Fuel Pump Module Assembly, C5/C6 Corvette 2003.5 to 2013 525 LPH E85, External Regulation
Fuel Pump Module Assembly, C5/C6 Corvette 2003.5 to 2013 525 LPH E85, External Regulation
Fuel Module, Corvette C5/C6, E85 Return-Style
Quick Overview
- Extreme Performance: Features a genuine Walbro F90000285 (Slang: 525 LPH / Hellcat) DCSS turbine pump, the highest-flowing in-tank solution for E85 Corvette applications.
- Return Connectivity: Equipped with a -6 ORB/JIC Female bulkhead with a pre-installed 3/8" Male Quick Connect adapter.
- Regulator Block-Off: Internal factory regulator is removed and blocked to allow full unregulated flow to an external regulator.
- MANDATORY WIRING: Requires Racetronix FPWH-008HD and IPH-008 upgrade harnesses.
Optimized Plumbing Integration
Racetronix offers vehicle-specific fuel line kits engineered specifically for the TU475-525R architecture. To ensure a streamlined installation without redundant hardware, we recommend our "R" (Return-Style) and "NR" (No-Rail) series kits:
- "R" Series Kits: Include engine-specific billet fuel rails and the required -8 Feed / -6 Return PTFE lines.
- "NR" Series Kits: Designed for customers who already own billet fuel rails; these provide the complete plumbing loop without redundant costs.
- Bypass Requirement: A REG-BLOCK02 Bypass Plug MUST be installed in the passenger-side tank.
Adjustable Regulator & Cold Start Management
While every Racetronix module is bench-tested for pressure integrity, most aftermarket adjustable external regulators will "bleed down" fuel pressure over time when the engine is off. This is a design characteristic that can lead to a "hard start" condition.
Racetronix Recommendation:
When tuning the vehicle, we recommend extending the Fuel Pump Prime Time in the PCM/ECM settings to 6–10 seconds. This ensures the system is fully repressurized and air is purged prior to cranking.
Critical: Base Fuel Pressure Requirement
This module requires a base fuel pressure of 58 PSI (measured with the vacuum line off/disconnected).
Reducing the base pressure below 58 PSI substantially reduces the efficiency of the jet pump and the passenger-side tank transfer pump, leading to fuel starvation even when the fuel gauge indicates fuel is present.
Mandatory: Level Sensor Selection
To ensure accurate fuel gauge operation, you MUST use the drop-down menu below to select the correct level sensor for your vehicle's model year. Resistance values (Ohms) changed significantly across the C5/C6 production run.
Failure to select the correct sensor will result in incorrect fuel gauge readings.
Technical Specifications
| Effective Flow Rate | ~405 LPH @ 58 PSI (13.5V)* |
| Pump Model | Walbro F90000285 (Slang: 525 LPH / Hellcat) |
| Testing Protocol | Serialized / Bench Tested / Leak-Down Tested |
*Flow Note: This corrected rating accounts for the 58 PSI base pressure and the ~10% parasitic load required to drive both the internal Venturi and the passenger-side tank transfer system.
Estimated HP Support (RWHP)
| Fuel Type | Naturally Aspirated | Forced Induction |
| Gasoline | ~1000 RWHP | ~850 RWHP |
| E85 (Ethanol) | ~700 RWHP | ~600 RWHP |
Frequently Asked Questions
Q: Why isn't the 525R offered with an internal regulator like the 450E?
A: At the high flow rates of the 525LPH turbine, factory-style "deadhead" systems become a liability for three reasons:
1. Pressure Accuracy: A rear regulator cannot "see" the pressure drop across the feed line. Front-mount regulation ensures the injectors see 58 PSI exactly where it matters.
2. Line Restriction: The factory feed line acts as a bottleneck at 525LPH; an upgraded feed line and external regulation are required to unlock the pump's potential.
3. Circulatory Cooling: Unlike a deadhead system where fuel sits and cooks in the rails, this circulatory configuration uses the prime cycle to flush heat-soaked fuel and air bubbles (vapor lock) out of the rails and back to the tank. This provides the engine with cool, liquid fuel for a clean start every time.
Q: Is the HD Hotwire and Intermediate harness really mandatory?
A: Yes. The 525 LPH DCSS turbine draws significantly more current than the factory pump. Running this module on factory wiring will cause massive voltage drop (reducing flow) and will eventually melt your factory connectors or damage the vehicle's fuse center. Racetronix will not warranty a module failed due to improper electrical support.
Q: My car is hard to start after sitting for 30 minutes. Is the pump bad?
A: No. High-performance adjustable regulators do not hold "rest pressure" as effectively as restrictive factory regulators. This is a design trade-off for high flow. Extending your PCM's "Fuel Pump Prime Time" to 6–10 seconds resolves this by allowing the circulatory system to purge air and repressurize before cranking.
Racetronix 1-Year In-House Warranty
Racetronix offers a one-year in-house warranty on this fuel pump assembly from the date of purchase. This warranty is strictly subject to the following terms:
- Harness Requirement: Warranty claims will only be honored if the vehicle is equipped with a Racetronix FPWH-008HD and IPH-008 upgrade harness.
- Professional Installation Required: The module must be installed and diagnosed by a qualified Automotive Specialist/Technician.
- Verification Testing: All returned modules will undergo full bench testing. Warranty is void if failure is caused by improper installation, contaminated fuel, or electrical faults.
C5 Corvette VIN Split: Fits late 2003 C5 Corvettes with VIN # 114931 and higher, and all 2004-2013 C6 Corvettes (Excl. ZR1).
How to Verify Fitment:
- Find your 17-digit VIN.
- Verify at GM Parts Giant or GM Parts Direct.
- Cross-reference via the Delphi Parts Catalog.
*FPWH-008HD and IPH-008 upgrade harnesses are available as add-on options at the bottom of this page.
