DeatschWerks DW400 Pump Module & Kits for RSX, Civic

DeatschWerks DW400 Fuel Pump Module - 02-06 Acura RSX (DC5) / 01-05 Honda Civic

Turbo kits for the RSX and EP3 have been around for twenty years, and most of them end up running into the same problem: fuel. Both cars run a returnless fuel system. The pump, filter, and pressure regulator all sit together in the tank module, and pressure gets set there before the fuel goes up a single line to the rail. That's simple and clean for an N/A K20, but the pressure can't change with boost. As boost climbs, the pressure in the intake manifold pushes back against the injectors, and they deliver less fuel than the tune expects. The factory pump also has very little headroom past stock power. Put both problems together, and a boosted K20 can lean out at the top of the rev range, right when it can least afford it.

The DW400 module replaces the factory module and turns the car into a return-style system. A new -6AN line feeds the engine, and the factory feed line becomes the return. With the regulator up in the engine bay and referenced to boost, fuel pressure rises with boost and the injectors keep flowing what the tune asks for. DeatschWerks rates it for 900 hp on gasoline and 700 hp on E85, which is far more than any K20 build needs. Is your RSX stock and just needs a new pump? This module is more than the job calls for. A direct-replacement pump that keeps the factory returnless setup is simpler and costs less.

Factory Features It Keeps

It plugs into your factory harness connector, so you don't have to splice anything. The fuel level sender comes over from the factory module, so the gauge keeps working. The surge bucket stays too. That's the reservoir around the pump inlet that holds fuel at the pickup when the tank's low and the car's leaning in a long corner. It's rated for pump gas, race fuel, and E85.

CPE or PTFE Return Kit

Both return kits come with stainless braided lines and everything you need for the install: hoses, clamps, filters, and electrical connectors. The difference is the hose inside the braid. The CPE kit uses CPE, a synthetic rubber made to handle gasoline and ethanol, and it's the more affordable way to plumb the return. The PTFE kit uses PTFE-lined hose with push-to-fit connections. PTFE doesn't break down in ethanol, and it lets almost no fuel vapor through, so you won't get that fuel smell in the garage. The push-to-fit ends also make the install quicker. For a car on E85 full time, go PTFE.

Install Notes

Run the tank low, then relieve fuel pressure before you pull the module. On the RSX and Civic, you get to it under the rear seat. Use a new module-to-tank seal if the old one is hard or flattened. Route the -6AN feed away from the exhaust and anything that moves, and secure it along the body. Check for leaks with the key on and the pump running before you start the engine. Check the voltage at the pump connector with the engine running. A dedicated relay and new wiring will fix it if it's low. Get the car tuned for the new fuel pressure before you add boost.

Fitment

• 2002-2006 Acura RSX Base and Type S (DC5) - K20A2, K20A3, K20Z1
• 2001-2005 Honda Civic - confirm your body style and trim before ordering
• Converts to a return-style fuel system: -6AN feed, factory feed line reused as return