High Mileage Vehicle

[Herpderplol]

So our school has a tech club (im guessing most do?) This is some cool stuff we are doing.

Giz is on the electric car, and solar trailer if he wants to share about it he can...

I am leading the Super Mileage car. We have had the frame and body done for 4 (?) years. This is my first year running the car as the leader.
I have a few other people "helping" with the project.

Our supervisor is somewhat of a procrastinator, and hates spending money (he will get grants for everything!)

Anyways, we had to write our proposals to enter the vehicles in the last week. So now we are working on the cars.

So far there are no modifications done to the engine, we have a junior 206 briggs engine. We literally probably get 2 mpg (yeh, super mileage car right?)

How the car was run last year is by running the engine to get up to the 25 mph (limit is 25) and killing the engine. Coasting until almost stopped, start the engine and go again. The track is 3 miles on one lap. To qualify we need to make it 2 laps...

We are running in a modified class, just what my instructor chose.

So, what am i getting at? Not much, just making a thread about it, and will post some pictures in the coming days when we work on it.
Also, looking for any ideas on how we could get better mileage. I have google searched a lot.

Things NEEDED:
Order a new camera and screen (required to have rearview mirror or camera)
Get disc brakes on rear (running bike style pinch, they DONT work....)
Install windshield (have it, too hot last year to drive with it on)
^^^Also means we need cooling - I plan to put small vents on the sides of the body to draw air in, and giz said use air duct piece in the front to scoop air.
Need to figure out a way to remove the person from the vehicle in 15sec (by themselves) The electric car has a hinge on the front, with a wobbly support to flip up (we have looked into using the piston things from topper doors or trunks, but they dont have enough movement to open the vehicle)

Plans I would like to do:
Lightened flywheel - Faster rev to get up to speed faster
Run on vapors, not gas - http://fuel-efficient-vehicles.org/energy-news/?page_id=785

I think we could go a long ways on the vapor idea, but its something we have to try...

Unfortunately, we are unsure if that idea will work. And the proposal is due tomorrow... Which means i either put that we are running on vapor and hope it works, or i dont put that and we run in exhibition class (no trophies, just trials) if it does work.

Any questions, comments, or ideas post below. I:I

 

[harley1-5]

sounds cool so now you are herp the mad scientist

 

[tbrooks]

Does it really save fuel to cut the engine off and then have to restart and accelerate again vs. keeping constant speed? I guess with that inefficient of an engine it might. Do you guys have any type of gear box on it. Otherwise increasing aerodynamics and reducing friction if you can, air scoop is gonna slow you down some

 

[Herpderplol]

Does it really save fuel to cut the engine off and then have to restart and accelerate again vs. keeping constant speed? I guess with that inefficient of an engine it might. Do you guys have any type of gear box on it. Otherwise increasing aerodynamics and reducing friction if you can, air scoop is gonna slow you down some

Restarting it takes about one turn of the starter, so its not using more gas in that sense.

We are using a go-kart style shaft clutch (we should and would like to upgrade to something else)

I will post a picture of the electric car (same as gas, just no gas pictures) The body is very aerodynamic already.
We need the vents for cooling inside the "cockpit". Last year it was so hot they had to take out the windshields to cool the drivers.
And as you can see from the picture, why we need the wind shield for aerodynamics...

Also, the gas car is black with orange flames.
Our solar boat is black with green flames

 

[tbrooks]

oh yeah in which case air scoop would be an improvement lol. And of course changing the color of the car may help with heat, but black is supposed to release heat faster as well as absorbing it. Not so much the starting that takes fuel but accelerating back up to 25 again, as accelerating burns more fuel than holding speed, of course this depends to on how flat your course. I would be interested to see if some sort of weight off-center on the tire would create sort of a pendulum effect and help you coast farther but it would probably hurt your acceleration. Anyway you could give it even a high lo gear would help tremendously I think. if you could get to speed and have it geared in a way that the engine was running low rpms and able to maintain speed

 

[Herpderplol]

Well the speed limit during the race is 25mph

Estimated speed of 38.645 mph (not a fun math equation...)

Its not easy holding at a steady rpm with the throttle. The throttle is part of the steering wheel. If we switch to the gas vapor, we would put a valve up front

If you havent, watch the videos about gas vapors, the second one down is pretty cool, and best shows it working

 

[tbrooks]

That is a good idea and makes perfect sense since the fumes are what burns anyway. I thought before looking at the link you meant some sort of gasification process, and I guess it kind of is but that is much simpler. There are lots of things that could make a big difference long range, but on that short of a run its not as easy to improve efficiency. I'm sure that different rates of acceleration have different efficiency as well but may not matter and your vapor will help overcome a lot of that.

 

[Herpderplol]

Like said in the artical, the carbs push small droplets of gas and vapor into the engine, it burns the vapor and the gas is waste.
So it makes perfect sense to run on the fumes. Im hoping this will fly with the people running the show... there are a lot of rules, but not many on the actual engine itself. Im thinking, if we get disqualified its because we modified the gas bottle (it has to be a certain one) they may not like it...

I believe we run until we are out of gas, but im not sure... I havent read the book of rules and stuff, just skimmed over what was needed to enter...

some of our wrestlers are in the state finals tomorrow, and there are some buses bringing kids down there. Im hoping my class (already 8) is small enough to where we can skip the day to work on projects (same teacher is tech adviser)

 

[Larry's Shee]

Nothing like the night before to do your project
Don't think I'd be grooving on a gas valve by my face

Maximum safe pressure in tires.
Remove any seals from wheels.
Clean wheel brgs, use oil , teflon lube, sno-mo clutch lube (mulibdnium disufide) no axle grease
Use thin synthetic oil in engine 0-5w
How well is body sealed? If tight, use small opening or scoop in front/front side for air intake, rear facing scoop above and behind drivers head (slightly larger than intake area) driver cooling.
Make sure brakes aren't dragging.
Is 25 max or min speed? I think constant min speed would be best, or rpm engine is happiest at (gear change?)
Reduce weight to min allowed. If allowed ditch battery maybe starter, use external starter. If must be self starting use smallest battery posible (1 start?) disable charging system

 

[Herpderplol]

30 is max speed, i thought it was 25, but giz informed me