DIY Dual Pump Kit, 03-13 C5/C6

The DIYDPK-C56 is recommended for factory HP upgrades from 650-1000/1400HP (gas). HP support will vary based on many factors such as fuel pressure, pump voltage, fuel line type/size, motor BSFC etc. Racetronix recommends a 20% safety margin for fuel delivery.

This kit is designed to fit in all C5 Corvettes manufactured 2003 1/2 and later with VIN # 114931 (last six digits) and up as well as all C6 Corvettes through 2013 excluding the ZR1.

IF YOU ARE UNSURE OF YOUR MODULE NUMBER PLEASE E-MAIL US YOUR VIN # BEFORE YOU ORDER. WE CANNOT ALLOW RETURNS ON ANY OPEN BOX PUMPS PERIOD!

DIYDPK-C56 KIT

DPA-510 / DPA-680 Dual Pump Assemblies

For customers who need enough fuel to support upwards of 1,000HP, Racetronix offers the DPA-510 dual in-tank fuel pump assembly with twin RXP255 255LPH fuel pumps. An optional DPA-680 with two Racetronix RXP340 340LPH pumps is available to support upwards of 1400HP. These dual pump assemblies are coupled using our billet dual pump coupler and stainless mounting bracket. The outlet uses 3/8" hose barb that can accommodate both rubber and plastic fuel lines. The billet coupler is fitted with Viton o-rings for a reliable push-fit seal. All components in this assembly simply slip together for simple assembly/disassembly. No clamps are required.

Racetronix Quality Pumps

The Racetronix DPA-510/DPA-680 is based on Racetronix turbine pump technology which provides quiet reliable operation.

Wiring Harness Components

Racetronix wiring solution is made up of three components:

The main power harness maximizes performance and eliminates the potential for factory wiring failures. This is achieved by using 10-gauge TXL wire which is many times heavier than factory, along with quality weather-proof Delphi connectors and Racetronix sealed relays. Each circuit is independent with its own fuse, relay and ground control loop connectors. This harness provides these functions:

• Provides alternator/battery direct power to the rear of the vehicle which eliminates all voltage loss to the pumps and maximizes pump performance.
• It provides two independently fused circuits for proper pump protection and fire prevention.
• It provides two ground control connectors with jumpers allowing user-selectable primary/secondary pump control via the supplied pressure switch or optional (user supplied) control interface (i.e. PCM).

The intermediate harness is used to interface the main power harness, factory chassis harness and fuel module together. This harness provides these functions:

• It allows the fuel level sensor signal to pass from the fuel module through to the PCM.
• It diverts the fuel pump power signal to trigger the relays on the main power harness
• It passes power for the pumps from the main harness into the fuel module's proprietary bulkhead connector.
• It provides a redundant heavy-duty ground for the dual pump assembly.

The in-tank harness features custom Racetronix HD 10-gauge fine-strand Teflon wire which is E85 compatible. The in-tank harness provides these functions:

• It passes power from the fuel module's proprietary bulkhead connector to the fuel pumps
• It provides a connection to the fuel level sensor
• It provides a connection for the module's static grounding system.

The HIH-xxx harness connects the pressure switch to either of the control connectors on the main power harness using PnP weather-proof connectors.

Racetronix HPS heavy-duty industrial pressure switches are water tight and compatible with most solvents / fuels.

Every part of this wiring system is designed to provide maximum performance by maintaining 10-gauge wire from the alternator/battery straight through to the pumps while being entirely weatherproof and plug & play.

FAQ (PRELIMINARY - DATA CURRENTLY BEING ADDED)

Q1. Which DPA assembly do I need 510 or 680LPH?
A1. There are many factors which impact the choice of pump assembly required such as maximum WOT fuel pressure, motor BSFC, target A/F, fuel type etc. This is a very involved topic which is beyond the scope of this faq. There are many on-line articles which cover this technically topic in detail. Please review our RXP255 flow graph and RXP340 flow graph for reference. As a rule we recommend our DPA-510 for applications up to 1000FWHP and our DPA-680 for applications above 1000FWHP (using gas). These are the typical specs of the DPA-680 installed in a module:
680LPH @ 43.5psi @ 13.5v @ 22.5A
820LPH @ 43.5psi @ 16.0v @ 27.5A
635LPH @ 58.0psi @ 13.5v @ 24.5A
790LPH @ 58.0psi @ 16.0v @ 29.5A
550LPH @ 80.0psi @ 13.5v @ 28.0A
710LPH @ 80.0psi @ 16.0v @ 32.5A

Q2. Which pressure switch do I need?
A2. We recommend that the pressure switch be chosen so that the secondary pump turns on approximately 100HP before the primary pump is maxed out. On forced induction cars this typically occurs around 600FWHP for the DPA-510 and around 750FWHP for the DPA-680. Turning the secondary pump on too early will cause a pressure spike and engine over fueling / bog. Turning the secondary pump on too late will cause a lean condition, detonation and engine damage. Bigger is not always better because excessive flow will heat the fuel and draw more power. Always size your pump combination properly. The 4 and 7PSI switches are the most common for V8 engines.

Q3. Do I need to upgrade fuel lines?
A3. The factory fuel lines in the C5/C6 Corvette are good to a point. The biggest problem for high-HP applications is the regulator being located inside the fuel module. While this is good for reducing production costs and emissions it is not for stable fuel pressure at the motor. This is because the regulator has no way to compensate for feed-system pressure drop. We typically recommend adding a front mount regulator and -6 Teflon return hose for all applications that require a dual pump system. This will also reduce the required injector size (ease tuning) assuming the fuel pressure is boost referenced. This will help maintain a constant pressure differential across the injector.

Q4. How do I prepare my fuel system for a front-mounted regulator?
A4. The following items will be required to install a front-mounted regulator and return line.
1. 90-degree -6 bulkhead fitting with seals for the fuel return on top of the pump module
2. A length of -6 Teflon braided hose to run between the regulator's return port (engine compartment and the FPM return bulkhead.
3 A 3/8" Push-loc tee system placed between the fuel rail and feed line.
4. A short length of -6 Teflon hose between the tee system and the regulator's input port.
5. A regulator block off plug to replace the FPM's regulator.
6.A jet-pump regulator bypass for the P/S tank.

Above 1000HP we recommend a -8 Teflon hose to replace the factory feed line as well as -8 fittings being welded to the factory LS2/LS3 rails for better fuel distribution The proper fittings and Push-loc adapters are required.

Q5. Does this kit maintain the jet-pump / venturi functionality of the factory fuel pump module?
A5. Not it does not. The pump assembly displaces too much volume in the factory module to be effective and therefore access ports must be made to ensure proper fuel reaches the high-flow pumps. This requires that a reasonable level of fuel must be maintained to prevent fuel starvation under hard acceleration and cornering..

MORE TO COME SOON