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ThunderMax 50 ECM with Auto Tune Closed Loop System

This product fits a variety of motorcycles. Please select yours so we can find the right part and guarantee fitment. Select A Motorcycle

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J&P Part: 402-613

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How Auto Tune Works

ThunderMax 50 ECM with Auto Tune Closed Loop System

• 88″ EFI engines only

• Have full control of your EFI system, freedom to make major and minor adjustments without a master’s degree in electronics and computers

• CARB-approved, street legal in all 50 States, including California, Closed Loop System - ARB Executive order # D-644

• ThunderMax is a completely new product that replaces the factory module, not an add-on box or signal modifier

• Purpose-built to deliver uncompromising performance but you don‘t have to be a rocket scientist to install it, program it or make adjustments

• As simple as we’ve made it to install and use, don‘t be fooled into thinking that this not one of the most sophisticated systems you can buy for your Harley

• Using the supplied SmartLink software and communication cable, you can adjust or monitor virtually every parameter of the system

• The ThunderMax makes sense in the long run as the system can grow and change as your engine does - just load a new map

• ThunderMax software, firmware and maps updates are free and accessible 24/7 with an Internet connection so you‘re only a mouse-click away from the latest available data and product support

• Backed by a 3-year manufacturer's warranty

Important Product Notes

Product Specs

Manufacturer Part Number: 309-370

Open or Closed Loop: Closed

Sold in Units: Each


This product fits a variety of motorcycles. Please select yours so we can find the right part and guarantee fitment. Select A Motorcycle

Click (+) to view all compatible models

Harley-Davidson® Models

Dyna Low Rider EFI FXDLI : 2004–2005
Dyna Super Glide Custom EFI FXDCI : 2005
Dyna Super Glide EFI FXDI : 2004–2005
Dyna Super Glide Sport EFI FXDXI : 2004–2005
Dyna Wide Glide EFI FXDWGI : 2005
Softail Deluxe EFI FLSTNI : 2005
Softail Deuce CVO FXSTDSE2 : 2004
Softail Deuce EFI FXSTDI : 2001–2005
Softail Fat Boy CVO FLSTFSE : 2005
Softail Fat Boy EFI FLSTFI : 2001–2005
Softail Heritage Classic EFI FLSTCI : 2001–2005
Softail Heritage Springer Classic EFI FLSTSCI : 2005
Softail Heritage Springer EFI FLSTSI : 2001–2003
Softail Night Train EFI FXSTBI : 2001–2005
Softail Springer EFI FXSTSI : 2001–2005
Softail Standard EFI FXSTI : 2001–2005
Touring Electra Glide Classic EFI FLHTCI : 2002–2005
Touring Electra Glide Police EFI FLHTPI : 2005
Touring Electra Glide Standard EFI FLHTI : 2003–2005
Touring Electra Glide Ultra Classic EFI FLHTCUI : 2002–2005
Touring Electra Glide Ultra Classic FLHTCU : 2005
Touring Road Glide EFI FLTRI : 2002–2005
Touring Road King Classic EFI FLHRCI : 2002–2005
Touring Road King Custom EFI FLHRSI : 2004–2005
Touring Road King EFI FLHRI : 2002–2005
Touring Road King Police CA EFI FLHPEI : 2005
Touring Road King Police EFI FLHPI : 2005

Customer Reviews

Overall Rating:
5/5 based on 15 ratings

5 by

Unbelievable tuning all in less that 10 minutes. Was only able to load stock base map, when I had BUB 7 2 into 1, Arlen Ness Big Sucker Stage I filter. T-Maxx rocks and adjusted from Base map to may set up with no issues.

5 by

easy install

5 by

Best bang for the buck. I have tuned my bike for its best performance and can fine tune it any way and any time I want to. Newest software update allows me to use multiple tuning maps without having to use the laptop. If I am traveling heavy with 2 up and luggage I can call up the map just for this riding environment on the fly and the bike runs great. When riding solo and doing high performance riding I call up the tuning map for this riding style and the bike performs great again all without the laptop. Great product and WELL Worth the money.

5 by

Works great easy install

5 by

I have never had anything but stock electronic control units on my touring bikes. Friends recommended ThunderMax enthusiastically so I went to JP Cycles and bundled a large purchase with pipes, air cleaner, etc. Unit works perfectly. Better throttle response, more hp and torque, cooler engine temp. Wish I had upgraded sooner.

5 by

In the last few weeks I spent way to much money on my '09 RoadKing. Here is how it played out. I ordered a set of Cobra Speedster Duals with PowerPort, Arlen Ness Plain Finish Stage I Big Sucker Kit, Vance & Hines FuelPak. Parts came in and did the install. Called Vance and Hines to verify which map to use. Had decel popping, occasional backfiring, poor throttle response, and lst a major portion of my top end. Put a little over 250 miles on it to see if it would level out. I ordered a Throttlepak to try and eliminate the newly acquired poor throttle response. Which I never installed, The next day I ordered new tires, a Thundermax, from J&P, and ordered a Road Zeppelin Seat from Harley. The seat and ThunderMax came in on Wednesday and the tires on Thursday. I went and had the tires mounted and balanced. When I got home and let the bike cool down I installed the Thundermax and seat. I finished up about 8 last night and decided it was time to go see how all was working. The tires were a mist at the time. The seat made my wife's and my butts very happy. The ting that blew my mind was how the bike was running. It has never run that smooth. at 60 it sounded like a nice smooth idle almost like it wasn't even working. I found a couple of good grades to run up and there was all my top end back just smoother. All I can say is that I am sold. In the future one of these will be going on my '13 Wide Glide also. Good Bye stock Delfi. Hello Thundermax. I guess I have a bunch of stuff fixing to hit ebay to try and recoup some of the funds spent.

5 by

If you are going to use this on a 2012 or later harley touring, get the 2011 header pipes to O2 sensor bungs on the 2011 work the 2012 do not pipes are the same otherwise.

5 by

best improvement for the money you can do

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Important Product Notes

This item cannot be returned once the package is opened. Manufacturing defects must be addressed through the manufacturer directly. EPA Note: Requires exhaust system equipped for or modified for use with oxygen sensors Legal in California only for racing vehicles which may never be used upon a highway.

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