SOhappy

I 've been involved with an SAE competition before (not the formula hybrid, but another one). Good stuff.

Just wondering if you could elaborate more on why your team chose gas over diesel, availability? I'm with the original poster. Seems to me like a diesel hybrid (ala Chevy Volt, not Prius) would be the answer...

tx_2500

ive asked this question at length among family, friends, co-workers, even here on DTR. If its good enough for a train, why not a truck? A diesel engine runs SO much better at at low constant RPM. Look at all the industrial grade stuff that uses diesel as a generator or to turn hydralic pumps, all at a constant low rpm. Trains, HD generators, bobcats, all modern tractors and construction equipment. Why the automotive market is still messing around with gasoline hybrids is beyond me.

bhaugen

There are very few tractors that run through hydraulics using hydrostatic drives. The transmissions are still mechanical, either powershift, straight gears or the newer CVT trans. The same for any other application where brute force is needed (ie dozers, scrapers, etc...) Hyraulics are very inefficient, lots of heat and friction losses. The same can be said for generating electricity. There is a loss when you generate the electricity and a loss when you covert that back to mechanical force. The big reason they do that is because the size and complexity of a gearbox needed for a train engine makes it cost prohibitive. Large Mine trucks use this same system.

I don't know why people get hung up on thinking trains are a hybrid. They are a Diesel Electric system. They have been around since the 1940's. It is nothing new. Hybrid is a new term that relates more to a hybrid mechanical electrical drive system that stores excess power in batteries to be used when the extra boost in power is needed above what the I/C engine can put out.

Dartmouth 12V

The decision was based on a bunch of simulations of an autocross course that we run. We designed two complete systems to what we believed to be the limit of their capabilities, then compared them. The two systems actually performed identically in the simulation but one of them was pushing the components more out of spec. The system using the diesel used batteries for accumulators. This was well matched because the diesel could put out continuous power and batteries have high storage capability so they just need a continuous charge. The system with supercapacitors had much less energy storage so the generation system had to peak at much higher power levels but not sustain it which was more suited to a gasoline engine. The real limit in the end was that the batteries could not accept a charge fast enough. The car is going to be about 650lbs and has 65kw which is on the order of 88hp so it has pretty good power to weight.

One thing that needs to be considered with putting motors in each wheel is gearing. Yes, you can get rid of your transfer case but you end up with 4 little reduction boxes because most of these motors run 5-10k rpm and the wheel speed at highway speed is only about 1/10th of that. To the poster who made the comment about driving through water and mud, that is true for DC motors but not for AC motors. DC motors are very hard to water cool so they can't be sealed since they are air cooled. AC motors are almost always water cooled so they can be sealed.

tinbanger

amen

warn winches can run underwater so the technology is already there.

i know if the research was invested that they would be at the very least more effecient........

Busboy

I watched a BNN show the other night about the Paris auto show. Chrysler had a 4X4 there that was powered by two electric motors and lithium batteries. One motor for each wheel on the same axle, the other axle was powered by a small diesel engine that also powered a generator. So the technology is out there just not in North America yet.

PaulDaisy

I am sorry but I developed an allergy to the word "hybrid". When I look at a Prius that makes 45 mpg, requires regular replacement of batteries that are in turn a huge energy hog to make, and compare it to a VW Jetta TDI that uses a classical diesel engine, no batteries to replace, and makes 50 mpg, I conclude that the industry AGAIN jumped on what the public bought into from all the media hype. Not on what really can make a difference in environmental protection and reduction of pollution.
General public is easily swayed by the use of catchy terms like "hybrid" or "tactical" or "assault". We see it every day, and sadly, it drives manufacturing.

SoTexRattler

You're right...
WW-II Diesel-Electric Submarine's drives are about the same as a D-E Locomotive... Derived from similar hardware...
The only glaring difference between a D-E sub's propulsion and a D-E loco's propulsion system was the addition of batteries (and the sub doesn't need electric braking).

"Hybrid" is beginning to be more of a marketing term rather than a good description of a powertrain's architecture.

K.

sled4fun

The main thing is to JUST START MAKING THEM! The cost will come down and the technology will get better with time.

Just think how computers were when they started compaired to now.
Memory storage then, compaired to now.
The first cell phones compaired to now.

They just have to start making it and it will get better & better, cheaper & cheaper.

CarlJensen

I remember, years ago, I used to get Mother Earth mag. They built two electric cars thet used a 12hp gas engine to run an aircraft generator and aircraft starter motor. They worked and could do about 75mph at 60 miles to the gal, if I recall correctly. It was a lash up but it worked. Both the generator and motor were 400 cycle units though that aircraft use. Expensive but much smaller units due to the higher frequency used. As freq goes up size goes down. Wish I still had those old issues now, it is an interesting idea.

biododge1

I think a diesel hybrid would be a great idea. the Chevy volt drivetrain setup is the way to go vs. continuous run of the motor(like Honda). 100mpg is way possible considering 70mpg is easily done with a Honda insight.
the Chevy volt is like a train in that when the batts are depleted the motor turns on and supply's electric power for the motor.

chainzaw

I agree with you Paul. The word "Hybrid" is a joke.

It's my firm believe that automotive companies know how and can build cars that get 80-100 mpg. They're just bed buddies with the the oil companies and they won't. I mean look what they're doing right now. Increase fuel economy by 5-10% and all of a sudden it's a green hybrid that's going to save the earth! Cars are not improving... they're just keeping up with the times.

96_12V

This article give a little more insight into diesel (in general's) future here in the US:
http://wardsautoworld.com/ar/auto_diesel_doa_us/

And Chainzaw - with all due respect - do you work in the automotive industry, in R&D? Because if you don't - I invite you to try and develop this yourself...? I've been there, and its' not quite as simple as making a good apple pie.

chainzaw

No i don't. And I'm sure it is difficult. However I've read and listened to too many reports of outstanding prototypes with incredible features and abilities to believe that we the consumer are getting the best auto manufacturers have to offer.

snoyes

"Chevy volt is like a train in that when the batts are depleted the motor turns on and supply's electric power for the motor"

Actually, more like a Diesel Submarine... Come to the surface, start the diesel motor, recharge to batteries...