear fender skirts were attached by cutting 1" by 1" 90 degree angle aluminum into 1 1/2" lengths and using #6 X 1/2" stainless screws to attach it to the lip of the fenders.




Then I attached a 6-32 stainless bolt with a 6-32 nylock nut to the angled aluminum. the angle was recessed back into the fender lip enough to move the nut back so when the air gap or rear fender skirt was installed with another nylock nut on the outside it would be flush with the fender.







The back boat tail was made of the following materials.

The Kammback part is made from 24 gauge (0.0250 inch) aluminum sheet. The top of the Kammback was a commercially produced "drag racer wing" that was scrapped by someone else in the shop and I don't know were it came from. Here is a picture of one on Xntra's VX with out my added side "wings".



Here is the best picture I have of where I added the side "wings" to get the boattail extended down to just above the taillights.





The bottom of the boat tail (diffuser) is made from 10 mm coraplas, the same as the belly pan so the transition between the two would be smooth.



All the other parts of the boat tail and fender skirts other than the lexan tail light section was made from the 24 gauge aluminum sheet. All this sheet was either scrap or damaged material, so I don't know how much this stuff costs (I was afraid to ask!)

Here are some more detail pictures that may give you some ideas on how to attach some of the items together.

[vrmouseyd15b]

Respect! Looks great!

[j12piprius]

Originally Posted by The donkey CRX

Hi John, Both the front air gaps and the rear fender skirts were attached by cutting 1" by 1" 90 degree angle aluminum into 1 1/2" lengths and using #6 X 1/2" stainless screws to attach it to the lip of the fenders.

Thank you very much for the details!

Then I attached a 6-32 stainless bolt with a 6-32 nylock nut to the angled aluminum. the angle was recessed back into the fender lip enough to move the nut back so when the air gap or rear fender skirt was installed with another nylock nut on the outside it would be flush with the fender.

Do you mean like this?
bolt on inside > aluminum fastener > nylock nut in middle > aluminum skirt > nut on outside
Why not have a more aerodynamic screw head on the outside, or do you feel there's not much difference aero wise, and having the nut there makes removal much easier? How often do you remove the skirt for checking your tires?



Also, what did you use for the side skirts, and how high are they from the ground, 5 inches?

Best regards.

[The donkey CRX]

The answer is yes to what you said above. It is much easier to match up the holes in the skirt to the 6-32 "studs" on the aluminum angles than trying to find threads in the angle with a bolt on the outside and I don't think I'm losing much aero with these small nylock nuts, but it would look much sleeker with button head bolt heads on the outside.

Also I forgot to mention that almost all the 6-32 captured bolts (studs) are different lengths depending on which part of the skirt they are holding flush. the ones in the very lower and forward part of the skirt being the longest (1 1/2") and the shortest on the top back (1/2"). Fortunately I had a variety of lengths at the start.

I don't have to remove the skirt to check the tires. I just jack up the rear end and they droop down enough to air up or inspect. I would need to remove the skirt to change the tire.

The side skirts are 6 inches wide and are made from the regular thickness coraplas. They clear the ground by 5 inches and I have never heard them scrape.

[j12piprius]

The donkey CRX. thanks much for the helpful information.

I'm planning to make half back wheel skirts, to avoid any bulge in the bottom. Maybe I can silicone T nuts through the fasteners, that will stick into the skirts, then use T bolts from the front.

[j12piprius]

The donkey CRX, the front fenders on my car have a rubber material attached to them instead of metal lips. It looks like attaching strips will be difficult.

Can you tell me how long the lip is on your boattail and how you decided on the length? I'm guessing 3 to 4 inches. I'm thinking to start with a piece of aluminum on the top of my trunk and then go from there. Did you fold back the end to get rid of sharp edges?

[The donkey CRX]

Yes, the lip on the very back edge of both the Kammback and diffuser is about 3 inches wide with a slight 1 1/2" wide up angle on the Kammback and down angle on the diffuser. I tried to copy the shape from the back of the Chevy Volt.

The "folded back edge" is actually a small U-shaped vinyl piece normally used on the edge of car doors to keep from damaging the paint if you open the door into something. It came in a roll from Auto Zone.