I would put it simpler. Stage 1 is the things you can do outside the motor, although you have covered those. Stage 2 is minor internal work, such as cams and I would include a bolt-in big-bore kit. Stage 3 is starting to cut metal, such as porting heads, going to bigger bores that require cutting the crankcase mouths, etc. All require some recalibrating of the electronics.

 

Most of what I read says Stage One is improved air flow in and out. Air intake and mufflers. But I beleive an EFI mod is required as part of a Stage One either Dyno tuning or a Power Commander. The engine is very lean at the factory setting and even leaner with the improved air flow with the stage one air cleaner and higher flow muffler with out the change to the EFI

The EFI mod applies to every stage 1,2,3,&4 because it changes with ever level.

One reason the Stage One is so popular is everyone wants there Harley to sound like a Harley. but, in my case I want my Harley to run like it should before the EPA got ahold of it. Due to the excessively lean factory setting the engine is hot! Letting it breath and adjusting the fuel to where it should be cools the motor down some. Living in Texas this is almost a must.

Stage II, Is just letting the motor breath even more!!!! Cams and an EFI change to match. this may also include a push rod change and improvement to how the cams are driven.

Stange III. time for real money. There is no substitution for Cubic Inches. Big bore kit, head work, clutch to handle more power and of course another efi change.

I'm very happy with my stage 1 and once everything else on the bike is the way I want it I may look at a cam,pushrod, drive and lifter change.

 

Not that you have to buy this stuff but this is a good description of all that is involved at each Stage:

 

 

Stage 1 money sounds like a Harley should
Stage 2 more money now it runs like it should
Stage 3 More money finally the way I want it
Stage 4 Even more money it will be just right when I get the NO2 and turbo installed next.

 

Thank goodness thats been cleared up after 7 years...
☺

 

LMFAO
Right!!

 

Can you repeat that again, please? lol.