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


The V-Twin Motorcycle Performance Guide is your source of information to build, tune and maintain high performance Harley-Davidson street and racing motorcycles. You will find the information needed for tuning, modification, preparation and maintenance for your Harley-Davidson motorcycle engine. Whether you are a new rider looking for  step-by-step instructions to modify a CV carburetor, installing a new cam, want to find out what impact drag pipes have on horse power and torque of your Harley-Davidson engine, or an experienced drag racer looking for the latest cam specifications, the V-Twin Motorcycle Performance Guide has the technical information you can use.

For interests ranging from motorcycle drag racing, hot street performance or just getting the best possible performance from your current bike, V-Twin Motorcycle Performance Guide provides a reference guide and forum for your interests. This is a source of solid technical information that you can put to use today. When it comes to engine tuning, changing carburetors, carburetor re-jetting, picking a camshaft, camshaft installation, dyno tuning, exhaust systems, cylinder head modifications, performance modifications, suspension tuning or just routine maintenance, V-Twin Motorcycle Performance Guide has the answers you need.

Information provided in the V-Twin Motorcycle Performance Guide covers engines made by Harley-Davidson and its clones. We have included information on  the 1340 Evolution engine, Twin Cam 88, Twin Cam 95, Shovelhead 74, Shovelhead 80, Sportster Evolution, Sportster Ironhead, Sportster XR, and Buell. If you can't find the engine you have listed here, its to valuable as a museum piece to modify the engine.


Looking for the easy way to increase the horsepower of your big twin motorcycle? Making Power is your step-by-step guide to improve your horsepower and torque.
We have assembled three different Evolution engine performance packages that can be put together in a weekend.
Build a 64 horsepower Stage 1 bike
Build a 74 horsepower Stage 2 bike
Build a 82 horsepower Stage 3 bike
Build a 95 horsepower Stage 3 bike
Twin Cam engines with fuel injection have become a favorite performance platform over the past couple of years. Nightrider offers you information for a variety of upgrade paths.
128HP TwinCam 95CID engine offers high end performance
100HP Twin Cam 95CID street engine


Confused about your fuel injection system? We explain how your Harley-Davidson motorcycle fuel injection system works with our EFI 101 class.


The Horsepower Gallery provides a quick list of horsepower obtained by many engine combinations. The horsepower, engine type, cylinder heads, carburetor, camshaft and frame type are all listed for reference.
The Drag Strip Gallery showcases some of the quickest V-Twin Racers around. Compare your times to these racers, or better yet send your results to us.
The Land Speed Racing Gallery is the ultimate challenge. Just how fast will a V-Twin engine run. If you thing your bike is fast, see what can really be done.


The Performance Shop Manual is a performance and technical reference manual for engine modifications. This is where you will find all the motorcycle modification information. There is a lot of serious v-twin performance information available for your review. 


The Shop Manual Appendix section contains contains information of interest to all high performance motorcycle riders. Here you will find a Shop Manual that provides information on maintenance, tuning, shop data  and troubleshooting your motorcycle. 


Ever wonder how the best racers always seem to know how their motorcycle is going to perform? Lots of experience is one way, the other is the use of powerful computer tools that predict performance and tuning information. The selection of motorcycle and automotive Performance Calculators provide ways to:

Estimate your engine horsepower
Estimate your top speed and how modifications will change it
Estimate your 1/4 mile time and how modifications will change it
Estimate your 1/8 mile time and how modifications will change it
Determine the best exhaust pipe length
Compute air density
Compute overall gear ratios
Compute cubic inches displacement for an engine


The Links provide a list of manufacturers of high performance motorcycle parts and accessories. Most of the premier providers of Harley-Davidson performance equipment are listed here.


Search allows you to do a keyword search of the V-Twin Performance Guide site. Enter the information you are looking for, and it will find the pages to visit.


The Miscellaneous section to V-Twin Performance provides the V-Twin Café with an outlet for new, serious or whimsical information. You never know what you may find there.


The Books and Manuals section gives you the names of essential items for your high performance reference. You can order these performance books and manuals for your Harley-Davidson thru the Motorcycle Performance Guide by special arrangement from Barnes and Nobles. A wide variety of motorcycle books are available online from Barnes and Noble.


Table of Contents
Search the site 
Nightrider COPYRIGHT

Ask us a Question

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 -+-