i knew there are many threads out there that talks about vaccuum reading on boost gauge and i have over 50 of them. But still cant seem to find my answer. I installed by boost guage 100% correct and sure of and pretty sure there is no leak. However at idle it read 600mmhg and it would slowing go back up to 500mmgh at vacuum. the kg/cm seems to read fine because I never past 1 (stock car). when the car is off it reads a little below 0. So i was wondering if there mite be a possible leak (i dont think there is one because i checked several times) or would it be a defective gauge?

thanks

 

try to use silicone hose
or try the feel is there have any suckion at the end of the hose ( end of the hose to boost gauge with runing engine) subaru spec. at ac off and warmed engine should be around -17hg

 

o by the way what knid of gauge are u using??
i had vdo gauge it reads -19 to -20 hg n and i switched to autometer it reads -15hg cold engine and -16 to -17 hg warmed egine.

 

cool

 

i have a greddy boost gauge. silicone hose eh, i'll see if i can get some its 3/16 hose btw

 

Did you use the T-fitting that came with the greddy gauge? When I installed my greddy gauge it moved around like that during idle. I bought a 1/4 vacum T-fitting at kragen for like 50 cents. and it helped it some. It'll still move around alittle, but not like bfore.

 

i used a 1/4 T bought it pep boys, doesnt move around at all i think