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 09-10-2012, 08:42 PM #21 (permalink) EcoModding Lurker   Join Date: Jun 2012 Location: Connecticut Posts: 32 Thanks: 0 Thanked 0 Times in 0 Posts Ooh ooh ooh! You guys have bigger motors! The 3.5 hp motor in mine has a rating (according to someone online somewhere) of 98 amps @ 36 volts. So lets see how that goes: 36*98=3528 3528/750=4.704 3.5/4.704=.744..... 74% efficient sounds reasonable using just ratings here Now what should I be pulling with 48 volts? 48/36=x/98 36x=4704 X=4704/36 X=130.... Right where it looks like I am on that paper he wrote up and taped on! Yes we do pull over on that hill that gets us down to 15mph... Maybe some used lithium cells and an Alltrax 4865 or 7245 (I think those are the two models...) I'm not sure yet...lol
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 09-10-2012, 08:42 PM #22 (permalink) EcoModding Lurker   Join Date: Jun 2012 Location: Connecticut Posts: 32 Thanks: 0 Thanked 0 Times in 0 Posts Ooh ooh ooh! You guys have bigger motors! The 3.5 hp motor in mine has a rating (according to someone online somewhere) of 98 amps @ 36 volts. So lets see how that goes: 36*98=3528 3528/750=4.704 3.5/4.704=.744..... 74% efficient sounds reasonable using just ratings here Now what should I be pulling with 48 volts? 48/36=x/98 36x=4704 X=4704/36 X=130.... Right where it looks like I am on that paper he wrote up and taped on! Yes we do pull over on that hill that gets us down to 15mph... Maybe some used lithium cells and an Alltrax 4865 or 7245 (I think those are the two models...) I'm not sure yet...lol Also, sorry about typos being...everywhere...I'm typing on a 4.0" screen...
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Quote:
 Originally Posted by Hogwit Ooh ooh ooh! You guys have bigger motors! The 3.5 hp motor in mine has a rating (according to someone online somewhere) of 98 amps @ 36 volts. So lets see how that goes: Yes we do pull over on that hill that gets us down to 15mph... Maybe some used lithium cells and an Alltrax 4865 or 7245 (I think those are the two models...) I'm not sure yet...lol Also, sorry about typos being...everywhere...I'm typing on a 4.0" screen...
Hills that draw you down that slow can also blow brushes if you aren't careful.

If you insist on high speed driving with a C-car I recommend you emulate what was done with the Comutacar and lengthen your wheelbase (aka push the rear axle back).

I also recommend plug braking because C-car brakes work well when they work correctly, but are not reliable.

That said I did drive my Comutacar down the highway many times hopping down the road at about 50mph, most I ever got was 62mph down a steep hill. I had to turn the wheel into every 4th hunk of cement road or the car started bucking like a bronco. I have also ridden in a Citicar, mine seems to be more stable, if you are good at suspension and alignment you will need to tinker a lot to get it in form, same with the brakes.

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Ryan

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Quote:
 Originally Posted by rmay635703 If you insist on high speed driving with a C-car I recommend you emulate what was done with the Comutacar and lengthen your wheelbase (aka push the rear axle back).
How much longer is the Commuti-car wheel base? I thought they had the same wheel base, but I've never measured to see for my self.

As for the motors on the commuti-cars being larger, I don't think that is the case, TomEV has said, and my research seems to agree, that they are the same motor in the 36v Citi-car and the 48V Commuti-car, other then of course what Ryan has in his Commuti-car... Ryan, you have a D&D motor, right? but the GE motor the Commuti-car and Citi-car's use are the same other then the forced cooling that the commuti-cars have giving them a different rating, their raw power output tho should be the same, their brushes and field windings at least are the same.

TomEV also had Helwig Carbon make special two piece brushes with dual leads on them that can handle more current and they shouldn't bounce as much so there should be less arcing, not sure if he has any spare sets or how much it would cost to have them make up more based off the spec sheet that they have on file, I have a set of these upgrade brushes seated in to my Commuti-cars motor and the motor is ready to install... a project that has been on my to-do list for a few weeks now.

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Quote:
 Originally Posted by Ryland How much longer is the Commuti-car wheel base? I thought they had the same wheel base, but I've never measured to see for my self. course what Ryan has in his Commuti-car... Ryan, you have a D&D motor, right? but the GE motor the Commuti-car and Citi-car's use are the same other then the forced cooling that the commuti-cars have giving them a different rating, their raw power output tho should be the same, their brushes and field windings at least are the same.
Every C-car was slightly different

There was the old style Citicar, the transistional Citicar, the original Comutacar, the transistional Comutacar and the last Comutacar.

My car as far as I can tell has at least 6" more wheelbase and a bit more space in the wheelwells than the Citicar I saw. I believe it is somewhat related to how the battery boxes changed position and because of the size difference between a 4.80x12 and a135x80r13.

Of coarse my car may have been slightly modified because I have a 9" D&D motor.

Understand that the 3.5hp motor was only on the Terrell axle cars (doesn't matter if its a comuta or citi)

Later cars (1980/81/82) really could come with a 6hp or 8hp motor (of coarse they all had forced air as far as I know)