mossy26

hi all
just bought my impreza wrx,its my first car with a turbo so just been getting used to all its bits etc,but the 1 thing that caught my eye was the boost gauge reading never changing when driving,so had a look around and found that the pipe wasnt connected because it was too short,so got a longer pipe and fitted it,however now the readings im not sure are right? the vac is readin 20-22? is this bout right,gauge goes up to 1 in pressure side when puttin foot down?

thanks all.

joz8968

iTrader: (13)

What's the MY of WRX? This will tell us whether c.1bar is correct target boost for your MY.

Yeah, there is a set of SI units (can't remember what) where the reading of "- (minus! obviously) 20" is correct for full vacuum i.e. idling on a shut throttle.

mossy26

mine is '94 jap import

also eerrr "si units"? lol

joz8968

iTrader: (13)

What are the -ve vac units, and what are the +ve boost units, as marked on the gauge?

FTR, the 94 WRX saloon (I assume a saloon?) has a +ve boost target of : 0.79 bar... or 0.8 kg/cm^2... or 11.5 psi.

mossy26

vac(inhg)
pressure(psi)

joz8968

iTrader: (13)

Okay.

In that case then vac should = circa -180 to -200 inHg.
If gauge reads to 2 digits only, then it must also have "x 10" marked on it somewhere(?)

As above, target boost = circa +11.5 psi

mossy26

well what ur sayin does make sense with readings etc,but i cant see a x10 on the gauge but my psi part is in 2 digit blocks 2,4,6,8,10 etc

joz8968

iTrader: (13)

Yeah, the vac reading does corroborate with the units - so all good.

Not worried about the psi part.

Does the vac reading read "-20" (your quote).... or "-200"? It should be -200 if the unit is inHg.
If it's -20 i.e. only marked to 2 digits for ...-10,-20,-30,-40... etc. (and not 3 for ...-100,-200,-300,-400...etc.), then the gauge really should have "x10" written on it. Comprende?

mossy26

vac does read 0-10-20-30
no x10 tho
but i understand what ur sayin tho

joz8968

iTrader: (13)

Yeah cool. So long as it not reading, for example, -5, -7, -10 etc.

The fact that it is -20, is supposed to represent the correct circa -200 inHg value

joz8968

iTrader: (13)

What a **** I am... -20 IS correct. I was basing it on circa -7 bar (the equivalent bar reading)... But of course that'd be -0.7 bar", not bloody -7!

I'm really sorry about that - what a mistake!