I am in the process of trying to tune my car and I have noticed on a good pull, say from 4,000 to 7,800 rpm at about 13psi the rpm on the graph surges all the way up it like a saw blade...same thing with the bost at wot in the same rpm band the bost will do the same thing from 9psi up to 15psi. has anyone had the same experence when data logging?

 

Not sure what you are seeing, may help to post a datalog for folks to look at. What you describe does not sound right unless your clutch is slipping or your wiring is messed up and sending erroneous signals to the PFC.

Can we assume you're running a PFC? your sig says stock ECU.

 

Are you talking about the graph within the Commander or the DATALOGIT graph?

 

it is a pms unit.....I know out datted