Size of wire??

bdixon · 05-06-2010, 09:01 PM

When wiring like say a electic fuel pump is it an advantage to usr bigger dia wire or can bigger pull more juice???? thanks in advance for any help bryan

FED 387 · 05-06-2010, 09:14 PM

If your wire size is to small and the distance from the powersource(usually the battery) to the pump is fairly long you will have a drop in amperage. The pump manufacturer will usually give you a recommendations as to what size wire to use but in no case should you use a wire size that is smaller than the wires on the pump for optimum pump output as well as preventing the pump from overheating.
It's all about Amps not voltage your gonna get 12 volts but the Amps will drop due to small wire size and distance !!

cad · 05-06-2010, 09:27 PM

Install a relay inline with the pump and you will not have to use large wire.
http://www.painlessperformance.com/Manuals/50102.pdf

Moparteacher · 05-06-2010, 09:33 PM

The longer the wire the greater the resistance. Double the length of the wire and you double the resistance of the wire.

The larger in diameter the wire the less resistance in the wire. You can't go too big.

The resistance of the wire adds to the resistance of the circuit overall. As resistance goes up, current goes down.

12-14 gauge wire should be more than sufficient for a fuel pump in any race car. The smaller the gauge the larger the wire.

FED 387 · 05-06-2010, 09:53 PM

Thanx Gary--thats what I was trying to say!!! I know what it is just not how to put it down on paper--Comp 387

GTX JOHN · 05-06-2010, 11:37 PM

We run a dedicated fused hot wire from battery t o a relay (10-12 gage) and then to pump. Relay is switched thru ignition switch and then separate . switch on dash (14-16 gage). Fuel pressure seems steadier even with Holley or Mallory 140 with this direct set up.

72Malibu · 05-07-2010, 05:43 AM

Electricity is like water, ya just need a bigger hose

BlueOval Ralph · 05-07-2010, 06:23 AM

When using a relay you should be carefull how you mount the relay and in what direction, so that on accell the G-forces does not shut the relay off! Just a FYI

Quote:

Originally Posted by bdixon

When wiring like say a electic fuel pump is it an advantage to usr bigger dia wire or can bigger pull more juice???? thanks in advance for any help bryan

novassdude · 05-07-2010, 03:09 PM

Do not forget the ground side of the wiring needs to be just as large as the power wire.

Mack Reeves · 05-07-2010, 05:38 PM

Quote:

Originally Posted by novassdude

Do not forget the ground side of the wiring needs to be just as large as the power wire.

I also pull a large ground from the battery to a ground strip terminal and then pull to the other accessories. I don't trust just grounding to the frame...

05-06-2010, 09:01 PM	#1
bdixon Member Join Date: Dec 2009 Location: mitchell sd Posts: 288 Likes: 4 Liked 15 Times in 7 Posts	Size of wire?? When wiring like say a electic fuel pump is it an advantage to usr bigger dia wire or can bigger pull more juice???? thanks in advance for any help bryan

05-06-2010, 09:14 PM	#2
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,354 Likes: 337 Liked 281 Times in 151 Posts	Re: Size of wire?? If your wire size is to small and the distance from the powersource(usually the battery) to the pump is fairly long you will have a drop in amperage. The pump manufacturer will usually give you a recommendations as to what size wire to use but in no case should you use a wire size that is smaller than the wires on the pump for optimum pump output as well as preventing the pump from overheating. It's all about Amps not voltage your gonna get 12 volts but the Amps will drop due to small wire size and distance !!

05-06-2010, 09:27 PM	#3
cad Senior Member Join Date: Apr 2009 Location: Omaha, NE Posts: 675 Likes: 141 Liked 72 Times in 40 Posts	Re: Size of wire?? Install a relay inline with the pump and you will not have to use large wire. http://www.painlessperformance.com/Manuals/50102.pdf

05-06-2010, 09:33 PM	#4
Moparteacher Junior Member Join Date: Nov 2007 Location: Boise Posts: 49 Likes: 0 Liked 0 Times in 0 Posts	Re: Size of wire?? The longer the wire the greater the resistance. Double the length of the wire and you double the resistance of the wire. The larger in diameter the wire the less resistance in the wire. You can't go too big. The resistance of the wire adds to the resistance of the circuit overall. As resistance goes up, current goes down. 12-14 gauge wire should be more than sufficient for a fuel pump in any race car. The smaller the gauge the larger the wire. __________________ Gary Weaver Moparteacher@yahoo.com

05-06-2010, 09:53 PM	#5
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,354 Likes: 337 Liked 281 Times in 151 Posts	Re: Size of wire?? Thanx Gary--thats what I was trying to say!!! I know what it is just not how to put it down on paper--Comp 387

05-06-2010, 11:37 PM	#6
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,545 Likes: 2,242 Liked 1,886 Times in 580 Posts	Re: Size of wire?? We run a dedicated fused hot wire from battery t o a relay (10-12 gage) and then to pump. Relay is switched thru ignition switch and then separate . switch on dash (14-16 gage). Fuel pressure seems steadier even with Holley or Mallory 140 with this direct set up.

05-07-2010, 05:43 AM	#7
72Malibu Junior Member Join Date: Nov 2008 Location: Republic,Mo Posts: 93 Likes: 0 Liked 0 Times in 0 Posts	Re: Size of wire?? Electricity is like water, ya just need a bigger hose __________________ * 72 Malibu * 1.329-3.99-6.28@106.71-9.98@131 best 60ft to date-1.2997

05-07-2010, 03:09 PM	#9
novassdude Senior Member Join Date: Mar 2002 Location: usa Posts: 751 Likes: 203 Liked 133 Times in 49 Posts	Re: Size of wire?? Do not forget the ground side of the wiring needs to be just as large as the power wire.