Racetronix - C4x Fuel Pump Kit - Kit Configuration Page

Why a Racetronix Fuel System?

The Pump

Walbro 190L/Hr or 255L/hr HP Pump
Filter sock - 30 micron filtering (factory=70 micron)
Walbro to GM direct power wiring (no adapters)
Terminal lock
High pressure fuel line
Stainless gear clamps
Rubber pump mount
Pump sound insulation sleeve
C4 fuel tank gasket
Stainless hex-head tank bolts, washers and o-ring seals ( 9 pieces)
Hex key
Silicone grease

Walbro sets set the industry standard in high-performance in-tank pumps. Walbro pumps are used as factory equipment in performance vehicles such as the C5 Corvette. Walbro's gerotor design is able to maintain high volume at elevated pressures. This is done by squeezing the fuel out between two gears instead of pushing it like most factory vane pumps. The positive displacement gerotor design makes high-performance Walbro pumps small, light weight, quiet, efficient and reliable. Racetronix offers the C44-FPA bundled with the GSS242M 190L/Hr or the GSS340M 255L/Hr pump. The GSS242M is capable of supporting approximately 450RWHP* @ 13.5V through factory lines. The GSS340M is capable of supporting approximately 550RWHP* @ 13.5V through factory lines. (* HP numbers will vary based on engine and driveline efficiency, operating pressure and pump voltage.)

Why do other vendors offer the GSS307M but Racetronix does not? Racetronix has decided to bundle the GSS340M pump with all C44 HP systems as it will do everything the GSS307M will do and more regardless if you are running a naturally aspirated or forced induction motor. Running a high-pressure capable GSS340M pump does not cause abnormally high fuel pressure. Fuel pressure is controlled by the regulator on the fuel rail. The GSS340M's motor design allows it to draw less power than a GSS307M at the same operating pressure. The pressure setting of the GSS340M's internal safety bypass valve is set higher than the GSS307M's to accommodate forced induction applications which require higher fuel pressures than naturally aspirated motors. The Walbro GSS340M is only a few dollars more than the GSS307.

Other vendors state that the GSS340M is a discontinued pump? Walbro introduced the F20000169 pump to replace the GSS340M in March 2004. The F20000169 is exactly the same pump internally as the GSS340(M) apart from the new smaller offset molded inlet. This new inlet design means that Walbro no longer has to machine the ends of a GSS340 pump in order to accept a GM style filter sock. The F20000169 is more expensive than the GSS340M therefore Racetronix will continue to offer the GSS340M while passing the savings along to our customers. Please note the 'M' in GSS340M stands for machined end. A GSS340 (not machined) is the typical pump used in vehicles such as a Mustang and will not accept the GM style filter sock nor fit a G.M. fuel pump module properly. The GSS340 is still a current production Walbro pump.

Pump Installation kit- Racetronix Exclusive!

Walbro does not manufacture a fuel pump installation kit specifically for the C4 Corvette. Walbro's 400-835 and 400-1016 fuel pump installation kits which are normally bundled with the GSS340M and F20000169 pumps are tailored towards 1980's g-body and b-body fuel senders. Racetronix has bundled together a C4 specific fuel pump installation kit which includes a few upgrades such as a sound insulation sleeve, one-piece teflon in-tank wiring harness, C4 tank gasket and stainless sender bolts with o-rings. The factory pump came with a sound insulation sleeve so we have included one. This sleeve helps reduce pump noise heard from outside the tank. Racetronix has manufactured a quality C4 tank gasket and bundled it with new stainless steel tank bolts and o-rings. Most C4 tank gaskets are in pretty bad shape and will not provide a proper vapor seal. The factory black-oxide sender bolts are typically rusted and their o-rings have deteriorated. These bolts must be in good condition and their o-rings intact to achieve a vapor seal as they extend into the gas tank. GM fuel sender gasket (P/N 25091503) lists at $15.25. The fuel sender bolts with o-rings (P/N 14044556) list at $45.54 for a set of nine. A total value of $60.79 included at no extra charge. Racetronix supplied bolts and tank gasket are made from superior materials. A hex key is included to aid in the installation of the stainless sender bolts.

In-tank Wiring - Racetronix Exclusive!

In-tank wiring is quickly becoming a major problem due to the age of the C4's. Many terminals are heavily corroded or rusting off. The generic in-tank wiring adapters supplied with other installation kits rely on the questionable factory wiring and adds another connection to the equation. This translates to more resistance / voltage loss and an extra potential failure point. Racetronix in-house harness manufacturing facility has produced a one-piece replacement for the in-tank pump wiring. Racetronix replacement in-tank wiring plugs directly into the new pump and into the factory bulkhead connector thereby eliminating all the factory pump wiring and the need for in-line plug adapters. The Racetronix harness is made from mil. spec. silver plated 14 gauge Teflon wire vs. the factory's 16 gauge Teflon wire. Teflon is the most resistant to gas and solvents. All connections are assembled using our computerized crimp-quality monitoring system and then circuit checked for the utmost in reliability. There are no wires to cut, crimp or splice. All connections are Plug & Play.

Why use a Racetronix Fuel Pump Upgrade Harness?

