Aeromod the Electro-Metro

[bennelson]

Hey Guys,

Darin pointed out to me that if I start getting the Electro-Metro up to decent speeds, it's the WIND-RESISTANCE that's going to kill my watt-hours-per-mile!

With that in mind, throw your suggestions my way for AERODYNAMIC improvements to my modest EV.

This is a bit premature/hopeful, but I DO plan to crank my voltage to over 100, and with it, gain unprecidented speed!

The car is already lowered (due to battery weight!) so that's taken care of already. The passenger mirror is also removed.

I have always loved the baby-moon/pizza-pan hub caps, so I plan on those eventually. Anyone have 13" pizza pans?

I also liked MetroMPG's Firefly rear wheel skirts - very classy looking.

I am still trying to do all this on the cheap, and have PLENTY of other things to do on the car as well, but I thought I would just throw it out there!

-Ben

[MetroMPG]

One of the advantages of an EV is you can fully seal the grille/motor compartment and implement a full belly pan, because you don't have to deal with hot exhaust components. Maybe a very small allowance for a motor cooling intake duct.

After doing that, wheel discs, and the rear skirts (the pretty easy stuff), you need to focus on the back of the car. That's where the action is.



That Kammback is worth about a 5% improvement in fuel economy (range) at 55 mph, based on incomplete testing (only A-B comparison, not A-B-A).

http://ecomodder.com/forum/showthrea...sion-3518.html

[MetroMPG]

OH!

And since you're giving up the rear seat for battery space anyway...



Hey - this can be done cheaply. You didn't say easily.

http://ecomodder.com/forum/showthrea...ropped-90.html

[MetroMPG]

Thinking about this: the cool thing about improving aero on an EV is that the range benefit will be greater than the same mod on a gasoline ICE vehicle.

Reducing power requirement for a gasoline car reduces fuel consumption, but it also moves the engine further from the best BSFC island (assuming cruising conditions).

So let's say a particular mod returns a 5% range increase for a gas car. It's going to be greater than that for your EV because you're not penalized for reducing pressure on the go pedal, the way you are with the gas engine. In fact the EV gets an additional bonus: not only do you reduce power requirement for a given speed, but by reducing current draw you also reduce Peukert losses which increases range even further.

So a 5% fuel economy gain in a gas car is definitely going to be a greater than a 5% gain on an EV.

[aerohead]

I'd follow Darin's lead and if you can build the stomach for it later,do the full Monty, mimicing basjoos Aero-Civic.------------------- Down the road,as your sanity ebbs,consider a fully integrated complete boat-tail trailer with gap-fillers/tow-behind generator set for "hybrid" long-distance electric travel.Alan Cocconi and the Volvo team drove their EVs from Los Angeles to the Phoenix Solar-500 this way,except they didn't get the part about the trailer aerodynamics.You could make history!

[TestDrive]

Originally Posted by bennelson

The car is already lowered (due to battery weight!) so that's taken care of already.

Hope that's intended as humor.
First the overloaded springs take on a permanent sag.
Then sooner or later (depending on how overloaded) they break.

[bennelson]

I am only half-joking about the lowering. The car already was a low design, but it IS sitting low from the batteries. I do need to modify the suspension.

I am not finding any truely useful information anywhere about boosting the rear suspension.

It looks like the easiest thing to do about it is air-bags inside the rear springs.

[Bicycle Bob]

Maybe if you poke around a junkyard you can find some helper springs, or something that can be made to fit and has a little bit thicker wire in the coil.

Given that you don't have to worry about hot exhaust parts, you could do a very smooth belly pan, which is better than lowering and reducing underflow. The smooth, sealed front end sounds great, too.

[mattW]

The other great thing about aero-modding an EV is that you always have a precise measure of the exact power requirement to maintain that speed i.e. volts x amps. No more complex loop fuel measurements or expensive instantaneous fuel use displays... just check the amp-meter and note the difference... Should make testing a lot more conclusive

[Daox]

I'd definitely start with a full frontal block. Seal that puppy up. And you just got that nice roll of coroplast!