Dual pumps and one kit ques
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From: northwest La
Dual pumps and one kit ques Before its said, I did a search. I have to 255 walbros to install. I have seen threads saying its ok to run one hot wire kit on 2 pumps as long as the gauge wire is sufficient. My question is, can I just but the regular ol hot wire kit I see sponsors selling? Or do I need a different kit with thicker wire? I plan on running the 2nd pump off a hobbs switch if this makes a difference on whether or not I will in fact need 2 kits. Or if a sponsor sold a kit including everything I need like the hobbs and hot wire kit for 2 pumps to do exactly what I want to do that would be great. Thanks
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From: northwest La
I've already got the pumps. Just trying to figure out what to do about the hot wire kit. Judging by your response I need 2. But why do I see some guys running 1? If I don't have to run 2 kits I don't want to
I wired both my pumps together and then just got a 30 amp relay from autozone and ran them both off that, the wire going to the relay went directly to the battery and the existing power wire runs the relay. I used 10 gauge wire for everything. I looked up the "hot wire kit". I sure wouldnt pay all that for a $4 relay and some wires.
Heres my dual 255 setup with a autozone relay. Works just fine.
Heres my dual 255 setup with a autozone relay. Works just fine.
You need heavy gauge wire 8gauge or bigger and each pump will need its own 30amp relay. DO NOT run them both at once they will produce too much heat over heating fuel killing the pumps and causing running issues. One hotwire kit will not work its designed for one pump only.
Wow, that picture is worth a thousand words. Personally, I would hesitate to have unshielded 20 Amps of current zip-tied next to my fuel supply, but that's just me.
taws6m6, You need wiring capable of carrying a consistent 10 Amps of current per pump. They are actually close to 9 Amps, depending on your voltage, but you want a safety margin. You can Google for the gauge required: A safe way is 2 runs of 10 gauge (12 gauge being marginal) or one run of 6 gauge (8 gauge being marginal). These numbers take into consideration that you really want 2% or less voltage drop end-to-end, and your total length will be 10-12 ft, depending on how you route it and where your battery is located.
If you plan on activating the second pump via a switch, such as the Hobbs you mentioned, you will need 2 relays; one for the first pump activated by existing wiring, and a second for the Hobbs switch activation. I strongly suggest not using factory wiring for power to either pump, it is marginal for the factory pump and inadequate for a high-power pump like the Walbro. IIRC, it is 16 gauge.
I personally run the Racetronix harness for my first pump, and found it an excellent value with high quality weatherproof components.
taws6m6, You need wiring capable of carrying a consistent 10 Amps of current per pump. They are actually close to 9 Amps, depending on your voltage, but you want a safety margin. You can Google for the gauge required: A safe way is 2 runs of 10 gauge (12 gauge being marginal) or one run of 6 gauge (8 gauge being marginal). These numbers take into consideration that you really want 2% or less voltage drop end-to-end, and your total length will be 10-12 ft, depending on how you route it and where your battery is located.
If you plan on activating the second pump via a switch, such as the Hobbs you mentioned, you will need 2 relays; one for the first pump activated by existing wiring, and a second for the Hobbs switch activation. I strongly suggest not using factory wiring for power to either pump, it is marginal for the factory pump and inadequate for a high-power pump like the Walbro. IIRC, it is 16 gauge.
I personally run the Racetronix harness for my first pump, and found it an excellent value with high quality weatherproof components.
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You need heavy gauge wire 8gauge or bigger and each pump will need its own 30amp relay. DO NOT run them both at once they will produce too much heat over heating fuel killing the pumps and causing running issues. One hotwire kit will not work its designed for one pump only.
Im not sure where you came up with this.....10 gauge wire is more than sufficient to run both pumps. Both running together wont even pop the 20 amp fuse I have on it (high side of relay). If it were drawing more then 20 amps.....the fuse would blow. 1 - 30 amp relay seems to work fine. Both run all the time. Havnt had an issue yet. When the 20 amp fuse blows i'll know that there is more than 20 amps required by the pumps.....they will draw what they need regardless of the wire size....too small of wire will then heat up because the the amps traveling through it....
You dont need to double the wire, electricity does not function like flowing fluid.
Last edited by pwrtrip75; Dec 16, 2009 at 01:46 PM.
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From: northwest La
What about your 2nd pump? Another racetronix harness? I am just looking for something as close to plug and play for hooking all this stuff up. I bought a dual pump kit with the y fitting and some hoses a while back and am just getting around to where I want to install it. I just never bought any harnesses. I have never messed with any fuel stuff before. Just looking for convenience, saftey and ease of installation above all with this install. Thanks
....And the wires coming from each pump both together dont add up to 10 gauge.
Im not sure where you came up with this.....10 gauge wire is more than sufficient to run both pumps. Both running together wont even pop the 20 amp fuse I have on it (high side of relay). If it were drawing more then 20 amps.....the fuse would blow. 1 - 30 amp relay seems to work fine. Both run all the time. Havnt had an issue yet. When the 20 amp fuse blows i'll know that there is more than 20 amps required by the pumps.....they will draw what they need regardless of the wire size....too small of wire will then heat up because the the amps traveling through it.... You dont need to double the wire, electricity does not function like flowing fluid.
