So I definitely don't like the looked of the stock air cleaner and would like to go with something else. But it says a recalibration is required for proper installation and will allow engine to rev to 7000 rpm.
So form the factory it can't rev to 7000 rpm? If I did go to another air cleaner and did a EFI controller would it do the same thing?
Thanks and sorry if this is a repeat question
(my bike is a 2008 nightster)

 

You only have to change your fuel map if you change both your exhaust and your AC. If you only change one you will be fine with the stock map. If you change both your engine will run lean. Fuel management systems for EFI is a topic that has been beaten to death and you will receive a hundred different opinions on here ranging from the cheapest option of Xieds up to autotuners that will run you $800

In regards to allowing your engine to rev to 7000 rpm. No, your bike does not rev to 7000 stock, I forget what the stock redline is but I believe it is about 6000 rpm. When you get a Harley Davidson stage 1 map installed it changes your rev limit to 7000 rpm. You can invest in a SEPST and this will give you the stage one map and also include the smart tune feature so you can tune your bike to any other changes you make in the future. Larger engine displacement, cams, any other mods.

 

OK cool thanks, that helps a lot, I am getting both AC and exhaust but that's it