EV-1:America's fastest production car

[MetroMPG]

Phil, I've posted the picture of the record setting Impact / EV1 in its high speed livery from your album. It's up in the first post of this thread.

I have seen video of the actual speed run online somewhere as well, but I struck out in a search of YouTube just now. It would be great to put your photos & video on line.

Also, I don't want to stray from the technical discussion, but I have to admit my blood pressure goes up when I see recent GM ads promising the "first production electric car" (the Volt) sometime in the future. Was the EV1 not considered a production car? It strikes me that if GM's fairy godmother could grant it magical wishes, one of their first would be that the public would forget the EV1 ever existed! They certainly seem to be behaving like that's the case already. (Related thread: see http://ecomodder.com/forum/showthrea...-news-322.html)

[aerohead]

In my "cost of production" post I made an error.I had cited Daihatsu as associated with GM.I should have posted Daewoo(maker of the Opel-Kadett/Pontiac-LeMans clone).My apology to all offended parties.

[MetroMPG]

Originally Posted by aerohead

I'm putting a case-study together for the EV-1

One thing I'd be curious to learn, is why the EV1 digressed so far from the "ideal" teardrop profile which we've been discussing on EcoModder so much. And yet still had a fantastic Cd.

EG if you look at the examples in this image, the EV1's rear glass angle is furthest from the expected shape:

[roflwaffle]

Originally Posted by MetroMPG

One thing I'd be curious to learn, is why the EV1 digressed so far from the "ideal" teardrop profile which we've been discussing on EcoModder so much. And yet still had a fantastic Cd.

EG if you look at the examples in this image, the EV1's rear glass angle is furthest from the expected shape:

What about looking at an ideal tear drop from more than one dimension? The air can also flow in from the sides if they have sufficient angles to help w/ pressure drag in the rear. Look at the gen 4(?) Lexus LS 430 w/ a Cd of .26 and the recent Mercedes S class sedan at .26. Both have designs that diverge even more from the POV of a side profile, and look normal'ish, but they have Prius-like drag coefficients. Toss in no engine bay drag for an extra ~.02-.04 points off and there's the EV1's .19 Cd. IMO at least. Treb probably knows what's really going on, whereas I'm just talking outa my ass.

[MetroMPG]

I've been assuming that the ideal teardrop as shown applies in both plan and profile views. Could be wrong. Phil?

The EV1 had a lot of plan taper (the rear wheel track is 9" narrower than the front according to this site), and a pronounced conical shape from the rear window aft that doesn't really show up in most photos.

[roflwaffle]

I think it's all angles, not even just plan and profile, that should slope inward at a ~15 degree angle, or whatever it is, barring where it's obstructed by the road of course.

[jamesqf]

Originally Posted by MetroMPG

...but I have to admit my blood pressure goes up when I see recent GM ads promising the "first production electric car" (the Volt) sometime in the future. Was the EV1 not considered a production car?

On top of that, the EV1 was hardly the first production electric car. By about a century, in fact: Baker Motor Vehicle - Wikipedia, the free encyclopedia

[aerohead]

Originally Posted by MetroMPG

I've been assuming that the ideal teardrop as shown applies in both plan and profile views. Could be wrong. Phil?

The EV1 had a lot of plan taper (the rear wheel track is 9" narrower than the front according to this site), and a pronounced conical shape from the rear window aft that doesn't really show up in most photos.

Somewhere,there is a photo of the EV-1,taken from above in GM's windtunnel.From this picture you can see that the frontal area is achieved about halfway down the door,then the body begins the progressive plan taper,growing "steeper" the further back on the body,approaching Mair's boattail geometry at the rear,with very aggressive reduction in area.This is where GM is getting Cd0.188.------------------ I really believe that the roofline geometry is a compromise for rear windshield outward vision.If the backlite is very steep,vision suffers from refraction and also internal reflections.-----------------This is also why windshields may never be steeper than what we see in contempory cars.------------ Here again,GM gets around this with complete wrap-around convex windshield,theoretically the "perfect" windshield.-------------------------- We notice that the roofline is also "dirty" with GM's Ultralite and PNGV.--------------------- Both have separated flow over the back of the car,but decent rear vision.

[aerohead]

I took my VHS cassette of the EV1 land speed record with me on my recent trip. A friend in Fayetteville, Arkansas does video restoration/ transfer, and it turned out that the VHS was in perfect condition. And the footage has been transferred to a memory stick. I'll see if I can get assistance putting it here at EcoModder.
One particular image was taken far enough away from the car that, it approaches that of a technical image, from which critical measurements may be taken.
Lowered, and with the 'Yellow Ferret' aluminum boat tail installed, as best as I can tell, the tearing edge of the car has been moved rearwards where it intercepts the silhouette of the AST-III, just as Doctor Hermann Burst's, with the Porsche 911 Carrera RS 2.7 'duckbill' spoiler.
The Cd 0.137 of the EV1 matches the Cd 0.137 of the 1985 Ford PROBE-V concept, who's tearing edge silhouette also coincides with that of the AST-III. Something Dr. Hucho implored us to pay attention to.

[freebeard]

I'll see if I can get assistance putting it here at EcoModder.

AFAIK no way to upload it directly, but if it is hosted anywhere online you can use the button to link to it.