# Help! I have an idea



## gmijackso (Sep 30, 2008)

The HP required is determined by your definition of highway speeds, the frontal area of the vehicle, and the drag coefficient of the vehicle (how flat or aerodynamic it is.

The torque required is going to be determined by the final weight of the vehicle, the final gear ratio (rear end), the gear ratio of the transmission, and your expected acceleration. Once you have enough torque to break static friction, you'll eventually accelerate to whatever speed, but if 1 month is too long to wait to get to 55, then you need to say so.

The volts/amps is going to be determined by the final speed, and the drive train (transmission and rear end), giving you the RPMs required by the motor and the voltage associated with that. 

Basically you need to make some decisions. You've basically asked what you need to build an electric car and want specifics with no other criteria than I want an electric vehicle that weighs X. 

Also, what do you mean by no batteries? Are you suggesting you wish to power this with solar, an internal combustion engine, capacitors, telekinesis? I'm not sure what you're asking here.

Maybe check the FAQ and the wiki, they'll help you get some of the questions you need to answer on your own before any real help can be given.


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## vgslimo (Oct 21, 2008)

Dances with rims said:


> Second, I want to eliminate the need for batteries and generate the power directly to the motor. Any suggestions or objections?


sounds to me like your trying to build a series or paralell hybrid. you can search either of those topics and read the previously stated threads and advice (both good and bad). here is one way to draw the voltage/amps you may need but you will have to consider how you would power it (ie. small diesel motor/ gas motor..)_http://cgi.ebay.com/HighAmp-PMA-Perm...QQcmdZViewItem_. i'm trying to map out all the specs for a good clean renewable fuel series hybrid myself and i know your troubles with finding help in this area as most of the people don't need the range that we do. there is however some very good advice available here from some really intelligent people so just dig hard and you can find most of the answers here even in some of the haters posts as they tell you what to look for even as they degrade your process! lol good luck.


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## ClintK (Apr 27, 2008)

Dances with rims said:


> Yes, ladies and gents. Another newbie who thinks he's found the holy grail. I've had this idea in my mind for several months now and I can't shake it off. So I need you guys to set me straight, math wise, so I can share it with you, good or bad.
> 
> First, what would be the best motor for: Gross vehicle weight 5000 lbs. 4 speed automatic transmission and final drive gearing to match optimal motor output at regular highway speeds. I'd like to know in HP, FT/LBS and Volts/Amps.
> 
> ...


The EV calculator at http://www.evconvert.com/tools/evcalc/ might give you some good ideas about the hp/torque/volts/amps requirements.

I played around with an S-10 for you and got http://evconvert.com/tools/evcalc/?...0:rim=14:rr=0.015:bs=0.003:kwh=0.09:miles=20:

For us to tell you the best motor would require a lot more info. Budget, desired, range, etc...


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## Dances with rims (Oct 24, 2008)

gmijackso said:


> Basically you need to make some decisions. You've basically asked what you need to build an electric car and want specifics with no other criteria than I want an electric vehicle that weighs X.
> 
> Also, what do you mean by no batteries? Are you suggesting you wish to power this with solar, an internal combustion engine, capacitors, telekinesis? I'm not sure what you're asking here.
> 
> ...


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## gmijackso (Sep 30, 2008)

Dances with rims said:


> gmijackso said:
> 
> 
> > My train of thought (no pun intended) revolves on the fact that a 'diesel' locomotive is actually a very large and powerfull electric car with no steering. I want to downsize that because my thoughts revolve around the deisel part. If there is an electric motor out there that can match a gas V6 in a full-size pick-up truck and can figure out optimal constant power input requirements, then I think I could probably suggest a means of supplying it.
> ...


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## vgslimo (Oct 21, 2008)

nice info! great easy to understand reply!


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## gmijackso (Sep 30, 2008)

I should add, that the diesel figures above are for a non-turbo diesel. If you're turbo, you'll get some more efficiency.

It should also be added that for the weight they carry, diesel-electric trains are very efficient. I think the analogy is something like, if you were to take the weight of a loaded train and spread it across fully loaded tractor trailers, each tractor trailer would have to achieve 55MPG to have the same efficiency.

But, as I said before, I still don't think it's practical on a small scale, and a car/truck is a very small scale when compared to a train. Every watt of small inefficiency is a much higher percentage of the total power in something small scale than it would be in a train.


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## kugmo (Oct 31, 2008)

Good luck on your idea, lolz...post some update and progress of the project.


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