For anyone who has not seen data logging, here is a quick video playing back one of my data log runs using HPTuners VCM Scanner. It logs and displays anything the ECU knows about - that's the new AFR value at the top left. Tuners like Ryan use these data to decide which changes to make to the tune.
You simply haul your laptop into the rig, plug the HPTuners connector into the ODBII port, fire up the software, hit record and drive. It's pretty cool.
Have I mentioned that Ryan really knows his stuff? I'm amazed at what he has done already. I can't recommend him strongly enough for anyone who needs some tuning. I've heard especially good things from folks here - including our fearless leader,
@Chris.
Now that I've sent him a data log with the AFR info, he is starting to tune for performance. I'm stoked.