I would do a base run with a G meter on a smooth highway in current configuration before you let him change the timing and a/f maps. You really need to start investing in a logger or else do some 1/4 mile testing at a strip with your guru. otherwise you'll never know if he's improving the cars performance.

I have seen people remap a cars A/F tables for max power, not chemically correct... and the vehicle lost power by pulling less g's in a straight line track. Time to invest in equipment.