Project: Geo Metro boat tail prototype - 15% MPG improvement @ 90 kph / 56 mph

[RobertSmalls]

Originally Posted by MetroMPG

I realize it's not very practical, in terms of hitting stuff. But wanted to go big or go home.

It won't interfere with approach or departure angles, since it's so close to the wheels. It won't be a problem in the snow, since the front dam should gently push snow aside, and the rear dam will ride in the wake of the tire. All you need is enough ground clearance for the biggest pothole you're ever going to hit, or the biggest curb you're ever going to drive up and over. I say make it out of rubber or cardboard, and let it end two inches from the ground.

[Cd]

It's going to be really interesting to see what the cars new Cd is when you test for that.
( Just don't do the testing anywhere near a GM aero guy. They would want the car retested with 17 " wheels )

[Sean T.]

Honestly, I wish I had the time or at least the motivation to do all that.

[thatguitarguy]

Originally Posted by RobertSmalls

It won't be a problem in the snow, since the front dam should gently push snow aside, and the rear dam will ride in the wake of the tire.

This doesn't sound right to me. The reason they have 10 ton front loaders moving snow around here is that it doesn't just gently move to the side. And every vehicle I've ever driven in the snow (many) has collected packed ice and snow inside the wheel wells. This much enclosure around a wheel could be a disaster. This configuration looks to me to be a dry weather set up.

It's a challenge to find low budget aerodynamic solutions. It's a real challenge to find a usable balance between a Bonneville test vehicle and a daily commuter.

[Nerys]

it will thatguitarguy

next time you have snow try this.

take a shovel and BROADSIDE a snow pile with it. Hard ehh? THATS a plow.

now take a kitchen knife and SLICE the pile with it? easy ehh? thats the aero mod.

its more knife like than plow like if its shaped properly and built out of more than cardboard for the final mod.

you WILL get ice build up though and your going to have to monitor/remove it as it builds up.

[thatguitarguy]

Originally Posted by Nerys

it will thatguitarguy

next time you have snow try this.

take a shovel and BROADSIDE a snow pile with it. Hard ehh? THATS a plow.

now take a kitchen knife and SLICE the pile with it? easy ehh? thats the aero mod.

its more knife like than plow like if its shaped properly and built out of more than cardboard for the final mod.

you WILL get ice build up though and your going to have to monitor/remove it as it builds up.

It doesn't sound like you have a lot of experience with driving in or plowing snow, but part of my point is: How do you monitor/remove snow from around an enclosed wheel?

[Christ]

Remove the enclosure as part of the weekly vehicle inspection that you should be doing to ensure your vehicle is safe to operate on public roads. They're not hard to remove.

[thatguitarguy]

I took this picture, not because it was that much snow, but because it was 2 days before Halloween. It is a little out of the ordinary to have that much that early. It has snowed plenty since then.

If you had driven a vehicle with an enclosed wheelwell in these conditions and then parked outside overnite, you would have spent a few hours destroying your wheelwell enclosure because the ice would have been caked completely inside and frozen to the wheel, the tire, the inside of the well, and the wheelskirt and all modifications, and it would take a heat gun to melt the ice in order to even be able to make the vehicle move. A weekly inspection ain't gonna cut it.

I'm not sure why some people want to have some kind of argument with anything someone else says, but I'm not talking about cars getting airborne at 200+ MPH, or any theoretical crap, I'm talking about the real world driving conditions that I personally have to face on a regular basis.

I'm not in any way saying anything negative about Darin's project. I'm very interested in it and I wholeheartedly applaud him. I will take the science that he gathers and apply it to my own project in time. But it will have to be different to be practical for where I live. I know when people are talking about cutting through the snow with a kitchen knife, or checking under their wheelskirts once a week, that they don't live where I live, or drive where I drive.

[Bicycle Bob]

Ice does not stick well to Coroplast, so it might be easy to get it off many aeromods. For hard cases, we might want to use greenhouse-garages to melt the buildup, or build in some nozzles to allow easy flushing from a hose. In salty areas, that can be good maintenance. I've seen mud that barely moves for a pressure washer, though.

[orange4boy]

I drove my van all winter with enclosed wheel wells and had no problems with slush packing. The slush build up happens with or without the skirts and the wheels just make their own space to move. You results may vary.

The front air dam is another story. I lost that in a snow bank. I pulled into a driveway and hit the bank a bit. When I backed out the dam stayed where it was. I LOLed.

Thing is, make your mods easy to remove if you are worried about it. Or take them off in the winter.