Air and Fuel› Fuel Injection Systems and Components - Electronic

Flow Force

FF640 640cc/725cc Fuel Injector Kit

$329.00

SKU: FF-640-NB

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Special Order
Ships in 4–6 weeks
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$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The FlowForce FF640 is a plug-and-play injector kit for NA/NB Miatas. These injectors flow at 640cc in NA Miatas and 725cc in NB Miatas, providing clean idle quality and headroom for performance builds. The kit uses new OEM EV14 injectors matched to within +/-1% at idle and wide open flow. It is suitable for turbocharged builds targeting approximately 300-350hp.
Show original supplier description
The FlowForce NA/NB 640cc Injector Kit, also known as the FF640, is designed as a flagship, plug-and-play fuel delivery solution for Mazda Miatas. These injectors are carefully matched from new OEM EV14 units, ensuring a flow rate consistency of +/-1% at both idle and wide-open throttle. This precise matching is crucial for maintaining drivability, especially in 4-cylinder engines. The kit delivers 640cc/min in NA Miatas and 725cc/min in NB Miatas, offering sufficient capacity for serious street and track builds. FlowForce estimates these injectors are suitable for turbocharged applications aiming for approximately 300-350 horsepower. Installation is facilitated by designed components that make the injectors plug-and-play for 1990-2005 Mazda Miatas. However, this kit requires standalone engine management. Users are advised to consult the provided installation and configuration guidelines for proper setup. While the stock fuel pump may suffice for some NA/NB builds with FF640 injectors or smaller, a DW200 fuel pump is available as an optional upgrade for enhanced performance and compatibility.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandFlow Force
Part NumberFF-640-NB
CategoryAir and Fuel
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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

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