Tach off?
 

The last few days I have been going over my setup looking for anything that might be making me spool 1k later than what I was expecting and was unable to find anything to cause such a delay. After looking at some datalogs today I noticed I start making boost close to where I first expected it,~2700 RPM. The problem turns out to be my tachometer in the car is WAY off. According to my boost gauge and tach I start making boost around 3800 rpm. As far as I can tell my boost gauge is fairly accurate so the problem lies in the tach.

Is there any way to adjust it or is the best way to run an output from MS, instead of getting its signal from my igniter?