Quick & Easy Kammback for Metro - Fuel Economy, Hypermiling, EcoModding News and Forum

T Durden · 02-05-2010, 10:04 AM

I bought some clear acrylic sheet and was going to fabricate some kind of Kammback following the guides here but then I got lazy. I just eyeballed it, drilled some holes and put in some rivets... The acrylic cracked a bit when riveting but hasn't gotten any worse since driving. Rust will undoubtedly form at the holes too... Works well enough for me but I don't know what effect it has on fuel economy yet.

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Piwoslaw · 02-05-2010, 11:20 AM

Hello T Durden and welcome to EcoModder

That is indeed a simple Kammie, and it appears you got the top angle on the dot at 13-14deg. I'm not sure about the sides, though. The inward angle seems quite steep which may effect the wake. I guess you're not willing to unrivet and rivet on the side of the road while A-B-A testing?

BTW: Those skirts look nice (the shape, not the rust). How long have you been using them? Are they easy to take off/put on?

cfg83 · 02-05-2010, 03:05 PM

T Durden -

Welcome to EM! I like it. I measured a 12.8 degree slope. Can you tell me the thickness of the acrylic? If I were you, I would seal any gaps that could allow air to sneak under the kammback. In the last picture, it *appears* that there could be a small hole where the acrylic slopes from the rear hatch "roof" to the rear hatch pillar.

CarloSW2

TomO · 02-05-2010, 03:31 PM

Welcome T Durden, don't start any fights in here

GAffers tape, or even Duct Tape (if you don't mind the residue) would be a quick and cheap way to seal up the edges of that kammback.

MetroMPG · 02-05-2010, 03:41 PM

I'm curious about those rear fender skirts too - is that corrosion from years of use on your car? Or did they go on that way?

thatguitarguy · 02-05-2010, 04:21 PM

Looks like a worthwhile experiment.

I like the skirts. Are they easy to remove? Looks like a good pattern.

Are those front caps rusted pizza pans, or just a rust colored material?

k.civic.f4i · 02-06-2010, 05:20 AM

im pretty sure its rust bro. rust sucks. nice skirts though

Johnny Mullet · 02-06-2010, 06:24 PM

Welcome to the forum.

T Durden · 02-07-2010, 10:21 AM

Thanks for the compliments on the skirts! They've been on the car for just a few months. I think I screwed up the painting, not cleaning them well enough before priming. They are easy to remove though, just a few "self tapping" screws holding them on.

The acrylic is about 1/8", 3mm thick. Yeah, doing A-B-A might be a little difficult, haha.
Yes, there are definitely some holes letting air under it, I'll tape 'em up!