Calling all Tuners

Dear Tuners & Builders,

You’ve seen it all: from gimmicky signal modifiers to tacky light-up capacitors, there is no shortage of parts that promise results but deliver no tangible performance improvements and/or sketchy reliability. As a tuner or builder, it’s your responsibility to support products that deliver performance, reliability, and safety for your customers.

When it comes to E85 fueling, our kits differ from conventional E85 tuning. We get it—in tuning, “different” can be a red flag, often meaning shortcuts were taken (not good!). With eFlexFuel, different simply means different. Our kits are an effective premium solution to add to your toolbox for E85 fueling, so you can continue offering customers nothing but the best.

Tuners & Builders who are new to eFlexFuel: Review this technical article in full with an open mind. If you have not held one of our Control Units and seen its capabilities firsthand, you will underestimate its potential.

We do not intend to replace E85-specific ECU tuning, which has its place. Our goal is to offer tuners and builders an additional top-shelf E85 fueling product to complement your customers’ builds and offer the best E85-and-gas experience possible.

Not all customers want to be locked into a specific E%, not all customers want to unlock or tune their ECU, and not all customers want to think about changing maps or measuring E% at the pumps: our kit is a solution that allows drivers to grab the E85 handle when it’s available and grab the gasoline nozzle when E85 is not. Please explore below and reach out with any questions!

Sincerely,
The R&D Team at eFlexFuel

Now let’s cut through the noise and focus on what matters most: real gains, real fueling control, reliability, and real-world flexibility.

First, What eFlexFuel Kits Actually Do (and Don’t Do)

eFlexFuel Kits DO

• Enable the vehicle to operate on E85, gasoline, or any mixture of the two automatically and seamlessly.
• Dynamically extend pulse-width relative to Ethanol percentage of fuel to ensure stoichiometry – the higher the ethanol percentage, the greater the pulse width extension.
• Manage ONLY the ethanol-additional fueling without impacting baseline fueling strategy.
• eFlexPro includes native Load and RPM calculations without tapping into external sensors.
• eFlexPro allows for custom 3D / three axis fuel map adjustments (Example: Load x RPM x Fuel Delivery) allowing you to fine-tune the ethanol-additional fueling and meet target AFR/Lambda for E85 and all intermediate ethanol blends.
• Injector Deadtime / Latency adjustability to ensure smooth operation with larger injectors in low injector duration / load operation.
• Support Bluetooth connectivity with our free eFlexApp smartphone app and eFlexTuner Windows tuning software.
• eFlexPro includes 2x optional 0-5V Analog Inputs to allow for greater precision and control via eFlexTuner.
• Include a 5-Year warranty (with free product registration).

eFlexFuel Kits DO NOT

• Touch the vehicle’s ECU or OBD systems.
• Alter ignition timing or boost control.
• Trigger a CEL / SES light.
• Require any special tuning (large aftermarket injector applications may require slight deadtime adjustment for smooth idle).
• Require any map changes, fuel measurements, or other manual actions from the driver.

Dyno-Proven Gains: No Timing Adjustments or Boost Changes Performed

The Takeaway:

All these gains come from the eFlexFuel system automatically correcting fueling for the precise E85 blend in the tank—not manipulating timing or boost. All these dynos reflect out-of-the-box performance, though optional ethanol AFR tuning to meet target lambdas would likely yield greater performance. When AFR is dialed in, engines extract more from ethanol’s inherent properties: higher octane, faster burn, and cooler operation.

Why Tuners Are Turning to eFlexFuel for E85 Flex Fuel Tuning

1. It Complements, Not Competes

• eFlexPro doesn’t touch the ECU or override your ECU calibrations. Instead, it adds a dynamic, ethanol-aware fueling layer on top of your dialed-in gasoline tune.
• You retain full control over timing, boost, and all the advanced strategies you’re used to—while eFlex handles the ethanol-specific fueling corrections.

2. Injector Size? No Problem.

• eFlexTuner allows precise deadtime/latency adjustments for the ethanol-additional fueling—critical for smooth idle and accurate fueling with large injectors.
• The system operates on percentage-based corrections, so as long as your gasoline tune is solid, eFlexFuel will scale fueling for any injector size, from OEM to 1,500cc+.

3. True Tuning Tools

• 3D Fuel Mapping: Tweak ethanol fueling by RPM, load, blend percentage, or other sensor input—just like you’re used to in other tuning software.
• Wideband Integration: Log AFR directly via 0-5V analog input. Datalog, analyze, and refine with the same rigor as your main tune.
• Autotune (Beta): Log with a wideband, then let eFlexTuner generate a new map with a single click based on real-world lambda data.

