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FM Big Flex Fuel Kit (NB)

The kit might vary slightly from this picture.
FM Big Flex Fuel Kit (NB)
Run your Miata on ethanol or gasoline without having to adjust anything - E0 to E100 fuel on the fly!

Exclusive to Flyin' Miata

Availability: In stock



E85 fuel is great stuff. It's basically high octane race gas that you can buy at the pump. You can make a whole bunch of power on it by running a lot of timing - all while bragging that it's green and eco-friendly. Plus it smells nice.

But you need a bunch more of it. This means you'll burn through a tank faster, and it's not always easy to find and can be difficult to start in the cold. The ethanol content of the fuel varies as well - E85 has a maximum of 85% ethanol, but it might have as little as 70%. So we've developed the original bolt-on Flex Fuel Miata system, giving you the ability to put anything from E0 to E100 in your fuel tank.

A  sensor in the fuel system checks the ethanol content and feeds that information to the Hydra Nemesis2.7 . The Hydra will then tailor the fuel and timing delivery automatically to match the exact fuel you're running. The flex fuel capabilities allow seamless interpolation of your fuel, timing, AFR target, start primer & maximum boost maps. This capability is built right into Hydra 2.7 Epsilon - the sensor is even plug-and-play. If you're using a different ECU, please check that your ECU can handle flex fuel.

Because you need higher volumes of fuel with ethanol, we started with the proven hardware in our Big Fuel Kit. Capable of delivering well over 400 hp worth of ethanol fuel, it replaces every piece of your fuel system from the pump to the fuel rail. Since E85 is corrosive, we ensured that the entire system is safe for the new fuel, right down the type of anodizing on the rail. We even include a Flex Fuel badge so there aren't any questions at gas stations. Please contact us to discuss what injector sizes you will need to support your power goals using E85.

The fuel pump is a 300 liter/hour DeatschWerks unit. An adjustable AEM fuel pressure regulator mounted on a custom bracket lets you run either fixed or manifold-referenced pressure. The high-flow filter can be disassembled and cleaned. A -6 (3/8") line allows for lots of volume to the engine - that's about 43% bigger than stock. The fuel rail is FM's own high flow dual feed unit. All the lines are braided stainless steel with AN fittings for a secure connection and easy serviceability. The fuel pressure regulator is mounted in the same location as the stock fuel filter so it's protected and you only have one large line running up to the engine bay. The Flex Fuel sensor is a  part used on factory GM vehicles, so it's engineered to OE lifespans.

All the plumbing fits back where the stock fuel filter used to live. All the components are available separately if you already have some of the parts. All new Hydras come with flex fuel capabilities, it may need to be added to previous units - please contact us with your serial number for details.

Additional Information

Additional Information

Part number 04-46160 NB 1999-05
TÜV approval available No
Fits: 1999, 2000, 2001, 2002, 2003, 2004 (non-MSM), 2005 (non-MSM), MSM
Manufacturer Flyin' Miata
Flyin' Miata exclusive Yes
Fits Exocet? Yes
Proposition 65 Warning: Cancer and reproductive harm
California emissions No
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