Fuel Pump Assembly
(comes pre-assembled)


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• Walbro (LPE) GRJ420 jet-pump
• Bucket with checkvalve assembly
• Filter sock
• Filter screen
• Upgraded 14 gauge Walbro-GM Teflon harness
• High-pressure non-Kinking fuel tube
• Oetiker clamps
• Silicon pump seal

Plug and Play Wiring Harness
Drain Kit

• Plug & Play (no splicing or crimping required)
• Weatherproof connectors
• Heavy 10 Gauge stranded copper wire
• 40A weatherproof silver-contact relay
• Waterproof fuse holder w/SS hardware
• Alternator-direct hookup for maximum performance
• Silicon grease, spare fuse, wire ties included
• PnP compatible w/ MSD or KB Pump Booster
• Key-off fuel pump power jumper and drainage kit 

Walbro direct-fit HP Gerotor Jet Pump:

The GRJ420 pump is a direct-fit replacement for the factory Walbro jet-pump. Direct-fit means no modification to the fuel module is 
required therefore the full functionality of the fill bucket is maintained. The fill-bucket allows the fuel pump to use its jet + venturi 
function to keep the pump immersed in fuel at all times regardless of the tank fuel level. This aids in preventing fuel starvation under 
hard cornering and acceleration. Keeping the pump immersed in fuel also helps prevent moisture damage which can shorten the pump's life.

GM type no-kink solvent resistant fuel tube:

This fuel tube is the same type used by GM from the factory. The fuel tube is kink-resistant thanks to its ribbed design. Its special composition makes it more resistant to the solvents in today's pump gas (i.e. toluene, Xylene, MTBE, Ethanol) as compared to 
rubber / neoprene which dries out, swells and cracks.

Upgraded 14 gauge Teflon in-tank harness (C5-ITWH):

Racetronix has upgraded the factory Teflon wiring from 16 gauge to 14 gauge silver-plated multi-strand copper wire. This helps 
reduce voltage drop and at the same time maintains the same level of resistance to fuel solvents as the factory wiring. Generic Walbro kits do not use Teflon wire but rather a much less expensive plastic type.

Direct-power pump wiring (no adapters / splices):

The Racetronix in-tank wiring harness is a one-piece assembly. One end has the Walbro connector and the other is fitted with GM type terminals which are installed directly into the factory connector making it true plug & play. Generic wiring harnesses require cutting and splicing of the factory wiring.

Redundant in-tank ground loop (solves factory problem):

The factory in-tank wiring has the ground from the pump and ground from the power connector split into two circuits which relies on push-lock terminals and the module's body as a ground junction source. We have seen these connectors lose and in some cases corroded. If one were to fail the pump would lose power. Racetronix has redesigned the grounding system with a daisy-chain / loop through circuit. This way there are three grounds all tied together thereby making circuit failure almost next to impossible. An extra ground is also provided via the external upgrade harness via a ground lug. This further enhances the fuel module's grounding system and eliminates the chance of a floating ground condition. A floating ground condition will cause a static buildup and potential fuel 
ignition. All harnesses are assembled using our computerized crimp-quality monitoring system and then circuit checked for the utmost in reliability.

Fuel Screen / Silicon gasket seal:

A new replacement filter screen and silicon pump seal are provided

Alternator-direct power for maximum voltage / True PnP with GM type connectors:

The Racetronix PnP upgrade harness provides alternator direct power for maximum pump voltage. Racetronix has documented an 
average 1.2-1.5V increase in pump voltage in the C5 which equates to a 15-18% increase in pump volume based on Walbro's 
specifications and Racetronix field tests. A minor increase in fuel pressure will actually be experienced with the installation of this 
harness. The harness is fully 'plug and play' and is installed without cutting into factory wiring. The entire harness is weatherproof 
made with the same Delphi interconnect components used throughout your C5. The harness' operation is quite simple. The factory 
power wire which was once used to power the fuel pump is used to trigger a 40 amp-rated relay which in turn supplies 
power directly from the alternator with fused protection. The harness is ultra-reliable which is why Racetronix provides a lifetime 
warranty on parts and labor. All harnesses are assembled using our computerized crimp-quality monitoring system and then circuit checked for the utmost in reliability. All wiring is protected by high-temperature-rated Nylon looming.

