My new hopefully more aero Metro front bumper

[freebeard]

Looks good and pedestrian friendly. A little higher will compensate for reaching further forward in the approach angle.

[Cobb]

Cant wait for the outcome. I notice the car manufactures are more focus on a flat front end where as the project cars and such for eco challenges go for angles, points, etc.

[deejaaa]

looks good so far.

[California98Civic]

Originally Posted by Cobb

I notice the car manufactures are more focus on a flat front end where as the project cars and such for eco challenges go for angles, points, etc.

There was a thread on stagnation point a few years ago, with the below image in the lead post. Very useful discussion. Here is the key post in the thread, besides the first: http://ecomodder.com/forum/showthrea...tml#post167922

[serialk11r]

Originally Posted by Cobb

Cant wait for the outcome. I notice the car manufactures are more focus on a flat front end where as the project cars and such for eco challenges go for angles, points, etc.

That might be for crash safety? Flat bumper has a better chance of making it out of a low speed collision alive maybe. Since the whole front end has a lot of stagnant air I would guess that the front splitters people like to add have the same effect as angling the front end (let's ignore for now the fact that sometimes these splitters can actually make the aerodynamics worse) but you almost never see them on factory cars. I bet this is for collision safety.

[freebeard]

...but you almost never see them on factory cars. I bet this is for collision safety.

Approach angle.

[Frank Lee]

Originally Posted by Coyote X

This car already has weight reduction and a slightly more aero back bumper. It is another leftover from the old Metro project At least it lets the air pass through better than a solid bumper.

No way. I thought we disproved this?

[California98Civic]

Originally Posted by Frank Lee

No way. I thought we disproved this?

Oooh yah, speed holes!
http://ecomodder.com/forum/showthrea...mpg-20113.html

[basjoos]

One advantage of an angled front bumper is it acts as a wedge to lift deer over the top of your car with minimal damage to the front of your car when you run into one. Instead of a flat bumper absorbing the collision energies, the angled bumper redirects the collision energies upward. I've had this happen twice with the aerocivic, two deer collisions at 45mph, two deer lifted over the top of my car with only a slight dent in the hood and a cracked headlight lens to show for it.

[Coyote X]

Have you ever looked under a metro back end and seen how low the bumper is compared to everything else under the back? I would probably have to cut 6 inches off the bottom to get it level with the rest of the underside.

Besides it proved itself in this situation with coastdown testing. I have a 4% grade that is 2 miles long that I use for all my coastdown testing.

The front bumper really makes the car drive different. With all the air going over the top of the car it feels like I have sway bars. It keeps the front end planted solid to the ground, so a sharp curve I can normally take at 35 with a bit of tire squeal I took at 40 with no squeal today. I kind of like the way it makes the front end seem much more stable than a Metro ever did at 70mph. I think the bumper is helping the car though I had a really hard time holding 55 and was constantly drifting up to 60-65mph today. The car just felt like a different car. I normally get 60mpg on the trip I did today of about 40 miles. Today I got 66mpg. One day doesn't mean much but from the feel of the way the car coasts it has to be an improvement. I will need to cut a small vent into it since the fan was cycling while I was driving.

On that chart it shows a bit of air going under the car is ok. If I bent the bottom inch or two under to get more of a point does anyone think that would be better than the way it is now? I could probably just build a small lip under the radiator to push the underside air through the radiator and save from cutting a vent hole in the bumper If I did.

Here is a preview of tomorrow's post if I get time to get it done