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how are you guys running the dual walbros?? I mean do you have a switch for the second one or do you have it so that at WOT and WOT only they both are on, or at a certain RPM does the second pump come on?? ... right now i have a switch for mine but i think i need to have it on either WOT or RPM, I was wondering how or which wires you have to hook up the fuel pump to, so that I knows when to come on??
 

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Cheifbootknocka
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Morefaster said:
use the stock fuel pump ecu to turn on two relays and run them both pumps all the time...wire the relays in series so if one dies both pumps shut down.
Thats fine in theory but the relay can stay on if one of the pumps fails. Or am I missing something?
 

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(overspooled)
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a relay is more likely to fail than a pump which is why you should always have a wideband. Most of the time when a pump fails they don't fail completely they just reduce flow...that is why there isn't much you can do to fail safe for the two walbro setup...(that I know of) I guess if you were real scared you could monitor for current fluctuations all the time trigger it that way, but too much speculation. run dual denso's if you're worried about walbro's failing...

ponder this....would you be any less [email protected] if your bpu+ car lost the stock fuel pump at full boost???? <==either way, your going to do damage.....
 

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Cheifbootknocka
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Morefaster said:
a relay is more likely to fail than a pump which is why you should always have a wideband. Most of the time when a pump fails they don't fail completely they just reduce flow...that is why there isn't much you can do to fail safe for the two walbro setup...(that I know of) I guess if you were real scared you could monitor for current fluctuations all the time trigger it that way, but too much speculation. run dual denso's if you're worried about walbro's failing...

ponder this....would you be any less [email protected] if your bpu+ car lost the stock fuel pump at full boost???? <==either way, your going to do damage.....
I like to run a fuel pressure gauge.
But if you only have one pump, then most likely at failure the fuel supply will drop off enough to act like a rev limiter and just stop instead of loseing flow and grenading the motor.
 

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Wire the two pumps to the stock fuel pump ecu, no relay. Just hook them up in the tank like the one stock pump. You will have 9V operation most of the time, then 12V to the pumps when needed under wot.
 

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REVTECHRACING.COM
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supra400hptt said:
Wire the two pumps to the stock fuel pump ecu, no relay. Just hook them up in the tank like the one stock pump. You will have 9V operation most of the time, then 12V to the pumps when needed under wot.

no way i did that once and the fuel ecu took a dump. so theres only 2 right ways i see of doing so.. MUST use relays direct battery powering them to feed the right voltage. you can either have both running all the time or use the aem to turn on the second pump a few different ways. or micro switchs vac/boost pressure switch etc. but either way it is done must use relays to up the power to feed the pumps. stock wiring is to weak and is only good enough to trip a relay...
 

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I use relays and would recommend this method, but the stock fuel ecu has worked fine for many including supra400hptt, he has a great writeup somewhere BTW....
 

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Five years and still going strong with the factory fuel ecu running the two walbros. There is usually more than one way to get the job done, though. Many run off of battery voltage.
 

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supra400hptt said:
Five years and still going strong with the factory fuel ecu running the two walbros. There is usually more than one way to get the job done, though. Many run off of battery voltage.

However, did you reuse the stock wiring or did your increase the guage the wire? This amount of amperage through stock wiring is not safe. Someone calculated the draw out before and noticed the same issue. It work out mathmatically, however, IIRC, its right on the fine line of failure. There is no safety factor to allow for screwups.

I have seen multiple people fry pumps and or wiring due to this setup you are running.

Best idea is to run one feed line from both pumps via Y-block to the rail. The Y-block it to both ends to distribute evenly. With your wiring, you should a single power wire and a 60 amp relay to go to both pumps. Utilize the power wire from the stock ecu to trigger the relay. You should never wire the stock ecu to 12V continous. It will create issues with the AEM.

Also, make sure to have a ground wire 8guage from the fuel pump hanger to the chassis. Otherwise, you will fry a pump. You will also convert the stock + and - wires to both + wires in order to trigger the walbro pumps for power.

DP
 

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Cheifbootknocka
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Have you guys heard any reports of properly wired walbro pumps failing ?
 

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Only wiring upgrade I did was inside the tank. I needed to Y the two wires so I used something a little heavier gauge. And upgrading was really for the two supra pumps I ran way back in the beginning before switching to the walbros. I'd encourage anyone doing the wiring to wire it how you see fit, but it's been documented that two walbros are equivalent to one supra pump as far as maximum amperage they draw. Plus I have the benefit of them being in 9V mode for 90% of the time when I'm not at wot. But again, do what you're comfortable with. If I ever have a problem then I'll reevaluate how I have it set up. I had ran into problems using battery voltage with the fuel pressure fluctating as the voltage changed, so I went with the fuel ecu regulating it.
 

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supra400hptt said:
Only wiring upgrade I did was inside the tank. I needed to Y the two wires so I used something a little heavier gauge. And upgrading was really for the two supra pumps I ran way back in the beginning before switching to the walbros. I'd encourage anyone doing the wiring to wire it how you see fit, but it's been documented that two walbros are equivalent to one supra pump as far as maximum amperage they draw. Plus I have the benefit of them being in 9V mode for 90% of the time when I'm not at wot. But again, do what you're comfortable with. If I ever have a problem then I'll reevaluate how I have it set up. I had ran into problems using battery voltage with the fuel pressure fluctating as the voltage changed, so I went with the fuel ecu regulating it.


This is the same way i have them running. No problems to speak of. Just bumped the in tank wiring to 12 gauge.
 
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