Vacuum/Boost gauge operation

[SrS13]

I was wondering if my gauge was operating properly:

At idle it reads about 20 if I'm crusing it its below any boost levels.

I was wondering if that is normal

thanks any help is appreciated.

[big jon's 240]

if I'm crusing it its below any boost levels.

HUH???If you mean that you are running 20 (vaccum) at idle, then yes that is normal. I dont understand the second half of your question.

[SrS13]

sorry I ment to say that when I am at a crusing speed my gauge does not mark any boost pressure it remains in the vacuum side.

[SWIFT_DRIFT]

is it a mechanical or electronic boost gauge and does the needle even move at all? more info please

[SrS13]

yes the needle moves towards the 0 but stays just below during crusing speeds. Im just wondering if that is normal??

and it is a mechanical gauge

[Tai Mai Shu]

yes it is, for me to maintin a constant speed I usally am at 11 vacumm, but give or take.

[BuudWeizErr]

-10 is about normal. Give or take a couple.

-18 at idle is normal. A little more if you have cams.

[ucfz31s13]

You wont produce any boost until you reach certain throttle % to create enough exhaust flow to begin spinning those blades. Cruising you are barely on the throttle so it will still pull a vacuum on the gauge...

And BuudWeizErr: Isn't that backwards? I was always informed that cams decreased vacuum at idle because motor loped more?

lataz

z

[SrS13]

kool this is exactly what I needed to know Thank you Very Much

[BuudWeizErr]

You wont produce any boost until you reach certain throttle % to create enough exhaust flow to begin spinning those blades. Cruising you are barely on the throttle so it will still pull a vacuum on the gauge...

And BuudWeizErr: Isn't that backwards? I was always informed that cams decreased vacuum at idle because motor loped more?

lataz

z

I could be wrong, but I think I'm right.

[big jon's 240]

The amount of vacuum does depend on the cam, if you have a cam (aftermarket) with more overlap, you will have less vacuum, and vice-a-versa. Ive never heard of too much vacuum, the more the better, means everything is healty.