How many lbs of Vacuum do you have at idle???

[b_dolla44]

So I just got done swapping my Riva gen 1 IC out for a XS type 3 IC. I also installed a Jlewis gauge pod(), and a AutoMeter Phamton boost gauge.
I fired it up, and I'm only seeing 10lbs of vacuum at idle....
This seems low...
But I only let it run for 15 secs or so....
My question is...
A). How many lbs of vacuum do you see at idle?
B). Is there a idle air control valve?(if so, that would explain the low vacuum)
C).If there is a idle air control valve. How long does it take to close????

[BigDaddyRXP]

Only 10 lbs. I've never seen more than 4-5 lbs. vacuum at idle... on a digital dynotune gauge.

[b_dolla44]

Only 10 lbs. I've never seen more than 4-5 lbs. vacuum at idle... on a digital dynotune gauge.

WHEW!!!What a sigh of relief.... I was used to my Turbo/NA drag car engines. (25-35)lbs of vacuum....

[boostaholic]

I see around 10 in/hg as well

[Trond]

WHEW!!!What a sigh of relief.... I was used to my Turbo/NA drag car engines. (25-35)lbs of vacuum....

Hmmmmm.... If you see more than 14,7psi of vacuum, then you have broken the law of fysics!!
Its not possible to have any lower than 0 bar (-14,7psi).... the atmosphere is 1 bar (14,7psi).

[R88ory RXP]

WHEW!!!What a sigh of relief.... I was used to my Turbo/NA drag car engines. (25-35)lbs of vacuum....

vacume is measured in IN/HG not PSI

R88

[Vern]

This is a good question and can indicate a number of issues with a motor ... after I got my cam timing right, I am seeing 11 - 13 inches of vacuum at idle. I wish I would have checked vacuum when I was off a tooth, but I suspect it would have been much lower. I would like to hear what others measure on their skis too ...

[Snoman]

My ski i am seeing 10 on an autometer mechanical guage..On my wifes i am seeing 7.5-8 with a dynotune guage

[b_dolla44]

This is a good question and can indicate a number of issues with a motor ... after I got my cam timing right, I am seeing 11 - 13 inches of vacuum at idle. I wish I would have checked vacuum when I was off a tooth, but I suspect it would have been much lower. I would like to hear what others measure on their skis too ...

Vern,
I remember back in the day when I used to play with turbo Honda's (B series) If you had a "low mile" well taken care of B series it would make "30ish" inch's of vacuum...
I remember making a test run at the strip. When I hit 4th gear I looked over at the boost guage to see that it was buried in the 30+lbs of boost......(car was only tuned to 15lbs)..By the time I realized i had a major problem it was to late... The Tial wastgate I was running had a Ebay diaphragm in it and broke...causing a huge boost spike... When I let out of it, and got the stopped I looked back over at the boost gauge to see that it wasn't making any vacuum at all...(oops)...Long story short. Vacuum can be a great tool when checking for problems....

[Vern]

Ouch! That would not be a good day! Zero vacuum = expensive repairs ... bummer.