Cerox
 

This is the beginning of my fuel saver crx modification.

I have an 88 crx si that a previous owner had swapped a 2000 civic d16y8 into.

It's been setup for autocross and beaten for some time until I purchased to run up the freeway 1.5 hour round trip daily.

So far, I've cut the bottom half of a 95? civic front bumper to make a front "lip" aka air dam to you and I.

Today I just finished my rough first edition of a partial kamm back.
http://s30.postimg.org/pcgey588x/20150117_141941.jpg

http://s30.postimg.org/l75ic8agx/20150117_141947.jpg

http://s30.postimg.org/suseuj94x/20150117_141956.jpg

http://s30.postimg.org/6mofhefi9/20150117_142010.jpg

http://s30.postimg.org/gvgwn83k1/20150117_150016.jpg


upload a gif

Kamm-back
 

You won't need much vertical modification.You could almost go straight to boat-tailing.
http://i1271.photobucket.com/albums/...itled9-1-1.jpg

I effectively extended the rear eleven inches. I would really like to do a belly pan before a full boat tail but we'll see. My partial kamm turned out like a drag spoiler, not sure if that's a good or bad thing. Thanks for the photo, is that where the optimal template covers?

spoiler/template
 

*The base pressure of the wake is governed by the pressure at the line of separation.If only one face of the body is elongated,the wake pressure will still be the same.
The only way to really get the drag down is too do a complete box cavity or boat tail.
Here's my '84.She was estimated at Cd 0.235 from top speed and MPG
http://i1271.photobucket.com/albums/...itled310-1.jpg
http://i1271.photobucket.com/albums/...ead2/205-1.jpg

Seems to me as if the first gen's roof is higher in the front, more dramatically than the second gens.. maybe it's just me.

The idea in my head is to raise the muffler up as I've seen done on honda tech in a thread started by vectorsolid.

I will at that point build a diffuser to Finish the belly pan at this point, the ideal boat tail length should be a lot shorter, right?


Aerohead, I saw a photo of your toyota with what seems to be a cowl induction hood. Can you explain or link me to some details on that? NVM http://ecomodder.com/forum/showthrea...-28791-20.html

That could in my mind help with drag created by wipers, which I'm not at all ready to lose for the rain gets pretty bad here in the sunshine state.

Also, at the autocross, they told me to look ahead.. included some verbiage about taping the windshield and or helmet visor?..

I have some pre-fit side skirts available. They are three inches tall and the bottom flares out 1.25 inch.

Can anyone tell me if this is a worthwhile modification?

I was thinking combined with the air dam in the front I should lose some road noise and possibly make the car a little more slippery?

If I do this, when bellypan time comes, would it be better to match the pan to the bottom of these and the air dam?

I've also been toying with ideas involving replacing the entire hatch with plexi, making the hatch easily removable and side window visors.

I used to have a 1994 4 dr s10 blazer which I would on highway trips remove the rear window. It seemed to get better econ since all the other windows were down(no ac) and without the rear window, there wasn't a paper tornado in the cabin.

Does anyone have experience with removing the hatch on a crx? I tried to space the latch mech with 2 large chain links and all that did was re-route exhaust through the gap.

Thanks to all in advance.

What would be the final road clearance? Consider the https://search.yahoo.com/yhs/search?p=breakover+angle.

also speed bumps:

I've seen it suggested that the closed and latched hatch contributes to the stiffness of the body. You might need some internal gusseting added.

The CRX already IS a Kammback. Extending a Kamm is boat-tailing.

OP -- I applaud your initiative. Now back to the regulars' bickering:

Bonneville spoiler ——> box cavity ——> boattail

http://ecomodder.com/forum/member-fr...ture5476-9.jpg

Freebeard, what's in the photo? is that a box cavity?
NVM I found the anal probe thread with a box cavity.
The photo must be a Bonneville spoiler.

My partial boattail doesn't move at 70 mph so even if it's not doing anything for aero, I doubt it's doing anything negative so it stays for now at least.

I do need to do something with the muffler, it's 2 inches below the lowest point of the rest of the body.

I think I'm going to build a channel 3.5 inches up into the spare tire hump so I can raise the muffler 3" or so. that should give me some room to start on a diffuser. dependent on where the muffler ends up, I may cut the rear bumper to get the diffuser up to a good angle.

Any input for a diffuser that will keep my car usable at 120mph ish (assumed top speed) for when I get it onto a track (sebring is less than an hour away) and not too detrimental to aero efficiency?