SiriMoto E85 Ethanol Flex Fuel Sensor Kit for 2021 Honda Civic (2022)

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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.

What is a Flex Fuel Kit in simple terms? It is basically a special sensor installed along one of your fuel lines that reads the amount of ethanol in your fuel, produces a signal, and sends a processed version of that signal to your ECU for use by your tuning device. Combined with a tuning device, it converts your Honda Civic to run on higher concentrations of ethanol (like E85) than is in standard pump gas.

(Video) My Experience Running On E85 | SIRIMOTO FLEXFUEL REVIEW

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. 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.
  • 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 SiriMoto's 1 Year Limited Warranty.
  • 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!
  • Gains of 65+ hp and 70+ lb-ft of torque with just a Hondata basemap!
    • 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.
  • Gains of 60+ hp and 60+ lb-ft of torque with just a Hondata basemap!
    • Available Base Calibrations will provide an increase in power/torque as ethanol content increases, providing peak performance at 50~70% ethanol (E50 to E70) concentrations.
  • 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.
  • 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:
    • Fit 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.
  • 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.
  • Base Calibration Settings available for vehicles using the SiriMoto Flex Fuel Kit and SiriMoto EV14 Injectors.
  • Optional SiriMoto EV14 550cc Injectors:
    • Fit Stock RBC and aftermarket K20 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.
  • 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.
  • Gains of 50-60+ hp and 100-120+ lb-ft of torque with just a Hondata basemap!
    • Available Base Calibrations will provide an increase in power/torque as ethanol content increases, providing peak performance at ~40% ethanol (E40) concentrations.
  • Capable of supporting 340+ whp with upgrades and custom tune.
  • Above E50, boost will be reduced to stay within the limits of the fuel pump.
  • Works with both automatic and manual transmissions.
  • Compatible with both Hondata FlashPro and KTuner.

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.

(Video) REVIEWING The FLEX FUEL KIT From Sirimoto | 10th Gen Civic Si

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).

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, up to a certain extent. 30-50% ethanol is a typical range for maximum performance and efficiency.

Q: Ok, so what do I need to buy?
A: All you need is this SiriMoto Flex Fuel Kit and a red (Race) Hondata FlashPro (or similar tuning solution), 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 a custom tune, you will find that you will not see much power gains going over 30-50% 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 a bit more E85 for any given power level, so your engine and turbo will operate cooler.

(Video) Quick install!! PRL Flex Fuel kit..! 10th gen civic si🌽🌽

Installation Info: This product requires a Race Hondata FlashPro. 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 also need access to E85 fuel.

Ethanol Sensor Info: Direction of flow and orientation of the sensor is not critical. Also, the sensor can be installed on the fuel feed (pressure) side but is not recommended it be subjected to over 100 PSI of pressure. Plumbing the sensor to the return line is possible as well, but not always necessary as the sensor can flow enough fuel for 500+ hp.

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.

Featured Supported Door Configuration:
Honda Civic 4 Door Hatchback , Honda Civic 4 Door Sedan

SiriMoto E85 Ethanol Flex Fuel Sensor Kit supported 2021 Honda Civic Trim Levels:
EX 1.5L Turbo , EXL , LX 1.5L Turbo , Sport 1.5L Turbo , Sport Touring , FK8 Type R , FK8 Type R Limited , Touring

(Video) FLEXFUEL KIT INSTALL ON MY 9TH GEN SI! E85!

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(Video) PRL Motorsports 10th Gen Honda Civic Flex Fuel Kit Fitting Install

FAQs

CAN 2021 Honda Civic take E85? ›

Honda engines are not currently certified or designed to run on E85 or any other alternative fuel.

Can you run E85 without a flex fuel sensor? ›

It isn't absolutely necessary, but if you have a tune for 91/93 pump and a tune for E85, you will need to run the tank to almost empty for either to work alone without a flex fuel kit.

Where should I put my E85 sensor? ›

Where does a flex fuel sensor go? Flex fuel sensors are traditionally placed on the feed line of a fuel system (line going into the engine or the pressure side). This allows consistent sampling of real fuel to pass through the sensor for accurate reading of the fuel.

What is E85 flex fuel sensor? ›

The flex fuel sensor measures the ethanol-gasoline ratio of the fuel being used in a flexible fuel vehicle. Flexible fuel vehicles can be operated with a blend of ethanol and gasoline, up to 85 percent ethanol.

