Cobb Stage 1 CAN Flex Fuel Power Package – 2018-2021 Subaru WRX

Cobb Stage 1 CAN Flex Fuel Power Package — 2018-2021 Subaru WRX

The Cobb Stage 1 CAN Flex Fuel Power Package for the 2018-2021 Subaru WRX combines the Cobb Accessport V3, the Cobb SF Intake System, and the Cobb CAN Flex Fuel Kit in a single package — the complete Stage 1+ foundation with ethanol capability added. The Accessport CAN Flex Fuel OTS maps dynamically adjust calibration based on the measured ethanol content in the fuel, allowing any blend from 93 octane through E85 without manual map switching.

DETAILS

• Includes: Cobb Accessport V3 + Cobb SF Intake + Cobb CAN Flex Fuel Kit
• Platform: 2018-2021 Subaru WRX FA20DIT
• CAN Flex Fuel: ethanol sensor measures blend in real time — automatic calibration adjustment
• Works with E10 through E85 and any blend in between
• SF Intake: replaces factory airbox for improved airflow at Stage 1+
• OTS maps: 93 octane, E30, E40, E85 — dynamic adjustment based on sensor reading
• NOTE: Ships via UPS/FedEx — signature required at delivery

How Flex Fuel Works on Subaru

Cobb’s CAN Flex Fuel system uses an ethanol content sensor installed in the fuel line to measure the actual ethanol percentage of whatever fuel is in the tank at any given time — whether it is straight pump E85 (typically 70-85% ethanol), E30, E40, any custom blend, or straight 93-octane gasoline. This measurement is sent to the Accessport via the CAN bus, and the Accessport ECU map adjusts fueling, ignition timing, and boost targets automatically based on the real ethanol content — not based on which OTS map slot the driver selects, but based on what the sensor actually reads. This means an owner can run any blend of ethanol and gasoline without switching maps or worrying about whether the current map matches the fuel. The ECU dynamically adjusts for the fuel being used.

CAN System, OTS Maps, and Ethanol Blends

Ethanol provides two performance advantages over gasoline that the flex fuel system exploits. First, ethanol has a much higher effective octane rating than pump gasoline — this allows more aggressive ignition timing advance without risk of detonation. Second, ethanol has a high latent heat of vaporization — it absorbs a significant amount of heat when it evaporates in the intake manifold and combustion chamber, cooling the intake charge and further reducing knock tendency. Together, these properties allow the flex fuel OTS maps to target meaningfully higher boost levels and more aggressive timing than the equivalent 93-octane gasoline maps. The real-world result is a substantial power increase on E30 or higher ethanol blends over what the same engine produces on 93 octane. The flex fuel system makes this power increase accessible without requiring the driver to maintain a specific fuel blend or manually switch calibrations — the system adapts automatically to whatever is in the tank.

What’s in the Box

• Cobb Accessport V3
• Cobb SF Intake System
• Cobb CAN Flex Fuel ethanol sensor kit
• Fuel line fittings and hardware
• OBD-II cable
• USB cable
• 2 faceplates
• Universal mount

Why Choose Cobb Tuning

Cobb Tuning has been developing performance software and hardware for turbocharged enthusiast vehicles since 1999. Founded in Austin, Texas, Cobb built its reputation on the Accessport and expanded into a full catalog of hardware engineered to complement it. Every OTS map is developed in-house on real vehicles, and every hardware product is validated as part of a complete system — not sourced and sold in isolation. That integrated approach is why Cobb produces consistent, reliable results across the builds we see every day.

The RallySport Take

Stage 1 CAN Flex Fuel for the 2018-2021 WRX is the correct package for owners who want Stage 1+ performance with the added capability of running ethanol blends for additional power. The CAN Flex Fuel system removes the need to track fuel blend or manually switch calibrations — fill up with whatever ethanol blend is available, and the Accessport adjusts the calibration automatically. On E30, the flex fuel maps target meaningfully higher boost and more aggressive timing than the 93-octane Stage 1 map, producing a substantial power increase over the gasoline-only Stage 1 configuration.

Fitment

Year	Make	Model	Notes
2018-2021	Subaru	WRX	FA20DIT MT/CVT