Impact/EV-1:a forensic reconstruction

[MetroMPG]

Robert - you just reminded me that another stat I'd like to know (estimate) about the EV1 is the physical area of the rear ("transom") of the car.

I tracked down a "rear-on" photo of it at one point to do this, but didn't follow through.

Assuming a vehicle has attached flow at the rear, this could be an interesting tidbit to compare against others.

[RobertSmalls]

The camera is awfully close in this photo, but based on the size of the license plate, the scale is ten pixels per inch. The transom is roughly 6.85ft². That's 34% of the EV1's 20ft² frontal area.

EDIT: I found a better photo, with specs for front and rear track drawn on it but mislabeled (track is measured from wheel center to wheel center). It suggests a transom area of 6.35ft², or 32% of frontal area.



For the Insight, I have this excellent image to work with:


And I find a transom of about 11.5ft², 57% of my frontal area!

Though the EV1 puts my Insight to shame, you should note that the area of the detached wake is >90% of frontal area on most cars:

[thatguitarguy]

Just a couple of observations and questions.

From this layman's perspective, one of the key elements to the overall shape of the EV1 is the narrower track of the rear wheels. I don't know if the Insight has this, but it seems to be a place that the designers of today's cars don't want to go. Why not? Is it because it looks too "dorky" for the mass car buying public? Is it that much less stable?

Granted the EV1 was a 2 seater, but the layout of many of today's cars places the wheels very far forward, and very far aft. It seems that with a focus on a 4 seater instead of a 5 seater, the shape could start tapering at the B columns, the rear track could be narrowed, the wheelbase lengthened, and there would still be plenty of storage space in the resulting quasi-boattail. With all of the microprocessors in modern cars anyway, it seems that they could come up with an active suspension to counter the roll of a narrower rear track.

[pgfpro]

aerohead thanks for the great post!!!

I don't have much to add because its out of my expertise, but I sure am absorbing a lot of info and would like to thank everyone that has contributed to this post.

[NeilBlanchard]

It is too bad there is not also a side view photo of the EV1.

[RobertSmalls]

[aerohead]

Originally Posted by NeilBlanchard

It is too bad there is not also a side view photo of the EV1.

Neil,we've found one,taken at Ft.Stockton during the speed trial.It's distorted a bit but design elements can be distinguished.
I'll get it posted ASAP unless one of the other members beats me to it.Hint-hint!

[binarycortex]

Originally Posted by Big Dave

The EV1 was a nicely designed car but it was poisoned by its 1880s-tech batteries. How good would it have been with a little diesel?

Originally Posted by cfg83

Big Dave -

About 80 MPG :

Thread: EV-1:America's fastest production car


CarloSW2

I think your forgetting something. What if you removed all the super heavy batteries and electric motors and electronics and just had a small diesel. I think it would easily be over 100 mpg probably in to the 120 - 130 mpg range. Look at what VW did. The original 1 liter concept had a cd of .159 with a 7.5 hp 300cc 1cyl N/A diesel and it managed 235 mpg. They have now changed it (for the worse) the cd is now .195 (the same as the EV1) it has a 2cyl 800cc TDI (half of a 1.6L TDI) that puts out 7 hp in eco mode and 25 hp in "Sport" mode and is a hybrid which added 201lbs to the car and it still manages 170 mpg. (Can I have the original please.)

[3-Wheeler]

Originally Posted by thatguitarguy

...I don't know if the Insight has this, but it seems to be a place that the designers of today's cars don't want to go. Why not? Is it because it looks too "dorky" for the mass car buying public? Is it that much less stable?...

The Insight also has inboard rear tire that are 2 inches narrower than the front.

And this does cause some instability in the snow, as the rear tires do not track in the same path as the front, making the rear end of the car jump around more than normal cars.

It does take some getting used to, and after a while you just realize it tracks straight, but moves around a bit at the same time.

Jim.

[NeilBlanchard]

Okay,

These pictures are confusing me -- the EV-1 front and rear views are at a different scale than the plan view. And the is the Insight really that much bigger than the EV-1? The rear wheel track (center to center) is wider (1.325m) than the out to out wheel width of the EV-1 (1.24m)?

I'm trying to scale them properly, so I can measure the areas in DataCAD...

Originally Posted by RobertSmalls

EDIT: I found a better photo, with specs for front and rear track drawn on it but mislabeled (track is measured from wheel center to wheel center). It suggests a transom area of 6.35ft², or 32% of frontal area.



For the Insight, I have this excellent image to work with:


And I find a transom of about 11.5ft², 57% of my frontal area!

If those measurements are correct, and I've scaled the bitmaps right, then the EV-1 transom is a mere 5.308 sq ft; while the Insight transom is 1.999sq ft.

The yellow grid is 1 foot squares, and if the outline is right, then the area reported by DataCAD is very accurate. The two rear views are scaled correctly AFAICT, and the Insight looks enormous! It the EV-1 really that tiny?