Get XiED(tm)! Performance Parts

Don't let the Harley heat monster ruin your riding.
Reduce  Engine Surging
Improve Throttle Response
Reduce Engine Ping


HD 2007/2008 Engines

High Heat on 2007/08 HD engines

HD 2007/08 Performance Recommendations

Cool your exhaust temperature with the Wide Band O2 upgrade for 2007/08 HD

Harley Camshaft Specification Tables

HD Twin Cam Engine Builds
TC 128 HP 95 CID
TC 100HP Street Engine

The basics of Fuel Injection explained

Rammer Performance Air Cleaners
TC Performance Heads 100+HP

Pro Tuning on a Shade Tree Budget


Ignition Modules

Performance and Technical information on ignition modules

Single fire vs. Dual fire Ignition Systems

There is a school of thought that states a single fire ignition system produces a smoother running engine than dual fire ignition. Arguments for single fire ignition center around firing the second plug when the cylinder is not on the compression cycle, the 'wasted spark' theory, the 'wear out the plugs' theory, and the 'not enough spark in the right cylinder' theory. Bike Tech is not aware of any hard evidence to support the "smoother running" statements since this is a highly subjective rating. Since many people want to get a smoother running engine, they will perceive that their motor now runs smoother when a single fire ignition system is installed. While it is possible that a specific engine combination does get smoother, it is likely that more than an ignition module setting was changed. Normally the ignition module, coil, spark plugs and plug wires are changed at one time. Any engine that has a few hundred miles on these parts may smooth out when they are changed.

No difference in horse power has been seen between a single and a dual fire engines in testing of 1994 stock 80 CID motors by Bike Tech using the same ignition and coil to test both modes. Bike Tech tested a DYNA 2000 ignition system with a Crane Single Fire coil in both single and dual fire modes. A single fire coil can be converted to dual fire by simply placing a jumper between the two coil positive leads. Testing under conditions where the only difference was the single fire or dual fire mode produced no difference in horse power. Both horse power curves were identical.

Ignition Modules Tested

Ignition System Component Diagram
Single vs. Dual fine
Solving Sportster Detonation Problems
Dyna 2000 Ignition Settings
Screamin Eagle Street Module
Crane HI-4
Dyna 2000
Stutter Box


Table of Contents
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Nightrider COPYRIGHT

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Modification, Installation, Maintenance and Tuning Index  will help you find most of the information you want on one page.

How to get Professional Tuning Results at home
Testing the Innovate Motorsport LM-1 portable air fuel meter

Profession Tuning on a Shade Tree Budget

Veypor VR2 Data Logger and Instrument Panel
Video Installation and Demo
Purchase VR2

Engine Performance
How to Build a
TC96 2007 Engines
TC88 70HP Stage1  
TC95 128HP Stage 3
TC95 100HP Street
TC96 2007 Stage 1/2
EVO 64 HP Stage 1
EVO 74 HP Stage 2
EVO 82 HP Stage 3
EVO 95 HP Stage 3
883 to 1200 Upgrade
Shovelhead Modifications

New EFI for EVO and TC

Performance Gallery
Horsepower Gallery
Evolution 80
Twin Cam 88/95
Evolution Unlimited
Sportster Unlimited
Drag Strip Gallery
Land Speed Racing Gallery
CV Carburetor
Modifying the CV carb
Tuning a CV carb
Selecting a cam
Install a TC 88/95 cam
Install a Big Twin cam
Install Sportster cams

Camshaft Specifications
Twin Cam

Exhaust Systems
EVO Exhaust Testing
TC Exhaust Testing
Khrome Werks AR100 test
Making Drag Pipes Work

Shop Manual
Carburetor Troubleshooting
Finding Manifold Leaks
Cylinder Heads
Pistons and Cylinders
Belt Drive
Shop Manual Appendix
$20 Bike Lift
Plug Wires
Spark Plugs
Engine Tuning
Nitrous Oxide
Motor Oil
Stutter Box
General Information
WEB Links
Buy Books and Manuals
Performance Calculations
Estimate Horsepower
Estimate 1/4 Mile Time
Estimate Top Speed

Engine Displacement
Exhaust Length
Gear Ratios
Air Density

The Nightrider Diaries
The ramblings of a genius a, a madman and something in between.

Where is Sifton Cams?

Autocom Active-7 tested

Harley-Davidson EFI
-EFI basics explained
-EFI modifications explained

183 HP, 2 carbs, 2680cc

Copyright 1997-2006  Stephen Mullen, Oldsmar, FL -+-