Do I need different settings if I use 98 octane for my 07 Dyna? I have Vance & Hines Slip ons, SE Air filter & Fuel pack.

 

No, and I don't see any benefit of using the higher than recommended octane if you have stock compression.

BTW, where can you get 98 octane?

 

If you live where the race cycles or go-karts there is always a station nearby that sells racing fuel to them. It is usually pretested and approved for the race. I can get 103 octane locally.

 

Octane is gasolines resistance to burn. The higher the octane, the harder it is to ignite. Thus making it harder for your motor to use. So unless you have changed the timing of your motor or have really high compression use a lower octane gas. In my opinion, HD only says to use 91 octane because its an air cooled motor and they want to avoid pinging caused by a really hot motor with low octane gas. So if you can use 89 with out your motor pinging youll get more mpg and spend less at the pump.

Chris