DK Custom Products

Phone: 662.252.8828
Text: 662.420.4891

606 Performance Stage I Upgrade Kit For Harley Softail Twin Cam

Availability: In stock
Item #: DK-SFT-TC-STG-606
Manufacturer: DK Custom Products Pkg

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DK Custom Basic Stage I Kit for Twin Cams Harley-Davidson Dyna Softail Touring K&N air cleaner XiED Power Vision TTI Thunder Torque Insert Slip ons Full Exhaust






  • Outlaw HiFlow 606 Air Cleaner System w/ EBS
  • Your Choice of Exhaust
  • Your Choice of Tuner
  • E-Z Installation


Package Discount ~ Save $25 - $200


We've made picking Your Stage I Upgrade Easy. 

-All you do is choose your desired options in the drop-down menu above. 

-You will have Your Own Customized Stage I Kit, reflecting automatic package discounted pricing*.


This Upgrade Package is based on the Outlaw 606 HiFlow Performance Air Cleaner System. 

If you would like to build your Stage I Upgrade with a different Air Cleaner System, Click HERE. 

You can read about the differences between our Air Cleaner Systems, by Clicking HERE

* The discount will show once you add your order to the shopping cart.  After it is in your cart, you can still "edit" it to make any changes you'd like.

Caution:  Motorcycles modified with DK Custom Products High-Performance parts may not be legal for public highway use in some areas.  The user shall determine suitability of this product for his or her use.


Stage I Kits are NOT Created Equal

DK Stage I Upgrades are designed to Give the Most Performance Increase per dollar spent. 

The Best Choices in Peformance, Looks, Sound & Value. 



Overview of a Stage I

(Technical Info: The Foundation of Making More Power)


Stage 1 Kits are comprised of 3 components: 

  1. Free Flowing Air Cleaner
  2. Free Flowing Exhaust
  3. Fuel Management for EFI and Re-Jetting for Carb


 With each of these 3 components there are sometimes a confusing number of choices.


1.  With Air Cleaners there are two basic choices, and an endless number of "Looks" to choose from.

The difference between most air cleaners and the DK Custom Outlaw A/C Systems is the Quality of the Air.

Choice #1 - Unfortunately the EPA mandates have Harley-Davidson and almost every aftermarket air cleaner company pushing the blow-by into the air cleaner.  What comes out of the breathers is primarily exhaust gases and oil, it is also hot.   This is counter-productive to performance & engine longevity.  Harley engines perform better with cool dry air & gasoline, not hot, oily air and gas.  Additionally, the exhaust gas has a lower oxygen content, displacing oxygen on each combustion stroke.

This type of air cleaner is a poor performance choice.


Performance Choice #2 - The Best Performance Choice is an Air Cleaner System that allows only clean dry air into the intake.  

DK Custom Products Line of Outlaw Air Cleaner Systems utilize External Breather Systems (EBS),  allowing only Dry, Clean Oxygen Rich Air into your intake.  

The DK Outlaw Line of Air Cleaner Systems has Many Looks to choose from.

See HERE for details, photos, dyno charts about how important an EBS type Air Cleaner System is to Performance, and Engine Longevity.

You can see details & hundreds of variations  of the Outlaw Performance Air Cleaners HERE.


2.  With Exhaust, there are 3 main factors that are considered:





You can see a LARGE Selection of Top Quality Slip-ons and Full Exhaust Systems HERE.

Whether you are keeping your current exhaust, adding Slip-ons or a Full Exhaust System, they all will be enhanced with the addition of some TTI's.

The "W" Series Thunder Torque Inserts™ (TTI's) will slightly deepen the tone, and, more importantly, will increase the low and mid range power by 5%-20%, by reducing engine pumping loss, & increasing exhaust gas velocity. 

The Patented  TTI's are literally the most power increase per $ spent

of any mod that can be done to a Harley-Davidson motor!


Example of Some Different Exhausts with Thunder Torque Inserts™ Installed



The "Best" Exhaust is what YOU like the Looks and Sound of

The TTI's will Optimize Performance

If you want to use your current exhaust, choose accordingly above.

See HERE for info (and a popular myth) on HOW Exhaust exits the engine, and why "the how"  can make a big difference in Performance.


3.  In the Fuel Management arena for EFI Harley's, there are dozens of choices.  Ranging from doing nothing to spending as much as $600, or more, for a tuner and dyno tuning.  

While it is possible for the modern Harley to run a free flowing air cleaner and free flowing exhaust without doing anything in the tuning/fuel managment arena, our experience has shown that it will run hotter than is good in the long term, AND, will not run nearly as well as it could.  

While the ECM will adjust for changes to a certain degree, they will never adjust past the "too lean" factory (EPA mandated) settings without the help of a Fuel Management Device.


Our experience with thousands of bikes has shown that the best economical choice is one of the XiED Products.  These are Plug-n-Play fuel enrichment devices that will give most Sportsters 80% - 90% of the benefit of a Full Blown Tune for about 20% the cost.  

We have Thousands of Customers that are very happy with their cooler running, stronger accelerating Harley's as a result of using an XiED device.



The FP3 is an almost full featured Flash Tuner, giving you some of the control you get with the Power Vision. However, it does give a lot of control, and it is very easy to use. It connects to your smartphone via bluetooth for programming changes, updates and to display data from your bike (RPM, Gear, temp, etc.).

Because of the smartphone interface it is very popular. While it cannot be used with dyno tuning, it does come with an auto-tune feature..



The Power Vision Flash Tuner can be used to achieve the best possible tune for performance, reliability and economy....  

...All without having to spend any money on Dyno tuning.  With the Power Vision you can choose to Dyno tune if you wish, but, since the Power Vision comes with a Customized Tune from us, plus an Auto-Tune Feature, the vast majority do not find it necessary.  

The Power Vision has the added benefit of several other features-

  • Touch Screen Control - No computer needed
  • Doubles as a Gauge Cluster, displaying your choice of info, up to 6 different read-outs in one screen
  • And many other features (and extras from us) that you can see HERE


 See this LINK for a more detailed overview of all types of tuning options.



 * * *

Want even More Performance after your Stage I Upgrade?  This LINK takes you to a Report of Sleeper Performance Mods...Long Ignored & Little Known Modifications that will Increase Your Power AND Increase Engine Longevity.


Questions? Call us at 662-252-8828, Text us at 662-420-4891 or email us at

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