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


MPH versus RPM Calculator

Tire Size
Section Width: mm
Aspect Ratio: %
Wheel Diameter: in
Use: Calculated Actual
Diameter: * in in
Circumference: * in in
Revolutions/Mile: *  
* calculated from tire size--do not change
Gear Ratios
1st :1
2nd :1
3rd :1
4th :1
5th :1
6th :1
Overall Drive Ratio can be computed at Calculate Gear Ratios page
Speedometer Gear
Speedo Revolutions/Mile:
Drive Gear Teeth:
Driven Gear Teeth:
Calculate: MPH RPM
Lower Bound: RPM MPH
Upper Bound: RPM MPH
Increment: RPM MPH

The reset values displayed are from a 1994 FXDL Harley-Davidson Dyna Low Rider. All late model Harley Big Twin models have similar. The Rear Wheel Sprocket can vary, with belt drive models using a 61, 65 or 70 tooth sprocket. Below is a table of typical values for late model Harley-Davidson motorcycles.

Make Model Engine Sprocket Clutch Sprocket Trans Sprocket Rear Wheel Sprocket Final Drive Ratio 1st Gear 2nd Gear 3rd Gear 4th Gear 5th Gear
HD FXDL Domestic 24 37 32 70 3.37 3.24 2.21 1.60 1.23 1.00
HD FXDL Export 24 37 32 65   3.24 2.21 1.60 1.23 1.00
HD FXDL Australia 24 37 32 61   3.24 2.21 1.60 1.23 1.00
HD EVO 883 Sportster 35 56 27 61   4.30 3.15 2.29 1.88 1.00
HD EVO 1200 Sportster 35 56 29 61   4.30 3.15 2.29 1.88 1.00



1998 John A Bolton.
All Rights Reserved.

Table of Contents
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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 -+-