vacuum reading?

[subtlt]

I just got my Westach vacuum/boost gauge installed last night. What should my vacuum reading be? It's about ~19 cold idle neutral.

It's interesting to watch the readings, as with my cold idle stumble, you can watch them go from 19 to 0 then back as the engine catches. IAC reset time!

 

[scottyb]

I'd say that's real good vacuum. Mine does 15 - 16 idle, up to 20 coasting in gear.

 

[Roc87]

Mines only around 12in. at idle

 

[terryk]

Mines 10-11 at idle. Seems low, but the BLM's are 127 and it idles fine.

 

[UNGN]

Idle in neutral is meaningless. It could be reving at 1200 rpm. Idle at 750 should be about 12.5 or so.

 

[terryk]

10" at 650 RPM in Park.

 

[UNGN]

Originally posted by terryk
10" at 650 RPM in Park.

Thats a little low. if it idles at 650 in park, what does it idle in drive?

 

[terryk]

650-700 in PN or Drive. It follows the idle table vs temp closely.

 

[buickboy]

In drive warmed up 212/212 cam, idleing at 800-850, Vacuum is 15-16. Stock cam was 19.0
Mitch

 

[terryk]

Hmmm.....

 

[TurboDave]

I can tell you what I see. Idle in park/neutral at 800 rpm I see 17.5" of vacuum, and about 12.5 or so in drive (800 rpm).
I also use a Westach gauge, simply because I'm familiar with their calibration procedures and know their gauges are dead on balls accurate for vacuum and boost.
Not like the VDO's and Autometer's I've tried and had tested against lab standards.

 

[Jimn8or]

Stock cam = 18" 208/208 = 15" idle. Dave, funny you talk about Westach today...A board member here has their Boost guage which does the 3-5lb 'chicken' under boost. Westach suggested he do some 'McGyver' thing to the boost line, which he did...still does the chicken. Looks great, but don't hear the same vindication about Westach from this guy...
Jim

 

[TurboDave]

Originally posted by Jimn8or
Stock cam = 18" 208/208 = 15" idle. Dave, funny you talk about Westach today...A board member here has their Boost guage which does the 3-5lb 'chicken' under boost. Westach suggested he do some 'McGyver' thing to the boost line, which he did...still does the chicken. Looks great, but don't hear the same vindication about Westach from this guy...
Jim

What's "chicken"?????

 

[terryk]

I believe it's techno-babble for "goofy".

 

[Jimn8or]

Flutter/shudder/flucuation...chicken

 

[Two Lane]

As in: "The gauge is doin' the funky chicken!", which is quite a vigorously energetic dance from the '70's disco-daze.

HTH

 

[TurboDave]

OK, now when put in plane english, I see the picture ;-)

Here's the oddity, many boost gauges like autometer, and vdo are VERY prone to do that. The reason is, Westach is one of the rare ones out there that uses dampening in the gauge to minimize this from happening.
That, and their calibration is the reason I switched.

Some of the things that can cause this 'chicken' as you like to call it, are too long of a run to the gauge using hose materials that tend to flex too easilly. That's the reason hard plastic lines are ideal.

If you must use rubber vacuum hose, one thing to try would be to change over to some extra thick wall stuff. That should solve the problem, if not, then plastic. And after installing hard line and you still have the problem, it's something else, not the gauge.