What is flex fuel for Honda Civic? ›

Flex-Fuel systems utilize an ethanol content analyzer to determine the amount of ethanol in a fuel system and a converter to send this reading to the vehicle's ECU to instantaneously adjust for varying fuel mixtures.

What happens if I accidentally put flex fuel in my car? ›

Continually filling a standard gasoline car with this high-ethanol fuel can result in serious fuel system corrosion. Plus, when you accidentally put E85 fuel in a car, it may void your engine warranty. That means you could be on the hook for the repairs, even if your car is brand new.

Do you need an ethanol sensor to run E85? ›

With Flex Fuel technology you can now switch from standard gasoline to E85 fuel, or any mix of the two, on the fly without the need for monitoring your ethanol content or having to store and flash multiple tunes.

What happens if you run E85 without a tune? ›

Unless you're running over 15 PSI of boost, ethanol does nothing for you and also can damage the fuel pump and certain other items that are degraded by exposure to ethanol content above 15%. Lastly, ethanol is hygroscopic (it attracts and is soluble with water), so it can introduce water into your fuel system.

Can I install flex fuel kit without a tune? ›

Registered. Yes. You're able to hook up the fuel lines and run everything, but you can't hook up the power wire. If you do, you'll get secondary air pump codes.

What does an ethanol sensor do? ›

The Ethanol Sensor can be used to measure the concentration of ethanol in air above an aqueous sample. This sensor can be used in a wide range of tests and experiments.

Are flex fuel sensors directional? ›

The sensor may be installed in any orientation; the direction of flow through the sensor does not matter.

What is the octane of E85? ›

What is the octane rating of E85 compared to gasoline? E85 has an octane rating ranging from 100-105, making it a high performance fuel. In comparison, regular unleaded gasoline has an octane rating of 87.

Is E85 and flex fuel the same thing? ›

E85 (or flex fuel) is a term that refers to high-level ethanol-gasoline blends containing 51% to 83% ethanol, depending on geography and season (see Fuel Properties and E85 Flex Fuel Specification).

How do you test a E85 sensor? ›

E85 flex fuel sensor testing - YouTube

What is the difference between E85 and flex fuel? ›

E85 gas (also known as flex fuel) is a high-level combination of ethanol and gasoline that consists of 51 percent to 83 percent ethanol blended with gasoline. The percentage of ethanol depends on the geographical location and time of the year.

Can I put premium gas in my Honda Civic? ›

Can you put premium gas in a Honda Civic? Technically, yes. But many vehicles have engines which are designed to withstand a certain amount of wear and tear. So, for most vehicles, choosing premium gasoline won't make much of a difference.

Does Honda have FlexFuel? ›

Honda offers the following vehicles in the Brazilian market under the label "Flex". These vehicles, including the motorcycles, are capable of running on any blend from E20-E25 to E100. See also Honda's Brazilian flex-fuel vehicles.

Do Hondas need premium gas? ›

When it comes to filling up your tank, most Honda vehicles are going to perform just fine with regular grade gas. Let's take a look at what premium gas actually is, as well as some other things that you might find useful.

Does E85 ruin your engine? ›

E85 is actually safer for your engine than regular gasoline is. E85 flex fuel not only powers your engine but also cleans your engine, fuel lines, and fuel injectors. That's because E85 contains a high amount of ethanol, up to 83%. Ethanol is an excellent cleaner.

What happens if you mix E85 and regular gas? ›

Mixing E85 with high-octane gas is no problem. What is this? There will be a changeover period where your engine will get a lower octane rating if you've been using exclusively gasoline to power your vehicle. Still, other than that, it's perfectly ok to use a mix of E85 and other types of gasoline.

Is it OK to mix flex-fuel with regular gas? ›

Using any octane level of gasoline in a flex-fuel vehicle is acceptable. The sensors in an FFV detect whether the fuel is pure gasoline or 85% ethanol and make necessary changes for optimal fuel injection and timing of combustion. Putting E85 in a car not designed for flexible fuel can be harmful.

Can you run E85 all the time? ›

Because ethanol attracts water it can create rust and seal breakage over time, and if E85 is left in the fuel tank for long periods it can attract more water vapor and potentially cause engine damage.

How much horsepower does E85 add? ›

The benefits of E85 really come from the higher octane (up to 110, depending on ethanol content and quality). This allows some of the same benefits you see when using methanol injection, meaning you can run more spark (if needed) or boost. This normally translates to 25-50 or more horsepower on a forced-induction car.

Can I run E85 on stock injectors? ›

you will not be able to run ethanol on the stock injectors without risk.