Redundant grounds = improved voltage & reliability:

A redundant ground is provided which loops into the harness. This loop enhances ground to the factory harness making a two-fold 
improvement. A secondary ground for the fuel module is also provided. This enhances the ground at the pump's source and through the fuel module's body. (see above)

Pump-booster PnP ready:

The Racetronix harness is equipped with an intermediate high-current (30 amp) connector just after the relay. This allows for easy 
plug & play addition of a pump voltage booster which can increase pump performance upwards of 30%. A spare connector 
assembly set is included so that any booster can be adapted to plug into the Racetronix harness. The Racetronix harness further 
enhances pump booster performance by eliminating voltage drop. The heavy 10 gauge power feed is more than capable of 
handling the 15-20 amp loads generated by the pump at boosted voltages.

Fuel Pump Drain & Power System (optional C5-FDK)

A special wiring harness is included with this system which allows the in-tank pump to be powered up without the vehicle running. 
This can be used to help drain much of the fuel from the tank before undergoing replacement of the factory pump or to drain race 
fuel from the tank at the track. Simply install the Racetronix upgrade harness, unplug the intermediate pump booster connector and 
plug this drain harness in. Attach the alligator clip to the back of the alternator + or battery + to supply power. The harness is fused 
for your safety and is assembled with fuel resistant wire. A length of clear vinyl hose with gear clamp is included which is attached to the 
fuel module's 'black' outlet port to aid in draining the tank.

Hardware included:

There is nothing worse than being in the middle of an installation only to find that the manufacturer has skimped on installation hardware. This is why Racetronix supplies a spare ATC fuse, 25 black nylon wire ties, silicon grease and stainless mounting hardware with each kit.

Technical note:

The Racetronix fuel pump in this system is capable of supporting apx. 600RWHP @ 0.5 BSFC @ 58PSI (400KPa) using factory lines. In early model C5's with rail-mounted fuel pressure regulators the above HP support can be achieved. Addition of a pump voltage booster may increase support to apx. 700RWHP. Cars with superchargers, turbos and low battery voltage may see lower HP support numbers. 

Late model C5's with the returnless rail system will not be able to achieve this level of HP support with the fuel system alone.
This is because the point of regulation is at the back of the car. The location of the FPR does not allow it compensate for line 
pressure drop even though the pressure is stable at the back (regulator location). There are two options to get around this problem. 
First is to convert the system to a rail mounted FRP return type (best). The second option is to install a pump booster which is 
activated at the point where rail pressure starts to drop. The boost in fuel volume overwhelms the regulator / return line thereby 
increasing the fuel pressure at the back of the car which translates to higher pressure at the rail. We recommend the MSD unit for 
FI applications as it ramps the voltage based on manifold pressure. This prevents a short but abrupt fuel pressure spike which 
causes the motor to hiccup from brief over-fueling. If you are using an instant-on N2O system then the KB BAP can be considered as well.

Please understand that this is not an issue with the Racetronix system but rather a design limitation of the factory configuration. 

2003 C5 Corvettes can be checked for compatibility with the Racetronix fuel system. If your access port for the fuel module can be seen in front of the driver's side rear tire (under the car) then this system will work. If it is not visible then you have the new type of module which goes in from the top of the tank. The Racetronix system is not compatible with this fuel module / system. If you are not sure please have a qualified person check before ordering your system.

• C5-FPA Fuel Pump Assembly
• C5 Plug & Play Wiring Harness
• PBIC Pump Booster Connector Set (optional)
• Drain system (optional)

• C5-FPA Fuel Pump Assembly

• C5-FPWH Plug & Play Wiring Harness
• PBIC Pump Booster Connector Set (optional)