Project: making a permanent Metro Kammback extension

[gascort]

Originally Posted by i_am_socket

The words "sheep" and "affair" should not be in the same sentence

My thoughts exactly!!! I like the sheet aluminum idea too; I would like to replace some of my aero mods with sheet metal after they prove their fuel savings. At $1/square foot, it's not too expensive, but it's more expensive than free coroplast.
I think with Darin's car, the fiberglass will look nice and is obviously the right way to do it, but I'm not skilled in fiberglass and don't have the balls to throw myself into it like he has. If someone else was helping me with experience, I'd go for it.
Will be interesting to see what his finished product comes out as.

[MetroMPG]

I'm not sure glass is the "right way" to do it. Andrew's plastic was definitely way easier, and it looks fine to my eyes. The only reason I wanted to use fiberglass was so I could use the foam base to get good compound curves on the sides/"shoulders" which I ended up not getting anyway when I abandoned the foam for cardboard.

That said, I got two layers of glass on the outside today.





Tomorrow I'm going to make a "form" to hold the shape of the trailing edge, then remove the Kammback from the car to resin & reinforce the inside.

After that, I'll come up with a mounting approach, and then start on the finishing work (bondo, sand, sand, sand, sand... Whoops - thanks for the bondo tip.)

[MetroMPG]

Random comments today from neighbours, passers by and the mail man:

"Making a batmobile?"

"Hey, looks like a CRX."

"Expanding your trunk space?"

"How will you be able to see what's behind you?"

[Peakster]

Looks amazing!

"How will you be able to see what's behind you?"

I don't know... How do moving trucks see behind them?

[2003protege]

Originally Posted by MetroMPG

After that, I'll come up with a mounting approach

yeah..what are you thinking for that? Is this going to be permanent as in bolted to the body/frame or removable with no remaining evidence of it having been attached? (permanent with respect to cardboard =P )

[lunarhighway]

looks great!

[cfg83]

MetroMPG -

Originally Posted by MetroMPG

Random comments today from neighbours, passers by and the mail man:

"Making a batmobile?"

"Hey, looks like a CRX."

"Expanding your trunk space?"

"How will you be able to see what's behind you?"

That's what I was thinking, but I know you are two steps ahead of the game on that one.

Looks fantastic! I have some ideas brewing, but they won't be nearly as nice as yours.

CarloSW2

[jwxr7]

Good work making it permanent . I'm still using the same coroplast and packing tape, retaping it a few times a year .

I should get a good side view shot of my car and compare it to the teardrop. My roof is too flat being a 5 door.

[C3Killer]

Nice, very nice!

[co_driver]

Originally Posted by .Cd

...
If you ever get around to running more tuft tests, I was wondering if I could request a favor : Both you and I have a rounded tail end to our cars.*
It would be interesting to see whether a 'trip stip' or a straight edge would have any effect on decreasing the vortexes.
I'd guess that they are rounded for a reason, but as we know, a sharp edge is usually better than a rounded end.
I meant to test this on my last failed attempt at tuft testing.

( * the tail light area )

One may have noticed on recent 5-series (I think) BMWs, that there are 'trip' edges at the sides of the taillights.

The trip edges do promote separation which will have less energy in the vorticies than those of a smoothly curved transition to a rear surface which allows an increased build-up of energy and stronger vortex.

Originally Posted by MetroMPG

Here's the un-edited tuft testing video for the hard-core aero fans:
... video ...

My sincere appreciation of your work/dedication is due ... If I had more time, time and time... (this 'work' thing gets in the way all too often!)