Boost gaugeb reading
03 Cobra Killer
Joined: Jan 2002
Posts: 1,423
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From: All Over
I donno if that is good, or good enough, I just know that when I read other threads on idle vacuum the question was always asked what the idle RPM was when they were looking at the vacuum reading, figured I would at least help you get more helpful information out there so the pro's could toss in their 2cents.
K
K
Full Member
Joined: Feb 2002
Posts: 148
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From: Salisbury N.C.
I'm not one of the pros, but hear that 15 to 20, is good. Seems that would show overall good health of the system. Such as your vac. lines and all. A sudden change would indicate problems, and you would check accordingly. At idle, i show about 19lb. I may be wrong, and I've got a lot to learn, but I've had mine for about a year and a half now, and I've never had any trouble.
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Idle vaccum readings are not measured in lbs/psi, that would indicate a positive reading.. ie. something under pressure. Vaccum is measured in Hg, the metric scale is something else.. can't think of it off the top of my head. I think 15Hg is a little low but it could be a lot of things other than bad compression.. vacuum leakage, gasket leakage, high idle, bad plugs, timing.. etc.
Matt
93 SSM
Matt
93 SSM
Originally posted by FstFD3SPOWER
high is good right?
today when i started the car hgmm was 15-16... and when car got warmed up it was 15..
Removing air pump matter? recently i removed air pump.
Thanks
high is good right?
today when i started the car hgmm was 15-16... and when car got warmed up it was 15..
Removing air pump matter? recently i removed air pump.
Thanks
Is your engine stock or street ported? 12-15 would be normal for a street port. Non-ported should be around 16-19.
Idle should be about 16 - 18 in Hg.
Max boost should be about 10 PSI (for a stock car).
________________
Date: Thu, 29 Jun 2000 16:36:11 -0700 (PDT)
From: RETed (reted_2000@yahoo.com)
> My car idles at about 750 RPMs. Is the vacuum reading a sign of how
> aggressive the porting is?
Yes.
* Normal stock motor will show 18" or better.
* Mildly ported motors show 14"-16".
* Heavily ported motors can go down to 10"-12".
Max boost should be about 10 PSI (for a stock car).
________________
Date: Thu, 29 Jun 2000 16:36:11 -0700 (PDT)
From: RETed (reted_2000@yahoo.com)
> My car idles at about 750 RPMs. Is the vacuum reading a sign of how
> aggressive the porting is?
Yes.
* Normal stock motor will show 18" or better.
* Mildly ported motors show 14"-16".
* Heavily ported motors can go down to 10"-12".
Lives on the Forum
Joined: Dec 2001
Posts: 14,716
Likes: 10
From: San Lorenzo, California
Originally posted by RedFD
I got 25-27 last time i checked
I got 25-27 last time i checked
Originally posted by SanJoRX7
My newly installed Defi shows me at about 20 mmHg at idle. I have a pretty perfect boost pattern and the car runs fine, so I'm assuming that it's ok.
My newly installed Defi shows me at about 20 mmHg at idle. I have a pretty perfect boost pattern and the car runs fine, so I'm assuming that it's ok.
Originally posted by FstFD3SPOWER
hehe.. mine isn;t ported yet..
but i get 16 vacuum.... ... ... .... .. .. ..
hehe.. mine isn;t ported yet..
but i get 16 vacuum.... ... ... .... .. .. ..
Senior Member
Joined: Mar 2001
Posts: 492
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From: SF
Originally posted by FstFD3SPOWER
What kind of problem i might have?
What kind of problem i might have?
Senior Member
Joined: Mar 2001
Posts: 492
Likes: 0
From: SF
Originally posted by FstFD3SPOWER
i god autometer gauge btw... are they accurate?
on my avc r it says 480mm/hg/.
i god autometer gauge btw... are they accurate?
on my avc r it says 480mm/hg/.
Senior Member
Joined: Nov 2001
Posts: 508
Likes: 0
From: Manassas, VA
Originally posted by rynberg
I don't think it is possible to pull that much vacuum. Are you sure your gauge isn't marked in cm of Hg? 25-27cm would be 9-10 inches of vacuum.
I don't think it is possible to pull that much vacuum. Are you sure your gauge isn't marked in cm of Hg? 25-27cm would be 9-10 inches of vacuum.