Fixing the GD WRX Fuel System with Radium Engineering and DeatschWerks

The Radium hanger has a sump.  The sump helps reduce the likelihood of fuel starvation under cornering. It holds a few seconds worth of fuel to keep the pickups submerged in case the fuel in the tank sloshes around under cornering.

This big one-way check valve makes sure the fuel enters the sump quickly from the bottom of the tank and doesn’t come out of it.  The return line also empties into the sump to help keep it full.

Next, we will get the plumbing for the second pump plugged in.  First, the Allen plug blocking the flow to the fuel manifold is removed.

Then this barbed fitting is installed.  This is for the feed from the second pump.


  1. While it was not explicitly stated in your article, ensure you are using correct heat shrink for anything submersible. Stuff like Raychem DR25 is not ethanol/methanol safe.

  2. I like the idea and intension of the catch tank part, find it a bit small comparing to the double 340l/h pumps. On this size ist empty in les than 3 sec acceleration.
    Have you measured the restriction of the 7mm fuel lines with the two pumps tunning at idle? Normally with one pump at idle you increase it by 0.6-0.8bar at the pump compared to the fuel rail.
    Also the oem wiring was made for 6-8Amp pumps, these with the increased pressure are sucking on boost about double making 2volt drop in voltadge so loosing about 30% flow and heating the wire.

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