4. Fuel-Based Logic, Custom Capabilities

• Not locked to a specific injector size or vehicle. The harness and ethanol sensor adaptors are vehicle-specific, but the control unit and software are universal.
• Works seamlessly on everything from bolt-on street builds to high-horsepower, standalone-managed monsters.

Addressing Tuner Concerns Head-On

“What About Big Injectors?”

• Deadtime Tool: Compensate for injector latency in eFlexTuner. No more rich stumbles or lean spikes at low load.
• Percentage-Based Corrections: Scales with injector size. Baseline pump gas tune must be solid; eFlexFuel handles the rest.

“No timing control? There won’t be any gains.”

• The dyno results speak for themselves. Take another look at the gains from eFlexFuel + E85.
• Timing adjustments can amplify gains in some cases, but they’re not the foundation for improved performance. Proper fueling for dynamic ethanol blends will allow engines to exploit ethanol’s properties without timing changes, including ethanol’s flame propagation rate, charge cooling impact, oxygen content, and octane rating.

“It’s just a piggyback, I can’t trust it on a high-dollar build.”

• eFlexPro is designed for everything from stock vehicles to high-power, highly modified vehicles, with advanced signal processing (VelvetTouch+), optional sensor integration, and detailed mapping. It’s not a generic resistor box—it’s a real-time, data-driven controller built for enthusiasts with the capacity to support tuners who know what they’re doing.

“I need to see the data and make my own maps.”

• eFlexTuner gives you 3D mapping, full datalogging, and analog sensor integration. If you can create custom ECU tunes, you can tune ethanol AFRs with eFlexTuner—without the risk of bricking an ECU or fighting with locked tables.

“What if I’m unsure whether my customer’s fuel system is up to the task of E85?”

• eFlexFuel verifies compatibility for every order. If your customer is running big injectors or a return-style system, just list your mods — we’ll confirm the connectors and flow before shipping. System warnings prevent you from running lean or overdriving injectors.

Strengths and Limitations: Straight Talk

Pro Tuning Workflow: How Tuners Use eFlexFuel in Conjunction with Custom Tuning

1. Dial In Your Custom Gasoline Tune
   Use HP Tuners, Cobb, VFTuner, or your preferred platform. Set timing, boost, and fueling for pump gas.
2. Confirm Fuel System Capacity
   Most factory fuel systems have capacity for eFlexFuel + E85. Confirm this via our B2B portal or vehicle configurator. Large power adders will require larger injectors and often larger fuel pump.
3. Install eFlexPro
   No ECU flashing or OBD interference. The system uses existing sensors and injectors.
4. (Optional) Map Ethanol Fueling
   • Dyno or Street: Adjust 3D maps while monitoring wideband. Immediate results, just like you expect.
   • Wideband Logging: Wire your wideband to the analog input, log, and refine.
   • Autotune (Beta): Let the software build a map from your wideband logs.
5. Customers Enjoy True Flexibility
   Customers can fill up with gasoline, E85, or any blend of the two—no re-flashing, no guesswork.

How It Works: Tuner-Grade Fuel Control

eFlexPro + eFlexTuner: The Tuner’s Edge

• 3D Fuel Mapping: Adjust AFR by RPM, load, analog sensor input, and ethanol content. No locked ECU tables or OBD interference.
• Deadtime Adjustments: Fine-tune injector latency for smooth idle and transitions on high ethanol blends, even with 1,500cc+ injectors.
• Sensor Integration: Wire in wideband O2, MAP, MAF, or TPS for precise tuning. Analog inputs support 0-5V signals.
• Virtual Load Sensor: Map fueling without tapping factory sensors—ideal for builds with standalone ECUs.

Why It’s Not a Basic Piggyback

• Patented eFlexTuner: Full 3D fuel mapping, deadtime adjustment, and comprehensive datalogging.
• Virtual Load Sensor: Enables precise load-based mapping without tapping OEM sensors.
• eFlexApp Integration: Monitor ethanol content, injector duty, temps, and switch between custom drive modes from your smartphone.
• Wide Injector Compatibility: Percentage-based logic and deadtime tools ensure smooth operation with any injector size.
• OEM-Grade Reliability: Finnish-engineered, VelvetTouch+ signal processing, and a 5-year warranty.
• Dynamic Fuel-Based Logic: Corrects pulse width by exact fuel blend and in real-time, not static values.

eFlexFuel: A Tool for E85 Flex-Fuel Performance

If you’re using a pro tuning platform, you already know the power of E85. But you also know the challenges of creating a reliable and honest flex-fuel tune that will automatically adjust for the exact ethanol % in the tank. Sometimes this simply isn’t possible, and most flex fuel kits just don’t offer the control, data, or reliability you demand. That’s where eFlexFuel’s eFlexPro and eFlexTuner step in—giving you the precision fueling layer your customer’s builds deserve, without interfering with your core ECU strategies.