Electric AC Cobra (looking to reduce high energy consumption - 489 Wh/mi)

[ev99saturn]

I don't really have enough miles or eyeball time on the gauges to be sure, but I think that its running between 120 and 200 amps.

Originally Posted by Ryland

How many amps are you drawing at 50mph?

[MetroMPG]

I think you need 10 posts before you can add links/photos. (Forum anti-spam measure.)

Feel free to make a few dummy posts to get over the limit.

[MetroMPG]

Originally Posted by ev99saturn

I have considered blocking the oval grill area with a sheet of clear lexan, just on the inside of the body opening.

That would help. Grille blocking is a well understood & proven drag reduction technique - better to send air around the relatively smooth body of the car than through the torture chamber of the motor compartment, only to spill into the aerodynamically "dirty" wheel wells & vehicle underside.

As you say, make sure to leave enough of an opening for controller cooling.

Another (possibly dumb) thought would be to put flat sheet under the car, covering as much of the length and width as is reasonable. Would that help reduce air friction and improve wh/mi?

Definitely. Ever seen the bottom of an EV1? Even better if you're also able to gradually taper upward at the rear.

If you've got some lexan, also consider making some disc wheel covers. (Attachment method is the tricky part.)

I also thought about trying to tilt the windshield back a little, as I do have a bit of room to play there.

That will probably also help, depending on the current angle. Is it flat glass? Some of these old roadster designs had such a sharp angle between the cowl & glass that they created a "bubble" of recirculating air at the base of the windshield. No modern car does that anymore. Raking the windshield will also slightly reduce the frontal area which helps too.

Not to discourage you, but keep in mind we're talking about mods that may make a few percent here & there.

[ev99saturn]

It's hard to be discouraged when I have an EV GRIN that goes from ear to ear.

If I ever feel down about the low wh/mi, I will just put it to the floor and the 'problem' will magically disappear from my mind.

Anyway, it looks like I came to the right place to get a pile of ideas!

Thanks to all for your suggestions!

Originally Posted by MetroMPG

Not to discourage you, but keep in mind we're talking about mods that may make a few percent here & there.

[2000neon]

That thing is cool! A grill block could certainly help out a little bit, and as was mentioned you can keep it back a little bit without hurting it's effect too much. The smooth underside, often called a belly-pan can also help. Not having exhaust hanging underneath would definitely make that easier.

One other thing to look into are wheel spats. Basically an air damn just for the tires, it is more efficient to direct air away from the spinning, turbulent tire. They don't have to be huge, and if you painted them black they will be relatively out of sight. Doing a search here should bring up a whole bunch of ideas for those.

Also,as mentioned, you could look into some sort of an air dam under the front bumper.

[Ryland]

315mm wide tires on the rear are really wide tires and I see they seem to only make that size in sticky rubber compound for being on the track, so that is also hurting your range by at least 10% if not more, so why not a set of tires/wheels for car shows and other events and a set for daily driving when you want that extra range? I would think if you went with something that had a vintage look to match the style of car wouldn't look out of place.

I know you said you didn't want to go with narrower tires but I think small compromises can be made.

Do you have a hard top or is there even an option for a hard top? or is it just a fair weather open top car?

[MetroMPG]

Found it!

Re: the windshield angle, the wool tufts in this photo show airflow separation ("bubble") at the base of the MGA windscreen.



From: http://ecomodder.com/forum/showthrea...none-7753.html

[madmike8]

I think you need a transmission or steeper gears in the rear. Motors are more efficient at higher rpms. Driving at 40-50 your burning more amps since the rpm is around 2k. A transmission would allow you to keep the motor in a more optimal rpm for a given speed.

Btw love the Cobra!

[ev99saturn]

Ya, I will have to consider getting some narrower tires if they are that much of a difference. The front tires are only 245 wide, maybe the same set on the rear, or would you go narrower all around?

No top for it now, although FFR offers both a hard top and a soft top add-on.

Originally Posted by Ryland

315mm wide tires on the rear are really wide tires and I see they seem to only make that size in sticky rubber compound for being on the track, so that is also hurting your range by at least 10% if not more, so why not a set of tires/wheels for car shows and other events and a set for daily driving when you want that extra range? I would think if you went with something that had a vintage look to match the style of car wouldn't look out of place.

I know you said you didn't want to go with narrower tires but I think small compromises can be made.

Do you have a hard top or is there even an option for a hard top? or is it just a fair weather open top car?

[ev99saturn]

Wow. One picture say it all! Thanks for digging that up!

Originally Posted by MetroMPG

Found it!

Re: the windshield angle, the wool tufts in this photo show airflow separation ("bubble") at the base of the MGA windscreen.



From: http://ecomodder.com/forum/showthrea...none-7753.html