i want to fit a boost gauge to my rev2 turbo. where exactly on the turbo do i connect it to? also does a turbo gauge have to go from - to + or can it start from 0. i ask this because i can get a gauge for free that goes from 0 to 2 bar, will this be ok?
on the inlet manifold you will find a number of pipes. the will go to various places such as the map sensor, actuator etc.
you can get a tee piece and insert it between one of these pipes and then use the spare outlet to connect to the boost gauge via the pipe supplied.
you may find that the pipe supplied is vastly smaller than the OE vacuum pipe. simply cut a small length of the correct OE vacuum pipe and insert the pipe that will then connect to the boost gauge. get a decent amount of clamping pressure via the aid of acouple of zip/cable ties. they will need to be clamped very tightly over the area where the small pipe goes into the vacuum pipe. insert about 50mm of small pipe intot he vac pipe to ensure a good seal.
i did this on my impreza, so i am not entirely sure which pipe is best to use on the Mr2, but i used the pipe that goes to the map sensor as my feed.
regards the free gauge you have been offered. its personal preference, i have one that reads both vac and boost, and it is nice to be able to see when the turbo is approaching + during spool up.
ultimately you are concerned with ensuring the car is boosting correctly for safety reasons and to identify if the car is over or under boosting due to a leaking pipe etc.
hope this helps.