If you alter the fuel mixture, you need a wideband. You don't have to, but it would be unwise. Dependent on which version of the SSAFC you purchased, you may or may not have a datalogging feature. If you do get the version with datalogging, this will make tuning easier. I had a V1 for about 1 and a half, and it was fine because I was able to manually make adjustments, road test the car, watch the AFRs and correct as necessary. But that got time consuming and I got more mods, so I sold my V1 and bought a V2 (which still doesn't have the datalogging portion setup and it's been over a year) so that I could datalog my road tests and make adjustments based on the recorded data instead of looking at the wideband, then the road, then the wideband, then the road, then the wideband- see how long that could take? You will have to have another O2 bung welded in assuming there isn't one already. IF you get V2, you'll connect one of your input wires to your wideband for datalogging. The SSAFC can't "tune on the fly" because you have to be KOEO (key on, engine off) to write the map to the SSAFC.