A. A 15 PSI Hobbs pressure switch and interface harness are included with the system as standard equipment. 15PSI is the best pressure at which to activate the secondary fuel pump in most Turbo Buicks. Ideally the secondary pump should be activated approximately 100HP shy of the primary pump running out of fuel to prevent pressure spikes or lean conditions. We recommend using either your computer or our Hobbs switch to control the secondary pump. This reduces the electrical load, fuel heating and wear on the secondary pump.

A. This hanger can accommodate any 38mm body pump such as an RXP-255E2, RXP-340E2, F90000274 or F90000285 pump in single or dual configuration. Currently we offer this system with any of these four pump variations in a dual configuration. NOTE: WE DO NOT ACCEPT CUSTOMER-SUPPLIED PUMPS TO BE INCORPORATED INTO OUR DP SYSTEM PERIOD!

A. The DPFS-G7900 DP hanger uses Walbro F90000274 pumps which are 100% Ethanol compatible. True E85 factory certified systems have their electrical connections fully isolated from the fuel which is impossible given the Turbo Buick's tank design. Modern E85 Flex-Fuel systems are manufactured with special plastics and metals. Fuel system health will impact pump life.

A. Running dual high-output pumps full-time creates excessive fuel heating through mechanical work and amperage draw. Staging ensures high volume is available instantly under load while keeping fuel temperatures stable during cruising.

A. Racetronix generally advises against voltage boosters when using E85. The F90000274 pumps feature high-amperage internal components; increasing voltage beyond 15V significantly accelerates commutator wear in alcohol fuels. Our 10-gauge harness is engineered to provide maximum battery voltage without these risks.

A. Standard seals experience "swell-and-crush" failure when exposed to race fuels. Our proprietary FVMQ (Fluorosilicone) seals maintain dimensional stability, ensuring electrical pins remain sealed against vapors, preventing terminal corrosion and heat failure.

A. The DPFS-G7900 incorporates an integrated Racetronix venturi manifold. This uses a portion of the returned fuel flow to create a low-pressure siphon, drawing fuel from the tank into the reservoir to keep the pumps submerged even during high-G cornering.

A. High-performance turbine pumps are highly sensitive to microscopic debris. A 10-micron stainless steel element (Part No. FEM-1210) is required downstream to protect injectors. This element is used inside our FILTER-1212B housing. This exact combination is standard equipment in our FLK-G7X series Buick fuel line kits to ensure system protection and consistent spray patterns.

A. To ensure the regulator functions within its linear range and to prevent pressure creep, a -8AN Feed and -6AN Return line is the absolute minimum requirement. For maximum stability at 1000HP+, a -8AN Return is highly recommended.

A. Racetronix REG-G7B1 (factory location / best option) or Racetronix REG-FI886BS universal with aftermarket fuel rail configurations.

A. Only if the return system is restricted. By using the recommended -6AN or -8AN return lines and a Racetronix high-flow regulator, the volume of fuel returned at idle can be processed without artificial pressure buildup.

A. These are the typical test bench specs with 2 x F90000274 Walbro 450 pumps using stodart solvent @ 20°C:
• 890 LPH @ 43.5psi @ 14.0v @ 32.5A
• 1042 LPH @ 43.5psi @ 16.0v @ 36.5A
• 720 LPH @ 80.0psi @ 14.0v @ 38.9A
• 864 LPH @ 80.0psi @ 16.0v @ 43.3A

A. These are turbine-style pumps, which are significantly quieter and exhibit much less vibration than older gerotor or external roller-vane designs. When submerged in the tank, they are barely audible.

A. Yes. The F90000274 450 LPH pumps in this system are a very robust choice. However, if your power requirements increase, you can upgrade to the Walbro F90000285 525 (Hellcat) pumps. The wiring and fuel hanger infrastructure in this 900 system are fully capable of supporting that upgrade path.

A. Older line kits utilizing 45° JIC fittings are not directly compatible due to tight port spacing. Customers can adapt these kits by replacing the heads with straight male ORB fittings. For the -6 return side, use part FIT-680706. For the -8 feed side, use part FIT-680708.

A. High-flow pumps draw significant current. Standard 4-way connectors often overheat when pins are shared or overloaded. The Racetronix 6-way bulkhead provides isolated, high-amperage paths for each pump and the level sender, ensuring long-term terminal integrity.

A. Ceramic provides superior thermal stability and wear resistance compared to standard plastic or fiberglass cards. This ensures the fuel level signal remains accurate and consistent over the entire life of the vehicle.

A. You can build a custom setup using JIC (commonly termed AN) female hose and fittings. We offer the required ORB-to-JIC adapters under the **add-ons** at the bottom of the page. For a -8 feed line, use part ADF-495104 (-10 ORB male to -8 JIC male). For a -6 return line, use part ADF-495100 (-6 ORB male to -6 JIC male). However, for the most reliable installation, we highly recommend our FLK-G7B5 fuel line kit. This kit provides a complete **plug-in-place** solution using high-quality ORB fittings that connect directly to the hanger, removing the need for extra adapters. Regardless of the manufacturer, we strongly recommend steering clear of rubber-lined (CPE) hose. The only viable long-term solution is **PTFE (Teflon) hose**. Racetronix kits utilize American-made, static-dissipative PTFE hose for maximum safety and longevity.

A. No. Racetronix does not provide or sell individual components of the DPFS-G7900 system (such as the hanger assembly, pumps, or harness) for the purpose of DIY applications. We maintain strict system integrity to ensure performance and reliability. However, we do supply replacement or repair parts to customers who have previously purchased a complete system, provided they can supply a valid serial number and invoice for verification.