low vac

[Mouse6933]

OK

sooo since i first got my car , its always had low vac(9.9) just finally got my new tps in ... and boost leak tested my car... It holds pressure fine... But still my vaccum is 9.9 never higher... Isnt it spose to be around 20??? Can someone help me out please....

myles

[S13240]

Should be in the -16 to -20 area. Did you hook up the boost gauge to the fpr vacuum line?

[ILikeMy240sx]

mine stays -20 sometimes -22.

are you running on aftermarket cams?

[Mouse6933]

this is my first turbo car... I had the swapp performed at xat i know that on the throttle body there are 3 vac ports... the large 1 smaller, and the one on the bottom... i know the one on the bottom gets capped off.. And mine are .. The large one go;s into a T one part go's to the boost controll valve( i bleeive thats what it is) and the other to the bov... The other side of the bosst controll valve go's to the actuator... Then the small one i guess is the feed to the boost controller???? and is also T to something above the throttle body.. i hope some of this makes sesne..

also only mods done are. fmic, Bov, exhaust, all those little supporting mods..

thnaks again everyone

myles

[ILikeMy240sx]

LOL... I had absolutely no idea what you just said...

But two coming from the intake manifold right by your TB.. one goes dedicated to BOV. The other goes to a T then splits to your boost gauge and your FP regulator.

For best response, your boost controller should be hooked up to your hot pipe (closer to turbo better)

Id take out the stock BC valve and replace with a manual BC or an electronic one.

[Mouse6933]

lol yea i confussed myself also. tomorrow ill take some photo's of what im speaking about or trying to speak about... and i have a greddy profec b....

[I ask good questions]

the profec b II never goes below -99 or -.75ish kpa i think. i have mine set on psi too.

[180fan]

kpa = metric, psi = standard units. it won't be on both settings.

[Mouse6933]

yea ive switched it , it is on psi now. and never higher than 9.9

[DRIFTINIZ]

LOL... I had absolutely no idea what you just said...

But two coming from the intake manifold right by your TB.. one goes dedicated to BOV. The other goes to a T then splits to your boost gauge and your FP regulator.

For best response, your boost controller should be hooked up to your hot pipe (closer to turbo better)

Id take out the stock BC valve and replace with a manual BC or an electronic one.

where is the stock bc located @???

[virus77]

if you are showing negative 9-10 psi on the boost controller gauge you are fine since greddy displays vacuum in psi. that equals -20 in.hg on a standard boost gauge (like autometer) since the reading on a gauge switches from psi to in.hg in vacuum (-20 in.hg is equal to -10 psi)

Your car is fine, stop screwing around and go drive the damn thing

[Mouse6933]

if you are showing negative 9-10 psi on the boost controller gauge you are fine since greddy displays vacuum in psi. that equals -20 in.hg on a standard boost gauge (like autometer) since the reading on a gauge switches from psi to in.hg in vacuum (-20 in.hg is equal to -10 psi)

Your car is fine, stop screwing around and go drive the damn thing

man that was funny as hell. Thanks alot for the help man just couble checking...