Is it better to use E85 or regular gas? ›

E85 has higher octane than regular gasoline. This means that E85 is a lot better for your car's engine than regular gasoline. It is also a cleaner fuel with lesser harmful emissions. On the downside, E85 burns faster and produces lesser energy than gasoline.

Can you mix E85 and 87? ›

Shouldn't be a problem. The computer will adjust for anything up to 85% ethanol. Most regular gas has about 10% or more ethanol in it to begin with, and mixing the two will only result in an ethanol content somewhere between 10% and 85%.

Will a flex fuel kit void warranty? ›

"They'll void your factory warranty for using E15,E20 and E85 fuel blends."

How much is a flex fuel tune? ›

$600-700 sounds about right.

Can you mix 93 and E85? ›

Simply put, if you mix 5 gallons of 91 octane pump gas with 5 gallons of E85, you get 10 gallons of a 96-octane fuel that's very close to E50, or 50-percent ethanol and 50-percent gasoline. (If we're being pedantic, it actually computes to E48.)

Can a 2019 Honda Civic use E85? ›

Btw, what the tuners found is that the 17-19 Civic comes with e85 compliant fuel lines from the factory. Yes, the fuel lines are marked/labeled for e85 consumption. Honda is apparently using many of the same components in the US Civics, as they are with units sold in Brazil that are configured for e85.

What cars can take E85? ›

Drivetrain: 4WD
VehicleFuel Type
Chevrolet Silverado 4WD 2021Ethanol (E85)
Chevrolet Silverado 4WD 2022Ethanol (E85)
Ford Explorer AWD FFV 2021Ethanol (E85)
Ford Explorer AWD FFV 2022Ethanol (E85)
21 more rows

Can you run full E85? ›

What's needed to run Full E85 on the B58? - YouTube

Is Honda Fit a flex fuel vehicle? ›

As specified, the Fit has regular unleaded gasoline with an octane rating of 87 recommended.

What gas is best for Honda Civic? ›

What Kind of Gas Does the Honda Civic Use? It is recommended that you use unleaded gasoline of 91 octane or higher in your Honda Civic. Honda also recommends that you use TOP TIER Detergent Gasoline where available. You should avoid gasoline containing more than 15% ethanol, and NEVER use gasoline containing methanol.

Can I put premium gas in my Honda Civic? ›

Can you put premium gas in a Honda Civic? Technically, yes. But many vehicles have engines which are designed to withstand a certain amount of wear and tear. So, for most vehicles, choosing premium gasoline won't make much of a difference.

Can Honda Civic use E15? ›

The EPA said E15 can be used in any vehicle from 2001 or newer.

Will E85 damage my engine? ›

E85 is actually safer for your engine than regular gasoline is. E85 flex fuel not only powers your engine but also cleans your engine, fuel lines, and fuel injectors. That's because E85 contains a high amount of ethanol, up to 83%. Ethanol is an excellent cleaner.

Can I mix E85 and regular gas? ›

It's perfectly safe to mix E85 with regular gas so long as you have a flex-fuel vehicle designed to handle fuel with high levels of ethanol. We'll discuss a few things to remember when discussing the differences between e85 and regular gasoline later in this article.

What is the octane of E85? ›

What is the octane rating of E85 compared to gasoline? E85 has an octane rating ranging from 100-105, making it a high performance fuel. In comparison, regular unleaded gasoline has an octane rating of 87.

What do I need to run E85? ›

Fuel System Requirements
  1. Fuel lines and hoses, especially inside the tank.
  2. O-rings and seals in the injectors, filters, couplings, and sending unit.
  3. Fuel Pressure Regulator.
  4. Fuel Filters, Stainless mesh filters are best.
  5. The Fuel Injectors and The Fuel Pump need to be compatible with E85 and sized to deliver more fuel.
5 Nov 2019

Can Honda Civic take unleaded 88? ›

Use of unleaded gasoline of 87 octane or higher is recommended. Use of unleaded gasoline of 91 octane or higher is recommended. Honda recommends Top Tier detergent gasoline where available. Do NOT use gasoline containing more than 15% ethanol.

Is it better to use E85 or regular gas? ›

E85 has higher octane than regular gasoline. This means that E85 is a lot better for your car's engine than regular gasoline. It is also a cleaner fuel with lesser harmful emissions. On the downside, E85 burns faster and produces lesser energy than gasoline.

Does flex-fuel burn faster? ›

E85 also burns faster than regular gasoline because it vaporizes faster. So your engine may eat through E85 faster than regular gasoline.

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