# Car revamp-Controller move question



## ZANDARRR (Sep 8, 2010)

We have a 1991 Toyota MR2 that we are contemplating moving the controller, possibly about 6 feet to the front of the car. Will having that much more wire between the controller and the motor make a difference in performance? Or have any adverse effects whatsoever? Should we use a larger gauge wire than the 2/0 we are now using?
Thanks


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## Ziggythewiz (May 16, 2010)

Adverse effects are certain. Your resistance would increase by a factor of 4 (assuming current length = 2' and planned length = 8'). How that effect affects your performance is much less certain, but to completely offset the increased length would require your wire crosssection to also increase by a factor of 4, do they make 8/0?


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## major (Apr 4, 2008)

Ziggythewiz said:


> Adverse effects are certain. Your resistance would increase by a factor of 4 (assuming current length = 2' and planned length = 8'). How that effect affects your performance is much less certain, but to completely offset the increased length would require your wire crosssection to also increase by a factor of 4, do they make 8/0?


Zig,

Don't be ridiculous. Yeah, I'm sure they make an equivalent to 8/0. But get real. Figure the watts lost due to cable resistance and you are telling this guy to put an extra 10-20 pounds of copper aboard to save a few watts. Chances are he was oversize on the 2/0 he is presently using.

ZAND,

Your 2/0 should be just fine if you're under 230A average current. Zig is correct that increased length of cable does increase the resistance. But it is a pretty small power loss. Other than that, it will also increase the inductance, which is not a problem between the controller and motor. I'd keep the two cables adjacent to each other to minimized RFI.

Regards,

major


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## Ziggythewiz (May 16, 2010)

I wasn't trying to say 8/0 was necessary, just that you couldn't realistically increase the gauge to compensate for a relatively large change in length. Also, you couldn't make such a modification expecting no adverse effects whatsoever. As I said, the performance impact of separating the motor and controller is much harder to calculate than just the simple resistance involved. The resistance may not be a significant factor, but it would be similar to running your motor/controller config as they are now off a 5 gauge wire (or 3 10 guages) instead of the 2/0, which isn't something I would want to do.

I haven't seen any conversions (not to say they aren't out there) that have significant motor/controller separation, so I don't know if there's any real-world data out there.

The simple thing would be to test it out with a quick mounting and a test run to see if your performance or the wire temps are affected.


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## DavidDymaxion (Dec 1, 2008)

Don't forget those wires are antennas, and will emit more radio noise for longer lengths. You might lose your radio reception, but maybe it would function as a radar jammer, CB jammer, neighboring car radio jammer... 


ZANDARRR said:


> We have a 1991 Toyota MR2 that we are contemplating moving the controller, possibly about 6 feet to the front of the car. Will having that much more wire between the controller and the motor make a difference in performance? Or have any adverse effects whatsoever? Should we use a larger gauge wire than the 2/0 we are now using?
> Thanks


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## Ziggythewiz (May 16, 2010)

As major mentioned, running the cables adjacent should minimize that. 

I don't suppose we have any threads on the opposite, do we? Say accidently designing your wiring to create a radio dead zone...I think this would be an excellent way to make the streets safer while maintaining plausible deniability...


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