Plug & Play (no cutting or splicing required)
Weatherproof factory connectors
Heavy 10 gauge automotive-grade copper wire
Heavy-duty 40 amp weatherproof relay
Weatherproof fuse holder
Alternator-direct power for maximum pump performance
Silicon grease, spare fuse, wire ties included
Stainless steel mounting hardware
Body ground upgrade with battery nuts (optional)
Compatible with various pump boosters (i.e. KB, MSD) (optional)

Factory wiring:

As experienced drivers we all know from observation that there are certain electrical items on our car that when turned on cause the lights to dim, blower motors to slow down and the voltage meter reading on the dash to drop. There are various things that cause this such as battery condition and alternator output but for the most part it is factory wire resistance. In an ideal world car manufacturers would use heavier gauges of wire to reduce resistance in order to prevent voltage drop but that would add much cost, weight and bulk to the harnesses. As a tradeoff car manufacturers try to find a happy medium to satisfy the load requirements for a given circuit in the car without negatively impacting the operation of the device requiring the power at the end of the circuit. The C4's factory fuel pump power circuit was designed to provide power for the light current demands of a factory pump. Typically this circuit is comprised of 16 gauge wiring. Current demands can more than double when a high-performance fuel pump is installed. If we take a step back to high school physics, Ohm's law tells us that when we double the current flowing through a circuit with a fixed resistance the voltage loss across that circuit doubles. The power loss is quadrupled across this circuit which is given off as heat (wasted energy) which can cause electrical contacts (connectors / relays) to heat up and eventually fail. Starving a pump for voltage will cause it to slow down which escalates current demands even more thereby compounding the problem. For those who did not take physics we can consider this scenario... We all know someone who has a high-power car stereo system with heavy power cables running to the amplifier or someone with off-road driving lights using a dedicated circuit with relays. We know what would happen if these amplifiers and lights were hooked up to the same factory circuits which supply the the factory stereo or headlamps! So we pose the question 'how is a high-performance fuel pump any different?' Installing an external fuel pump requires a dedicated power circuit. Just because the factory wiring to your pump is convenient think twice about cramming a 20 amp fuse in panel and consider what you are doing!

The harness:

The factory circuit which supplies the pump is much longer and more complex than many people realize. The circuit looks something like this. Pump connector > in-tank bulkhead connector > external tank connector > relay > fuse box > steering column ignition switch > fusible link > starter solenoid > battery > alternator. Some of these circuits which the fuel pump sources its power from are shared which can compound the voltage drop problems. The Racetronix harness bypasses the entire factory circuit path to provide maximum voltage at all times to your pump. The Racetronix harness uses heavy 10 gauge copper wire to reduce voltage-drop to very low levels so as not to impact pump performance. Our power feed comes off the back of the alternator where voltage is highest. The voltage at the alternator's output is typically 0.5-1.5 volts higher than at the battery voltage depending on the charge current. It then runs through a weatherproof fuse holder and then to the back of the car. The Racetronix harness has connectors which plug inline with the factory harness at the back of the tank. No cutting or splicing is required. High-quality weatherproof fuse holders and relays are used for maximum reliability. The Racetronix harness has a redundant ground upgrade as it is necessary to improve the harness on the negative side of the pump's supply as well. The only function the factory harness serves is to trigger the relay in the Racetronix harness (0.1 amps) and to supply the level sender signal to your dashboard fuel gauge. If the need should arise the Racetronix harness can be unplugged in a matter of minutes. Some people even use this feature to disable the vehicle and prevent theft by C4 savvy joy riders. All current series II Racetronix harnesses are equipped with a 30 amp intermediate power connector just after the relay. This connector allows any aftermarket pump booster (MSD / KB / BW) to simply plug into the Racetronix harness. Adding a pump booster (voltage amplifier) can increase pump output volume by as much as 35-40% when run at apx. 16.5 volts (pressure dependent). An extra connector set is included to be installed on the pump booster's power leads making it a plug & play interface. Racetronix harnesses are considered the best by which all others are judged. Attention to detail in every Racetronix harness is evident at first glance. Racetronix spares no expense to ensure reliability, ease of installation and performance.
All Racetronix harnesses are assembled using our computerized crimp-quality monitoring system and then circuit checked for the utmost in reliability. This Racetronix harness is backed by our limited lifetime warranty.

UPGRADE OPTIONS

BGK
An optional battery to body ground upgrade kit is available (P/N BGK8). This kit upgrades the under-rated factory ground wire running from the battery to the chassis. It includes an 8 gauge copper wire fitted with terminals and battery nuts with accessory taps. We highly recommend this inexpensive option because this is a weak point in these cars.

PBIC
The Racetronix harness comes equipped with an interface connector just after the relay (see product picture above). This connector in combination with an optionally supplied connector set (P/N PBIC) allows for easy plug and play addition of a pump booster / voltage amplifier such as the MSD or KB units. The Racetronix harness comes equipped with an interface connector just after the relay (see product picture above). This connector in combination with an optionally supplied connector set (P/N PBIC) allows for easy plug and play addition of a pump booster / voltage amplifier such as the MSD or KB units. These voltage amplifiers / boosters will allow the Racetronix single in-tank pump system to support an additional 100-200 flywheel HP (B.S.F.C. dependant) when run at 16-17 volts. This configuration offloads the excessive current draw placed on the factory wiring onto the heavy gauge Racetronix harness system. System diagnosis becomes easier by simply being able to unplug, isolate and bypass sections of the wiring system. This configuration offloads the excessive current draw placed on the factory wiring onto the heavy gauge Racetronix harness system. System diagnosis becomes easier by simply being able to unplug, isolate and bypass sections of the wiring system.