Ya you can get a laptop and jack with the tune all you want but with out that dyno it is just a shot in the dark. Change some thing and it needs tuned again.
Exactly, that's why guys including myself will have multiple tunes after they step off the dyno. You save those tunes and can easily just pop a new tune in. You can always fine tune it at the track or street by referencing your data log that keeps track of AIr fuel ratio, fuel pressure and a host of other things that you choose to log, rpm etc to watch for converter slippage or whatever.
For example.
1 tune for 15 lbs of boost with meth injection to kick in at say 8psi on pump fuel.
Another for more timing, timed NOS for the launch and boost limited to 6lbs at launch NOS to shut off when boost hits 10 psi max boost is 22psi on say e85. Etc etc
