FL5 / DE5 Fueling Guide: HPFP, Injectors & LPFP Upgrades for Turbo Builds
By Thomas Germano
Upgrading the turbo on your FL5 Civic Type R or DE5 Integra Type S without addressing fueling is simply leaving power on the table.
As airflow increases, fuel demand follows. On the K20C1 platform, rail pressure stability is the difference between a clean high-horsepower pull and a melted piston.
Why Fueling Upgrades Are Non-Negotiable
The factory K20C1 direct injection system operates around 200 bar (2900 psi). Once you install a hybrid turbo like the 27WON Kuro or step into a full big-turbo setup, the stock fuel system begins reaching its ceiling.
• Rail pressure drop at high RPM
• Timing pull under heavy load
• Boost taper (ECU protecting the engine)
• Reduced long-term reliability
Yes, you can “run” a turbo on stock fueling conservatively. But that’s not optimizing it. If you paid for airflow, you should support it properly.
Stop being cheap. Do it right the first time.
Fueling Upgrade Comparison (2026 Snapshot)
| Component | Brand | Highlights | Price | Best For |
|---|---|---|---|---|
| HPFP | Full-Race |
+68% flow vs stock (4mm lobe) Includes stainless high-pressure line 830whp gas / 700whp E85 rated |
$1,999 | Max effort builds |
| HPFP | XDI EVO |
1.39cc/rev (+36%) 250 bar rating |
~$1,399 | Hybrid daily builds |
| HPFP | XDI HPFP60 |
1.66cc/rev (+63%) 260 bar rating |
~$2,299+ | High boost ethanol |
| Injectors | Hondata 1530cc |
+47% flow 550+ HP tested on E85 |
$1,500 | Most hybrid builds |
| Injectors | XDI 2000cc |
+80% over OEM Custom tuning required |
~$1,399 | 600+ WHP builds |
| LPFP | Hondata In-Tank |
205 LPH rated Designed for 500+ HP flex builds |
$250 | Drop-in reliability |
| LPFP | DW300C |
340 LPH compact pump Requires correct install |
~$189 | High HP setups |
High-Pressure Fuel Pump (HPFP)
Full-Race HPFP
Currently the highest capacity bolt-on option that does not require a 5mm cam lobe.
- 68% more fuel than stock
- Integrated stainless high-pressure line (no drilling)
- Supports serious power
- Hondata tuning integration
Buy once, cry once solution.
XDI Options
- EVO: +36% flow
- HPFP60: +63% flow
Strong options depending on budget and goals.
The 5/64" Fuel Line Restriction
The factory high-pressure line contains an internal orifice that becomes restrictive.
Option 1: Drill to 5/64"
Effective, but contamination risk is real. Cleanliness is critical.
Option 2: Replace the Line
Full-Race includes a new stainless line. No drilling. Cleaner. Safer.
Injector Upgrades
Hondata 1530cc
Excellent balance of power and drivability.
XDI 2000cc
For serious 600+ WHP goals. Requires proper tuning.
Low-Pressure Fuel Pump (LPFP)
As ethanol content and boost increase, the in-tank pump can become the next bottleneck.
Always verify in logs. If DI fuel pressure drops under load, you need more supply.