1. Is the 12-bolt mounting pattern standard?

A: Yes, it is fully compatible with Racetronix 5/10/15 gallon cells. A dimensional template is provided below for custom-fabricated tanks.

2. How do I ensure the module fits my specific tank depth?

A: Provide your tank depth, and Racetronix will custom-cut the support rod at no additional charge for optimal placement.

3. How secure is the vapor seal for interior mounting?

A: Total vapor containment is achieved via no-grommet seals, O-ring sealed fill caps, and fluorosilicone electrical seals.

4. Can I run a mix of different pump sizes?

A: Yes. The modular design supports mixing RXP turbine or DCSS turbine pumps for staged configurations.

5. Should I run all four pumps at the same time?

A: No. We recommend sequential activation via pressure switches or Ground Control Loops to reduce heat and power draw.

6. Does the module include a fuel level sensor?

A: No. The bracket is an optional add-on. We review compatibility with your gauge cluster and resistance range directly.

7. What size fuel lines and regulator should I use?

A: A -8AN PTFE feed is minimum. For quad-pump configurations, a -10AN or -12AN PTFE feed is recommended. The ORB-10 manifold discharge ID is closer to a -12 hose, making our specific fittings ideal for high flow.

8. Should I use the Walbro 535L (F90000295) in this module?

A: No. Lack of an internal check valve will cause fuel to backflow when other pumps are active. We recommend the 525L (F90000285) instead.

9. What are the electrical requirements for a quad-pump system?

A: At 13.5V, draw can be 80–90A. On 16V systems, it can exceed 110A. Ensure all wiring and relays are sized accordingly.

10. What alternator is recommended?

A: We highly recommend Mechman alternators for superior current output and voltage stability in high-performance racing environments.

11. Which Racetronix harnesses and switches are recommended?

A: We offer three heavy-duty harnesses: UDPH-005 (Double), UTPH-3P (Triple), and UQPH-4P (Quad). Use our Interface Harnesses and Pressure Switches for sequential staging.

12. What is the 100 HP transitional rule for staged pump systems?

A: To ensure a seamless transition, Racetronix recommends a **100 HP transitional overlap** as the absolute minimum. In high-horsepower applications with **rapid boost ramps**, this buffer should be increased to account for the pump's **mechanical ramp-up time**. Activating a secondary pump too late results in a **lean condition (under-fueling)**. Activating it too early can cause a **momentary pressure surge (over-fueling)**. Staging with an appropriate buffer ensures pressure remains constant before the engine demands the extra volume.

13. What is the "Quad Intermediate Harness" and why is it required?

A: The IQPH-C6 Intermediate Harness is the critical link between the fuel cell module and our heavy-duty relay harnesses. Because of the pin count limitation in the 6-position Apex 2.8 bulkhead, the four 10-gauge ground wires are bonded to a heavy-duty ring terminal that bolts directly to the bronze grounding stud on top of the hat. Once grounded, these wires root back into the harness loom and exit through a 10-position Apex connector at the opposite end, ensuring a fully integrated power and ground circuit. It also features a GT280 Metri-Pack breakout for level sensor integration and a universal positive trigger wire.

14. If I start with two pumps, do I need to change this harness when I upgrade to four?

A: No. The IQPH-C6 is fully populated to support four pumps from day one. Even if you are currently only using a double relay harness, the intermediate harness is ready for an upgrade. You can add more pumps or swap to a larger relay harness later without touching the wiring on top of the fuel cell, providing a simple, modular upgrade path.

15. How does the trigger logic work for staging multiple pumps?

A: Our system uses a **Gray Positive Trigger Wire** to supply power to all relays simultaneously (typically triggered by the primary fuel pump output from your PCM). Staging is managed via **Ground-Side Control**:

• Primary Pump: The Ground Control Jumper remains plugged in, providing a constant ground so the pump runs as soon as the PCM sends the positive signal.
• Auxiliary Pumps: These Ground Control Jumpers are removed, and the ground side is interfaced with auxiliary PCM outputs or pressure switches for sequential activation.

WARNING: Do not operate the vehicle with all ground jumpers installed for normal use. This creates excessive current draw and introduces a tremendous thermal load into the fuel. All-jumpers-in is for individual circuit testing or emergency bypass only.

16. Can I swap which pump is the "Primary" unit or use a dedicated backup?

A: **Yes.** By moving the Ground Control Jumper to a different circuit's connector, you instantly designate that pump as the primary unit. This allows you to rotate the primary designation for **even runtime** across all pumps. Furthermore, you can equip a "backup" pump that is pre-plumbed and pre-wired but inactive. If a primary pump fails, you can move the Ground Control Jumper to the backup circuit to restore fuel flow instantly—a massive fail-safe for endurance racing and "drag-n-drive" events.