Partial Boattail/Kammback on a sedan?

[freebeard]

Pix pleez.

Once it's all secured with tape, four coats of Plastidip. I'm sure there's a combination like Pearlizer over Real Aluminum that would closely match your paint.

Cutting concave curves on the sides and convex across the top is the modern style.

[19bonestock88]

So I’ve noticed my Kamm lifting as I drive... as speed increases, the trailing edge rises... I still think I have more drag than without the visor/Kamm... in the rain the water seems to be moving almost horizontally across the backlight...

[19bonestock88]

So I took off my Kamm for revision and am driving the car without it while it’s being reworked(slot in front and better edge reinforcement)... as it was, it seems to have been costing me a few percent... instant MPG with the visor/Kamm on was around 31@43-45% load (remember this thing is running on three cylinders and in open loop) and with the Kamm off I can hold 55mph at around 38-40% load and about 36mpg instant...

I thought of cutting a whole new one a little longer(16”vs 14”) and positioning it a little lower on the glass(1.5” below the top of glass instead of st the top)... such a visor and position would yield the max length possible without interfering with the trunk lid...

[Ecky]

Fully warmed up, and with similar weather?

Aerodynamics is a bit of a black art.

[19bonestock88]

Car was at normal operating temp, and it was a little warmer/dryer when I was driving with the visor on the car(should have made its mileage better in comparison to my recent trip with the visor off)... temp difference wasn’t huge and the road moisture difference wasn’t too bad either...

[MetroMPG]

Tardy reply - apologies...

Originally Posted by mpg_numbers_guy

I know there have been myriads of threads related to kammbacks and boattails for hatchbacks, but how about sedans?

I "Kammbacked" my 2007 Civic so that I could later add a full tail and keep the "template" curve.



Unfortunately, the Kammback mod on its own (no tail) appeared to make NO difference in A-B testing:

I actually also compared Kamm alone (no tail) vs. bare car, and the Kammback appears to have made no difference. 49.2 mpg with it on, 49.2 mpg with it off, 8 runs total (each way).

Build thread: http://ecomodder.com/forum/showthrea...dan-31498.html

[Ecky]

@MetroMPG, what were your construction materials for that kamm?

[Vman455]

One snowstorm a few years back, this is the shape the wind came up with on a parked Civic:

[Ecky]

Some snow kamms I've seen locally:

[kach22i]

The old Snow Kamm Thread - I like that term Ecky.

http://ecomodder.com/forum/showthrea...ing-27509.html