Do you take it from the Map Sensor line, or the Dump Valve line?

If you take the boost gauage pipe from the map sensor pipe then surely it's gonna tell you what the car SHOULD be running (boost) according to the map sensor. and if you take it from the dump valve one it's going to tell you what the actual PRESSURE is?


Many thanks,



Also what's the best stuff to use for it? (not the blue stuff)
I think I'm going to get Diesel injector pipe