REF: Engine Conversions & Upgrades
Typical Staged Sportster Engine Upgrades 1)
Paying Taxes
Stage 0: Stock = HP- 40 for 883, HP- 50 for 1200 (average)
Stage 0.5 (also known as “The Harley Tax”)= HP- 50 for 883, HP- 60 for factory 1200 (Example)2)
Stage 1 Upgrades
Quote: Stage 1 and Harley Tax are synonims and include Pipes, Air Filter and Carburetor re-jetting/ ECU re-mapping 3)
Stage 1.0 = HP- 60 for 883/1200, HP- 65-70 for factory 1200 (Example)
4)
High Flow Air Cleaner AND
High Flow Exhaust AND
Fuel/Air ratio adjustment : Jetting for carburetor, modify fuel tables in ecm with EFI bikes.
Known Stage 1 883 configurations
This is just examples of what has worked on some bikes. Each motor may be different in it's own unique way.
883 Engines:
Known Stage 1 1200 configurations
Stage 1.5 Upgrades
Stage 1.5= HP-65 for 883/1200, HP- 70 for factory 1200 (Example)5)
Stage 2 Upgrades
Quote: Stage II: Stage I plus cam upgrades 6)
Quote: Stage II: Camshaft, Larger displacement, Higher compression 7)
Stage 2: Stage 1.5 plus: (Example)
8)
Andrews N4, N8, or SE bolt-in cams instead of N2
SE S1 Lightning or other bolt-on +/- 10:1 heads
HP=75
Options:
2 into 1 header system, add +/- 7 hp
SE carb (or equivalent), add +/- 3 hp
XR750 (or other) valve springs, no gain
Stage 2.5: Stage 2 plus
Professionally ported 10:1 or higher heads
Matching (to head) domed pistons
XR750 valve springs or SE cam kit
2 into 1 header system
SE,S&S Super E, or Mikuni HSR42 carb
HP=90+
Options:
Stage 3 Upgrades
Quote:Stage III: Its on like Donkey Kong ! 9)
Quote: Stage III: Boring and/or Headwork and/or Forced Induction and/or Nitrous 10)
Stage 3 = HP- ????
Stage 2.5 plus:(Example)
11)
Displacement: pi x (radius squared) x height (example: 4 inch bore, 4 inch stroke) = 3.14159 x (2 squared) x 4 = 50.265ci of displacement per cylinder
Cubic Centimeters to Cubic Inches: cc ÷ (2.54 cubed) (example: 1200cc) = 1200 ÷ (2.54 cubed) = 73.23ci
Cubic Inches to Cubic Centimeters: ci x (2.54 cubed) (example: 100ci) = 100 x (2.54 cubed) = 1638.7cc
Horsepower: (torque x rpm) ÷ 5252 (example: 80 ft-lbs at 4000 rpm) = (80 x 4000) ÷ 5252 = 60.93hp
Torque: (horsepower x 5252) / rpm (example: 100hp at 4000 rpm) = (100 x 5252) ÷ 4000 = 80 x 4000) / 5252 = 131 ft-lbs.