2021-Newer M8 Touring D&D 650Z-31T Black Billet Cat Complete Stage 1 Power Pack




Fitment: 2021-Newer FLH/FLT M8 Touring Models

This Power Pack Includes:

    • D&D 650Z-31T 2-Into-1 Billet Cat Exhaust System Black  
    • A Pre-Mapped ThunderMax Auto Tune 309-591
    • Arlen Ness Stage 1 Intake or upgrade to a top performing Intake 
    • Optional NGK Iridium Spark Plugs

A detailed description of this package can be found below.  Make your selections from the drop down menus below.

Looking for a different air intake or exhaust?  Call us!  We can build a custom package just for you.



Fitment:  2021-Newer FLH/FLT M8 Touring Motorcycles Will not fit the 2023 CVO Road Glide and Street Glide 121’s with VVT

This complete power pack comes with a 650Z-31T Black D&D Billet Cat 2-Into-1 Exhaust system and your choice/style of the following items:

  • A Pre-Mapped ThunderMax Autotune 309-591
  • Arlen Ness Stage 1 Air Intake (uses stock cover) or upgrade to other options
  • Optional NGK Spark Plugs

D&D 2-into-1 Black Billet Cat Exhaust

  • The M8 Billet Cat 2 into 1 full system is equipped with heat-shields, exhaust gaskets, bolt kit and baffle.
  • This system is designed to increase low-end torque and horsepower.
  • The 2 1/2″ core Vortex wrapped baffle works great on 107″ to 117″ motors. Muffler housing is 4″.
  • 2017-Newer Harley Davidson Touring D&D 2:1 M8 Billet Cat is a stepped header system at 1 3/4″-1 7/8″-2 1/8″ at collector -2 1/2″ where the muffler goes to the header.
  • M8 Billet Cat comes with both 18mm and 12mm O2 bungs so you can use a ThunderMax Auto Tune.
  • Add a matching ghost pipe for that True Dual look and select your tip style from the drop down menus above.

ThunderMax Auto Tune Module features and benefits:

  • Dramatically improved throttle response by allowing throttle blade to open fully below 3500 RPM
  • Eliminates popping, spitting and backfiring
  • Easier starting
  • Increased Engine Performance & Motorcycle Rideability
  • Cooler, Smoother Running Engine
  • Adjustable Idle Speed & Rev Limit Control
  • Automatically Tunes for Riding Style & Riding Conditions
  • Easily Accommodates Bike Changes (Pipes, Cams, and More)
  • 100% Engineered & Made in the USA
  • 3-Year Factory Limited Warranty


Arlen Ness Big Sucker Stage 1 Air Intake for Milwaukee-Eight

  • Designed for use with your factory air cleaner cover
  • This high performance filter is made from red surgical grade pre-oiled cotton for the best in airflow and filtration.  Each filter is washable and re-usable.  Filter recharge kits can be purchased separately
  • In addition to a patented hidden breather backing plate technology we have added an all new filter plate that is integrated for mounting studs and directional air venturi to force more air into the engine
  • Ness air filter’s surface area is over 200% larger that the factory filter for a massive increase in air flow to the engine.


Arlen Ness Inverted Air Intake Series:

  • Black stainless steel jacketed filter is handmade in the USA, and features an inverted pleated top with pleated sides to maximize airflow
  • Forged billet aluminum backing plate features proven radius air inlet, hidden breather hardware, and our industry leading Big Sucker patented technology
  • Forged billet aluminum air filter housings feature built in velocity stacks
  • Available in 4 styles: Slot Track, Deep Cut, 10-Gauge and Beveled
  • All mounting hardware, gaskets, and necessary components are included
  • Maximizes airflow by pulling in air from the face of the air cleaner, as well as the traditional method of pulling air from the sides
  • Synthetic filter with no oiling required that repels water so no rain sock is required

Arlen Ness Monster Sucker 90 Degree Air Intake:

  • Monster Sucker kit features a patented Big Sucker “hidden breather” technology and more filter surface area for maximum performance
  • Hidden breathers are o-ringed at the heads and exit out the mouth of the injector/carb to provide efficient engine breathing, eliminating the need for any external hoses or hardware
  • Filter features a built-in inverted top to pull in air not only from all sides of the filter but also from the front, which results more performance-gaining airflow
  • Each filter is constructed from synthetic material that is water resistant, which in most cases eliminates the need for a rain sock
  • NOTE:  Can be installed on a motorcycle with lower fairings.  Lower fairing will need to be loosened so that the intake can be installed and then re-tighten the lower fairing.

T-Man Performance No Loss Air Intake:

T-Man No Loss Air Intakes are available for both Twin Cam and Milwaukee-Eight™. They feature a K&N 2.375 wide Air Filter for maximum air flow. These air cleaners will work on a stock M8 throttle body and will accept up to a 66mm throttle body with only the change of a velocity stack insert. These inserts can be ordered by calling us.

 Looking for a different style of air intake?  Other air intakes are available for purchase.  Call us and we can create a custom package for you.

Add NGK Iridium plugs to your power pack:

  • Gain up to 3HP just by using these plugs!  Dyno proven!
  • The ultimate in spark plug technology and performance from the industry leader
  • The iridium electrode is 25% smaller than a platinum electrode, and it’s just 1/4 the size of a conventional nickel electrode
  • Ultra-small diameter center electrode reduces voltage requirement and extends ignition system life
  • New metal shell plating has enhanced anti-corrosion qualities
  • Come pre-gapped for quick install
  • Sold as 4 plugs
  • Big gain at a small cost

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