mothernature's kammback... - Fuel Economy, Hypermiling, EcoModding News and Forum

malibuguy · 03-03-2009, 08:51 AM

this is pure snow & wind...i did not touch it...now i need to make it!!

i think its perfect

Nevyn · 03-03-2009, 09:23 AM

I guess that tells you the optimal angle for your hatch!

cfg83 · 03-03-2009, 11:57 AM

malibuguy -

Oh my goodness, that's so cool! But, I would suggest a different material than snow,

.

CarloSW2

Matt Herring · 03-03-2009, 12:26 PM

After the 8 inches of snow we got on Sunday night/Monday morning I had a built-in grill block on the front of my 4runner. Gently wiped off the headlights but left the ice/snow pack intact on the grill. 15-20 degree temps the last two days and it's still there! Of course, the frigid temps made my mpg plummet on the SGII for my commute but I figured the snow/ice grill block can't be hurting FE so I left it.

MetroMPG · 03-03-2009, 01:54 PM

Great photos!

Quick! Get some fiberglass mat & resin on there before your mould melts!!

I guessed from the title that's what I was going to see when I opened the thread. Seems like each winter someone posts a similar pic. (Not complaining - it's still interesting!)

If I'd had my camera a couple months back, I would have taken a similar one of a snowbound Jetta to post in trebuchet's CFD analysis Kammback thread.

wyatt · 03-03-2009, 02:13 PM

When I was in Wisconsin over the holidays we had this happen to my wife's car. I had to drive it into town so I left it hoping it would help my FE. As soon as I hit about 30 mph it started to get worn. I watched how it was picked apart as I drove down the highway. the sides went first until about 3/4 gone, then the rest went in one fell swoop. I figured that it means that there is a lot of turbulence coming off the sides of her car (and probably other sedans also) but not much over the top since that seemed unaffected.

MetroMPG · 03-03-2009, 02:43 PM

Quote:

Originally Posted by wyatt

I figured that it means that there is a lot of turbulence coming off the sides of her car (and probably other sedans also) but not much over the top since that seemed unaffected.

Probably right. I noted turbulence on the sides at the rear of my car when I tuft tested the Kardboard Kammback. I assumed it was caused by the side mirror; folding it in reduced the apparent turbulence.

You can see it starting around the 2:00 mark:

http://www.youtube.com/watch?v=j6ViIo76cCc

malibuguy · 03-03-2009, 04:29 PM

metro, great video...really makes me reconsider driving with the windows down in the summer now

my question is, if i were to make the kammback...how would i make this without interfering with the trunk operation...?

i was thinking of some kind of hindge'd thing that like "clipped" onto the rear spoiler or something...i dunno, but this snow kammback has really got me thinking that this could really help out...& maybe even on the road course...with limited HP (92 stock

) i could use all the straight-line speed i could get...plus potentially added stability

cfg83 · 03-03-2009, 04:49 PM

malibuguy -

The angle is wrong on this picture (I did this before I understood the need for an angle), but the "idea for attachement" is relevant to what you are thinking. It is by no means "the" solution, but it may kick-start a better solution by you :

CarloSW2

.

Christ · 03-03-2009, 04:52 PM

I actually suggest this kind of "natural prototyping" for aero modding all the time.. it always seems to "get the grade" if you will.