Howdy,
I'm bumping my
cleanmpg.com post here as it seems to be a better place...
Sorry: Photos don't swow up in here because my URL is mangled by the swear word detector. Click above likn to see them
Ideas and comments on how to tackle the underbody project and with what material are welcome.
Kitcar: Kudos for the videos, but when you can, do include the test results @#!$. You make me hoping I can reach 30MPG @75MPH
I am nw wondering about trying a front lip (air dam) for the CR-V. Maybe a flexible plastic, foam or vinyl might work (sitll wanna get some off-road capability). That would be good at least for the wheels.
I might also try to apply vortex generators to create air bubbles in the complext parts.
My original post w/o photos:
Anybody around with some aerodynamics understanding to help me out?
I took some photos of my 2002 (Gen'2) Honda CR-V. I think there's room for improvments by covering it... Maybe get some noticeable MPG out of that.
For info, this SUV is meant for long highway drives, followed by light off-roading (not necessarilly well maintained forest dirtroads or paved with potholes, or the likes). I did not meant to buy it for city driving, nor for heavy off roading though I can't exclude to ever have to do with it a little approach drive through rocks or cross rivers...
BTW, if I do tuft testing, what speed is needed? I'd have to attach a camera somehow at different spots.
Pic 1:
On the right, we can see the gas tank sticking out protected by a tubing, and in front 2 parallel frame beams.
The muffler and drive shaft (also protected by a V-shaped bent metal rod) probably get very hot so can't be covered much.
The rear wheels are not covered, partly because of clearance I suspect. Note that the clearance is excelent: There's lots of room in the middle so this SUV could pass pretty big rocks with proper driving, to pass them by rolling on top of the high points.
Pic 2:
There we can see the bottom of the bumper and the cladding under the engine. I assume that part protects from dust but also evens the flow of air going into the engine for proper cooling.
Notes:
- The cladding is not uniform, and could be smoothed out.
- There's no lip to create a depression or push air to the side.
- There's no lip in front of the tires to reduce wheel drag and car stability (though it's pretty stable passing trucks).
Pic 3:
A close-up of the gas tank and rear. Note: If I create a sloping underbody cover here, I feel like adding room for a portable gas jug in front.
Adding a cover has the added benefit of protecting the brake lines from debris.
Pic 4/5:
The rear passenger side... Not much to do except maybe cover from the rear suspension to the back. I'd have to see what parts are moving with the suspension. The shiny part seems to be a heat shield for the spare wheel well.
Pic 6:
Front wheel well passenger side.
The wheel is totally exposed to wind as well as the hole where the wishbone moves. The space is open with the engine bay and wheel well. A big fat lip might help there, or a vortex to create a bypass bubble around the hole without creating too much turbulence.
Pic 7/8:
Rear driver side (and passenger side) wheel shooting from the back of the truck.
Definitively some flattening would help the flow there. The trick is doing that with the large moving suspension frame. I don't have any ideas except maybe using some kind of flexible rugged fabric. Again I don't know what are the cooling characteristics that need to be preserved.
Pic 9/10/11:
Some details of the body aerodynamics
The wipers are not well protected it seems.
The rearview mirror is kinda flat, and the pilar holding it kinda big, must create drag.
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