My vacum reading is at 20psi when idle, and when moving at 23psi. Anyone else have numbers like this.. I believe its Psi.. thats what the crappy pepboys meter i got says...

heh, mine is 11-10, but i have 272 cams, 18-20 in/hg is normal

Hi,

I going to move this to the Evo Engine/Turbo forum. Your gauge is not connected properly or it is defective. You should be reading a vacuum at idle which will depend upon stock or aftermarket cams.


Sorry Nastea, didn't see your response until I posted.

Speedlimit...

I find it interesting to see how much boost is affected by turning the AC on. IIRC mine goes from -13 to -8. 5lbs difference just from the AC.

I ahve the EVC V. WHen starting the car, I get -17 at idle. after driving a while, I get -22 at idle.

about -25 at idle

-20 to -23 in/hg here.. cams with increased overlap will cause the vacuum at idle to be alot lower.. also when the engine is cold there are a few timed vacuum sources and also raised idle speed with the idle control motor, so its going to be a little lower.. also when the AC is running it will affect engine vacuum, basically lower engine speed.. HOWEVER after you run the car a few times with the AC running, it goes back to normal..

Between 15-20 at idle, depending on engine temperature...

im about 15-20 also that seems to be the norm. does it also depend on what climate you live in?

I think it will vary a little based on climate.. denser air in cold climates means higher boost, so it likely would result in slightly less vacuum.. (Does that sound right??)

Though I don't think it would vary by much since I've never noticed a difference on really cold days, and really hot days (when the car is at operating temp)

I was just about to ask about this...I'm glad I'm not the only one

10-20 for me and I have 272/272 cams

i am around -20 at idle with the ac off.