ok, ive asked like way too many q's recently cuz i have no luck trudging thru that nasioc ****...so those who keep answering thanks for puttin up with me. i finally got my v2 boost gauge in and all the stuff works. when im driving however, it reads a vacuum of around 20psi and only shows boost once i really get on it (60% throttle and above) is this normal? and what is the idle vacuum/boost supposed to be? im running cobb stage 2 on an 05 saabaru if that helps/makes any difference. thanks again. ill post pictures soon.

 

did you put any creases in the boost line while you installed it? is there anything else in the line that may hinder the control unit from giving you an accurate reading?

 

no creases...i did use a universal t fitting with no pill restrictor and since it was universal i had to cut off the extra parts, however i dont think i trimmed the hole to its full size...think that might be part of it?

 

anyone can tell me what idle reading is? is it normal to read vacuum half way into throttle.

 

If you are coming on Sunday, I can take a look at it.

 

shoots! im gonna be there. soon to give u a call.

 

the negative reading is in Hg(AKA mercury) and what you are seeing is totally normal. This freaked me out too when I first got my WRX cause I didn't fully understand how a turbo charged motor functions.

When you are idle about -20-22Hg is normal, if you get on it with the stock ECU you should see if go to about 14psi in gears 2-5, it may even read a bit lower with the stock ecu.

If you are dead stopped, and rev your engine you should see the needle go to zero.

The ECU will only apply boost when the car is under load. The pressure the turbo produces is controlled by a combination of a boost solenoid , and the wastegate on the turbo(bigger turbos have use external wastegates). if you have the peddle to the floor(WOT) the wastegate will close part way to build boost, and will open up to stop building boost.

For me, seeing this diagram helped clear some things up:




I realize I totally went off on a tangent but I am tired and kind of zoning out.

 

sweet, thanks for the clarification. never had boost in previous cars, and never read a post about what i should be seeing on the boost gauge, but what you say is what i see now on my imperial boost. thank you much!