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K&N 77 Series Metal Intake Kit - 77-2578KS

  • $337.99
  • Free Shipping
  • Ships Between 3/27 - 3/29
  • What Do You Drive?


  • Color:
  • Part #:
  • Estimated Horsepower Gain: 9.19 HP @ 4914 RPM
  • Download installation instructions (PDF)
  • Includes K&N filter # RF-1048
  • Compatible with filter wrap # RF-1048DK (not included)

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K&N 77 Series Metal Intake Kit Part #77-2578KS Customer Reviews

Average Rating

6 Customer Reviews

2011 Ford Flex 3.5

Reviewed by Renfred Z (ORANGE PARK, FL) Reviewed for a 2011 Ford Flex — Sep 02, 2017 4:49 PM

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Very happy with cold air intake, YouTube video was much better at explaining instillation then the paper instructions

Quick install

Reviewed by Brian Z (CHESAPEAKE, VA) Reviewed for a 2012 Ford Flex — Aug 02, 2014 9:38 AM

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The installation was easy, sound is amazing and a noticeable increase in acceleration. I just wish that the shroud covered the whole filter like the ARID system. Don't think there is any benefit to fuel consumption but that maybe because I have a heavy foot sometimes.

2010 Ford Flex (3.5 liter, not ecoboost).

Reviewed by Clint S (Vancouver, WA) Reviewed for a 2010 Ford Flex — Jul 25, 2014 8:46 PM

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Impressed with the instructions and how custom this really is. Went on easy enough only had to backtrack a couple of times. Makes the 3.5 liter v-6 sound pretty tough (non-turbo), we'll see how it does on MPG and towing (if a few horsepower is even noticeable). Biggest concern is when it comes time to clean it and remove the filter, a lot of stuff will have to be loosened, disconnected and moved to to the tight clearance. Great value, fast shipping. Came with the bonus cleaner and oil.

09 Flex

Reviewed by Alvin H (Lima, OH) Reviewed for a 2009 Ford Flex — May 23, 2012 2:57 AM

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1 of 1 people found the following review helpful.

Easy installation, small improvement in power and no improvment in gas mileage

K&N review-easy, except for missing hardware

Reviewed by JOHN B (Strawn, TX) Reviewed for a 2012 Ford F-150 — Mar 20, 2012 7:21 AM

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Installed per included instructions. Everything fine till time for attachment of Air flow sensor and plastic adapter. 2 screws/bolts were missing from hardware kit: 4mm x.70 and defective plastic elbw for hose attachment. Threads would not filt metal adapter. One was course thread other was finer thread. Found an adapter at a salvage yard.

Awesome product

Reviewed by Sean M (Niceville, FL) — May 28, 2011 11:01 AM

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1 of 1 people found the following review helpful.

Put this on my 2009 Ford Flex and had instant horsepower and performance. Took about 1/2 hr to install and have loved it ever since. Vehicle sounds throaty now...too cool.