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SiriMoto E85 Flex Fuel Kit for Honda Civic

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Honda Civic
Year Range
Door Config  [Trim Level]
Application / Notes
2012 to 2015
All [Si]
(No Fuel Injectors or Fuel Pump)
2012 to 2015
All [Si]
(No Fuel Injectors) (With Fuel Pump)
2012 to 2015
All [Si]
(With 550cc Fuel Injectors and Fuel Pump)
2012 to 2015
All [Si]
(With 550cc Fuel Injectors) (No Fuel Pump)
2016 to 2018
4 Door Sedan [EXL, EXT, Touring]
2016 to 2020
2 Door Coupe [EX, EXL, EXT, Touring]
2017 to 2019
4 Door Hatchback [FK8 Type R]
(FK8 Type R)
2017 to 2020
2 Door Coupe [Si] &
4 Door Sedan [Si]
2017 to 2020
4 Door Hatchback [All Except FK8 Type R]
2019 to 2020
4 Door Sedan [EX, EXL, Touring]

(free in mainland U.S. only)

SiriMoto E85 Flex Fuel Kit Description

Emissions Warning: This product is not designed for public highway or street use, and is only legal for formally sanctioned race use on a racing vehicle that may never be used on a public highway or street.

TIP: Your gas tank is not required to just have all E85 fuel in it after installing this kit (hence the name Flex Fuel). It can have any combination of E85 and non-E85 gasoline in it. The SiriMoto Kit (along with your tuning device) will automatically adjust on the fly, for your current fuel mixture.

  • Allows you to run E85 fuel and mix it with regular pump gas.
  • Potential for huge power/torque gains
  • Helps to spool a turbo earlier and faster.
  • Allows the engine (and turbo) to operate considerably cooler.
  • Enables the ECU to dynamically adjust your tune, for a given amount of ethanol percentage.
Why this SiriMoto E85 Flex Fuel Kit?
  • Great bang for your buck power adder (especially for boosted/forced-induction vehicles).
  • Easily monitor your E85 / Ethanol-Percentage level with the included Innovate digital gauge.
  • You can choose to run regular gasoline and only pump E85 when you desire more power/torque.
  • This kit was thoroughly tested and designed with very reliable components.
  • Easy to install and features pre-assembled fuel lines to plumb the Ethanol Sensor.
  • Comes with comprehensive installation instructions.
  • Covered by a 1 Year Limited Warranty.
Key Features
  • Includes everything you need for a complete installation.
  • Plug-and-Play (PnP) solution, does not require any splicing of wires.
  • Premium Chasiss Harness constructed with:
    • Tefzel Wiring
    • Deutsch Connector
    • Flame-Retardant Nylon Sleeve
  • Sturdy Ethanol Content Sensor Bracket for lifetime reliability.
  • Includes Gauge Pod to easily mount the Innovate digital gauge.
  • Custom SiriMoto Flex Fuel Badge included with every kit!
10th Gen Civic Type R (FK8) Specs
  • Gains of 65+ hp and 70+ lb-ft of torque with just a Hondata Base Map!
    • Available Base Calibrations will provide peak performance between 25-40% ethanol (E25 to E40) concentrations. This is a general recommendation and your exact optimal ethanol % will vary depending on your other bolt-ons and if you use a custom tune or not.
    • The FlashPro has a specific safety strategy for the Type R: boost will decrease as ethanol concentrations surpass 30% (E30) mixtures.
    • Boost is reduced in this manner because the stock High Pressure Direct Injection Fuel Pump cannot supply the necessary fuel volume for full boost above E30.
  • Only compatible with Hondata FlashPro; KTuner platform does not allow for Flex Fuel Capability as of Fall 2019.
10th Gen Civic L15 (1.5L Turbo) Specs
  • Gains of 60+ hp and 60+ lb-ft of torque with just a Hondata Base Map!
    • Available Base Calibrations will provide an increase in power/torque as ethanol content increases, providing peak performance at ~70% ethanol (E70) concentrations or higher.
  • Capable of supporting 300+ whp with upgrades and custom tune.
    • For custom tunes, E30~E40 fuel mixtures provide the best power and fuel mileage.
  • Compatible with both Hondata FlashPro and KTuner.
  • For vehicles equipped with a CVT transmission, torque gains are limited to ensure reliability.
9th Gen Civic Si Specs
  • Base Calibration available for vehicles using the SiriMoto Flex Fuel Kit and SiriMoto EV14 Injectors.
    • For those with a custom tune, Base Calibration Settings are available upon request.
  • Optional SiriMoto EV14 550cc Injectors:
    • Fits both stock and RBC intake manifolds.
    • Feature Plug and Play (PnP) connectors.
    • Capable of supporting up to 300 hp.
    • Compatible with pump gas and E85.
  • Optional Grams Fuel Pump:
    • Flows 265LPH and capable of supporting 400 hp.
    • Compatible with pump gas and E85.
  • Typical gains of 15~20% in power and torque on boosted applications (5~10% on naturally aspirated engines).
  • Only compatible with Hondata FlashPro; KTuner platform does not allow for Flex Fuel Capability as of Summer 2019.
  • Must use higher flowing fuel injectors; stock injectors do not flow enough fuel to support E85.
  • The stock fuel pump is capable of delivering the necessary fuel flow for naturally aspirated vehicles, but long term use will shorten its life-span due to the corrosive nature of ethanol. For continuous use of E85, an upgraded fuel pump is recommended.
More Details / FAQ
Q: What is E85 and why does it easily give so much more power?
A: E85 is a biofuel composed of up to 85% ethanol. The remaining 15% of the fuel is traditional gasoline. Keep in mind the ethanol percentage can be lower during the winter months in some areas. The ethanol often is made from corn and is the same type of alcohol you would find in hard liquor, with the exception that fuel ethanol is denatured with additives to make it undesirable and harmful to drink.