Im not sure where you came up with this.....10 gauge wire is more than sufficient to run both pumps. Both running together wont even pop the 20 amp fuse I have on it (high side of relay). If it were drawing more then 20 amps.....the fuse would blow. 1 - 30 amp relay seems to work fine. Both run all the time. Havnt had an issue yet. When the 20 amp fuse blows i'll know that there is more than 20 amps required by the pumps.....they will draw what they need regardless of the wire size....too small of wire will then heat up because the the amps traveling through it.... You dont need to double the wire, electricity does not function like flowing fluid.
Copper wire
Wire Size 10 AWG
Voltage 12 VDC
length !0 ft (too short, probably, but get in the ballpark)
Load in Amps 10 (use a larger number than you expect, to give yourself a bit of margin)
You want a 2% or less voltage drop, standard Electrical Engineering values, which is what you get with 10 gauge AWG.
Research how much current a Walbro pump draws (it's over 8 amps, but not 9, so your fuse is adequate). Now enter in your best values, which could be as low as 17 Amps, you have a voltage drop of right at 3%, 50% larger than the goal.
It's your vehicle, do as you wish. But a wise person would also observe what the professionals do (such as Racetronix, Lonnie's Performance, Nasty N8, etc.).
And yes, electricity is like a fluid, it is a flow of electrons. http://www.school-for-champions.com/science/dc.htm
What about your 2nd pump? Another racetronix harness? I am just looking for something as close to plug and play for hooking all this stuff up. I bought a dual pump kit with the y fitting and some hoses a while back and am just getting around to where I want to install it. I just never bought any harnesses. I have never messed with any fuel stuff before. Just looking for convenience, saftey and ease of installation above all with this install. Thanks
Originally Posted by elias_799
for those of us that already have a single racetronix 255 pump with a hotwire kit, can i just buy another racetronix pump and another hotwire kit and make it work ?
taws6m6, you sound like you have the fuel plumbing items already. All you need is a Bosch relay circuit, GFGI. All you have to be concerned with is the placement of the Hobbs trigger and the relay. My Hobbs switch is in my charge pipe, my relay is protected.
elias_799, you could make it work, but it would be simpler and easier (IMHO) to build your own if you are so inclined. The sticky at the top of this section, though vague on specifics, is a good starting point.
My personal preference would be for someone to offer a supplemental kit for those who already have the Racetronix kit, but what do I know.
And I wouldnt put so much faith in that website calculator. Its pretty generic...rated way high to probably cover the person *** that made it.
http://www.engineeringtoolbox.com/am...uge-d_730.html
Here it says that a 15ft run of 10 ga. wire is good for 20 amps. So if its 17 amps like you say... What is wrong with one 10ga wire? And its actually only probably 11-12 feet long. Theres a bunch of websites that all say the same thing.
This calculator said I need 10 ga. up to 20 amps running 12 feet.
http://beta.circuitwizard.bluesea.com/#
All calculators are generiic, including yours. I merely selected the first one I found. I am sure the professionals just pulled that number out of the blue also.
As I said before, it's your car, do as you wish.
I wish you the very best of luck.
As I said before, it's your car, do as you wish.
I wish you the very best of luck.
It is gas and oil resistant wire. And inside is all sealed w/ heat shrink tubing. Sparks outside the tank wont do anything the gas tank is sealed.
And I wouldnt put so much faith in that website calculator. Its pretty generic...rated way high to probably cover the person *** that made it.
http://www.engineeringtoolbox.com/am...uge-d_730.html
Here it says that a 15ft run of 10 ga. wire is good for 20 amps. So if its 17 amps like you say... What is wrong with one 10ga wire? And its actually only probably 11-12 feet long. Theres a bunch of websites that all say the same thing.
This calculator said I need 10 ga. up to 20 amps running 12 feet.
http://beta.circuitwizard.bluesea.com/#
And I wouldnt put so much faith in that website calculator. Its pretty generic...rated way high to probably cover the person *** that made it.
http://www.engineeringtoolbox.com/am...uge-d_730.html
Here it says that a 15ft run of 10 ga. wire is good for 20 amps. So if its 17 amps like you say... What is wrong with one 10ga wire? And its actually only probably 11-12 feet long. Theres a bunch of websites that all say the same thing.
This calculator said I need 10 ga. up to 20 amps running 12 feet.
http://beta.circuitwizard.bluesea.com/#
OK each pump is capable of 9-10amps at 12 volts...oh and your car runs 14volts when running....oh and on initial startup of an electric motor draws alot more, length, connections....lots of variables to worry about. Stock 16ga wire on a stock pump drawing 4-5amps melts the connectors from over heating. I would say 10ga wire and 30amp relay each pump is pretty safe.
