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Old 06-03-2020, 10:01 PM   #22
Scooby Specialist
Member#: 110994
Join Date: Mar 2006
Chapter/Region: MAIC
1990 ED7


Originally Posted by 2slofouru View Post
If you split the oem wire on the hanger for both pumps and are still using the oem connector on top, you may be losing a lot of voltage. The oem ground for the pumps goes all the way to under the passenger front seat on my old impreza, and if yours is also there you can lose a lot. The oem pins for the hanger connector are very tiny and won't handle much pump current. Also factor in that there are two sets of contacts the power has to run through for the connector...the ones outside the hanger and the ones where the pump harness in the tank plug in to the hanger. You could also consider the connectors at the pump, but most people probably aren't going to solder them for risk of warranty denial.

On my modded oem hanger I have an aftermarket connector also added and have both the oem two wires and the ones from the other connector going to the same pump. I originally was going to use the 400 pump and it draws a good bit over stock, but ended up with a 300 for now the hanger is major overkill.

-Is your hanger running on the oem speed controller or straight from a relay with a dedicated thick wire from the battery?

-I'd also recommend running two of the same pump if they are paralleled on the hanger. Someone may chime in saying they believe it's fine, but something about two pumps with different flow and relief valve pressure worries me. Also one pump may have a check valve with the other not. Something to check into.

Either way, seeing several people running two pumps has convinced me to buy another (hnnnhghhhhhh) DW400 to install in the surge tank. Two will surely get rid of my only limitation. May as well make full use of the 2000cc injectors!
I have the stock connector as i couldn't decide on another solution, i did de-pin all of the wiring and solder new wiring on the internal side and on the other side as well. I have no FPC, using 2x DW hardwire kits, my grounds come right out of the hanger and goto the RR strut mounting.

To power two pumps i deleted the fuel temp sensor, de-pinned, then soldered in thicker gauge wire, each pump has it's own dedicated power and ground wiring. Yeah the 2 different pumps was only because thats what I had on hand when i was putting the car back together (was running out of time).

I plan to grab another 525 that way when i work on the fueling i can swap the 450 out and i'll have matching pumps.

I've been considering installing a surge tank and going to a single lift pump, but i havent committed to that yet.
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