The main reason E85 allows for some much more power than traditional gasoline is that it has a very high octane rating, usually from around 100 to 105 octane, compared to 91 to 93 octane from normal gasoline. This high octane rating allows E85 to resist engine knock. Engine knock occurs when areas of the air fuel mixture ignite before the should due to excessive heat for the fuel type used. This is bad because it can cause extra stress on the engine, and doesn't make optimal power either. From the factory, a new engine is almost always "knock limited", which means it cannot achieve its maximum design power on normal gasoline due to engine knock occurring. E85 basically eliminates this constraint, allowing the engine to achieve the maximum power possible. This especially applies to engines that are turbocharged from the factory.

One nice side effect of that is that extra E85 fuel will help cool your combustion chamber and turbo, and thus help maintain maximum power and reliability. E85 fuel is also generally a decent amount cheaper than normal pump gas.

Vehicles sold in the U.S. are designed to operate correctly on the factory tune when using fuel that contains between 10% (E10) and 15% (E15) ethanol. E10 is normally found at almost every standard gas pump in the U.S., so you most likely fill up with it all the time. The reason for this is that ethanol has been found to reduce overall emissions while keeping engine performance strong (see https://afdc.energy.gov/fuels/ethanol_benefits.html for more information). One important thing to note is that as the percentage of ethanol in a fuel goes up, the fuel economy goes down.

Q: Why a Flex Fuel kit?
A: The "Flex Fuel" part of this kit refers to the ability to run a varying amount of ethanol without having to re-tune or worry about exactly how much E85 you filled up with. In general, the more you fill up with, the more power you get.

Q: Ok, so what do I need to buy?
A: Amazingly, all you need is this SiriMoto Flex Fuel Kit and a red (race) Hondata FlashPro, along with some E85. This flex fuel kit constantly monitors how much ethanol is in your fuel, displays it for your information on the digital gauge, and then tells the FlashPro. The Hondata FlashPro dynamically recalibrates your ECU to give the optimal power gains on any percentage of ethanol you happen to have in your tank.

Q: Is a custom tune necessary?
A: No, it is not. To get the advertised gains, all you need to do is install this kit, reflash your ECU with the appropriate E85 Hondata FlashPro basemap, and fill up with E85. If you have a CVT transmission, torque gains will be limited to ensure transmission reliability. If you have a manual transmission and want even more power, a custom tune (higher boost and more aggressive timing) combined with other bolt-on parts can easily push you past the advertised gains. Keep in mind that the Hondata FlashPro basemaps are deliberately conservative, designed with maximum reliability in mind. If you get an aggressive custom tune, you will find that you will not see much power gains going over 40-50% or so ethanol in your tank. However, as mentioned, a Hondata basemap will offer better reliability as it is conservative enough to account for sensor inaccuracy and uses more E85 for any given power level, so your engine and turbo will operate cooler.

Q: Where can I get E85?
A: The easiest way is to find E85 stations is by using websites such as getbiofuel.com or e85prices.com, or phone apps like GasBuddy. Also, E85 blend calculator apps can help you easily achieve your target ethanol blend. There are many stations available throughout the United States. Simply fill up your race fuel jug with desired amount and be on your way to better lap times!

Installation Info: The product requires a race Hondata FlashPro, which is the normal version. It will not work with the blue CARB Compliant / Exempt FlashPro. It works with other compatible tuning solutions too (like KTuner), but you might have to adjust the voltage output ranges on the Innovative gauge. To experience the power gains of this product, you will need access to an E85 station, which you can find with websites such as getbiofuel.com or e85prices.com.

Availability and Condition: Unless otherwise noted, this product is in brand new condition and usually in stock at one of our warehouses, or will ship directly from the manufacturer.

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