[Koozie]

With the HD tuner you will gain a little but its not going to be anything big because its an EPA restricted device. In my talks with DynoJet about my 24 RG, they told me that the stock air cleaners are basically simple forms of a high flow air cleaner. I know you want to maintain the warranty but you'd see much better gains with an aftermarket tuner. Fuelmoto published dyno charts of a bone stock 24 RG 117 with an enhanced tune with Power Vision tuner and it made good improvement over stock. They also have one with just a 2-1 exhaust and PV tuner and that made even better numbers without a cam. Both Dynojet and fuelmoto told me these gen 2 M8's can make good power but are limited by the tune and fuelmoto's dyno charts with the power vision tuner proves that. Now to answer your question, no, you dont need an air cleaner but you wont see or feel the gains you want without an air cleaner and a better tuner. Welcome to the forum

On air cleaners I keep the factory air housing and changed to the SE Hi Flow filter from the factory paper filter. But same factory housing as standard. I been questioning if it really is a difference in the filters
I also have the SE Pro tuner and the dealerships left it plugged into my bike harnesse because I added Bassani 2-1 Comp pipes