Building a 100mpg consumer vehicle

[Vekke]

If you are not asked to put two doors put just one. Less weight... Make big windows for emergency exit.

Looking good so far.
I specially like the fact you can "walk" to the rear seat

[drmiller100]

roll up and down windows is kind of nice on both sides.
identical sides is kind of nice.
The same side impact protection is kind of nice.
Doors have some weight, but it sure makes it easier to build if both sides are identical.

I put some new pics up.

[FXSTi]

Thanks for sharing more pictures. I bookmarked your site.

Kirk

[scottschreffler]

Looking at the pics if that weighs in at less than 1000 I'd be quite surprised....cool idea.... Lighten up though. Good lord.

[some_other_dave]

I like the pics, thanks for posting them!

I agree that the ride will be pretty "exciting" when the car corners very hard at all. The front wheels will, as mentioned already, stay relatively perpendicular to the road when the body leans. That should keep them hooked up nicely. The rear will go into positive camber, which will reduce its grip.

The solution, at least in this case, is probably to make sure you never have to drive near the limits of adhesion. That can be difficult to ensure, though.

A motorcycle tire for the rear would be counter-productive, as an MC leans the opposite way in a corner that a car leans.

If you went to a pure trailing-arm front suspension (like the Beetle had), the front wheels would always lean with the car, so they would go into positive camber at the same rate as the rear tire. I'm not sure how you can accommodate the Civic drive axles if you swap to a trailing-arm suspension, though. And custom suspension fab is a pretty non-trivial thing.

Hmm... How could you make a rear wheel that tilts the "wrong" way, like the fronts do? At least you'd only be fabricating on one end of the car....

-soD

[drmiller100]

The world is full of lots of people with reasons why nothing will ever work.

For those all hung up on stupid suspension crap, I invite you to spend as much time researching as you do tailgunning.

I invite you to research friction characteristics of radial tires given imperfect camber. I invite you to research the effects of caster on camber in corners. I invite you to learn what the friction circle is for a car. I invite you to learn about understeer and oversteer, and which a decent driver prefers. I invite you to learn about roll centers, center of gravity and the interaction of the two.

I have built more successful cars from scratch than the rest of the posters on this thread combined.

I am pretty sick of people talking about why crap can't be done, and stating a bunch of crap which has no relation to reality.

Obviously I am in the wrong place.

My dream is to find a forum where I can learn from and help others build fuel efficient cars.

I don't want to listen to a bunch of tailgunners spewing crap about why my car won't work unless they have personally tried something and can tell me their results.

Today I fiberglassed the front hood. Tomorrow I bolt the mold together and finish fiberglassing it.

[ProDarwin]

Originally Posted by drmiller100

I invite you to research friction characteristics of radial tires given imperfect camber. I invite you to research the effects of caster on camber in corners. I invite you to learn what the friction circle is for a car. I invite you to learn about understeer and oversteer, and which a decent driver prefers. I invite you to learn about roll centers, center of gravity and the interaction of the two.

Caster has nothing to do with your rear suspension.
Imperfect camber is working against you.
The rear roll center and CG are working against you.

I'm sure there are ways around the handling issues associated with almost zero rear roll resistance. Massive front spring rate? Massive front bar? After all, look at the T-rex 14R. Then again:

Car and Driver tested the Can-Am Spyder on the skidpad...

Speaking of cornering, we ran the spyder around the skidpad, and despite the harrowing thrill, it pulled just 0.65 g. Part of the reason is that the stability control is always on, but the low number also seems to be the limit of the three-wheel arrangement

I just fiddled with my suspension spreadsheet and set the rear-track to 0. Some funny things happen when you do this.

From an efficiency standpoint, I think this car will be impressive. From a handling standpoint it looks downright scary.

[ProDarwin]

Originally Posted by some_other_dave

A motorcycle tire for the rear would be counter-productive, as an MC leans the opposite way in a corner that a car leans.

Negative. The car does lean the opposite way, however it would still be sitting right on grippy tread, as opposed to the sidewall of a square car tire.

[drmiller100]

Originally Posted by ProDarwin

From an efficiency standpoint, I think this car will be impressive. From a handling standpoint it looks downright scary.

Have you driven a car like this? Have you ever built a car? How many G's will a car with a 60 inch front track weighing 1000 pounds pull?

Will it understeer or oversteer on dry pavement? Rainy pavement?

The answer is you don't know because you don't know the front to rear weight bias, tire selection, front roll center height, sway bar system, wheel rate, nor much of anything else.

You are basically talking out your ass, just like I am. Difference is I'm not making stupid bogus claims on something which doesn't even exist yet.

[ProDarwin]

1) No.
2) No.
3) Too many factors but... more than enough to roll over, given the right tires.
4) Too many factors
5) Too many factors

Front roll center height, swaybar "system", and wheel rate are all going to be the same as the DWB Civic front suspension you welded the car to. I am not talking out my ass, nor I am I making "stupid bogus claims". In fact I didn't make a single claim, only stated my opinion.

If you want to provide some real data, I'd be willing to make a prediction at what cornering load the car will roll over.

What is your wheelbase?
What about your front spring rate? (stock?)
Swaybar rate? (stock?)
F/R bias?
CG height?