Boost gauge question
- Thread starter richyrich
- Start date
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Ultralord
Well-known member
aem makes some nice stuff they also make a true boost gauge that has adjustable boost control on it.http://www.aempower.com/ViewCategory.aspx?CategoryID=68
You don't need the vaccume, just boost is fine. you may want to look at glowshift's digital gauges, I just bought one, they are really cheap, so I'm skeptical, but it's a digital boost/vaccume gauge for only $70. I haven't had a chance to install it yet, but it seemed like a pretty decent deal to me.
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sled-fiend
Well-known member
Are you running that gauge on your sled? Looks sweet! I wonder if it would be a pain to remove my existing boost gauge and boost controller and add that?
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EZmoney
Well-known member
Richy the autometer is your best bet in my opinion, its a simple gauge with no electronics to fail like the aem.I have a aem a/f gauge and i got the back siliconed up and it still gets moisture in side,and i have to dry it out once in a while. But has not failed yet.The only thing i do not like about my boost gauge is the size. Its only a 2'' and hard to see some times on some pulls where you cant look down long enough,where a little bigger one would be more user friendly.I hope this was some help. 
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richyrich
Member
What I will have is the stock gauges, Innovative a/f and an Autometer liquid filled boost. I want to mount the boost below the mountain bar but haven't found a good bracket yet. I like Cr Racings billet boost gauge bracket, but not sure if it would work with the stock apex riser as it mounts to the bars. ??
"Vacuum" is a good indicater of an intake leak...... I like having vacuum on my gauge.
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modsledr
Well-known member
Hey Sap,
would an intake leak actually show up as a vacuum reading on the gauge? Or would it just have less boost?
The gauge is just a pressure/vacuum sensor, so in order for there to be a "vacuum" reading, that would mean no boost at all (or technically negative boost).
Am I thinking about this right?
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richyrich
Member
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Ultralord
Well-known member
When the engine is healthy and working correctly, at idle the needle of the gauge should be steady and within the range of 17 – 22 inches of mercury.
Normal Engine when Throttle Snapped Open and Closed
Vacuum should drop to 3 and then momentarily climb to 25 – 28 before settling back at the previous value. This indicates that the valves and rings are OK.
Poor Rings or Oil at Idle
The needle will be steady but the reading will be lower than normal.
Poor Rings or Oil when Throttle Snapped Open and Closed
Vacuum will drop to near zero and then momentarily climb to about 22 before settling back to previous value.
Sticky Valve
The needle will drop occasionally about 4 inches of mercury from its normal idling reading.
Burnt Valve
The needle will regularly drop by a greater amount than with a sticky valve – eg 6 inches of mercury.
Leaky Valve
The needle rapidly drops two or more inches each time the valve should be closed. May also indicate a misfire.
Loose Valve Guides
Fast vibration of the needle between 14 and 19 inches of mercury.
Weak Valve Springs
When revving the engine hard, needle varies between 14 – 22 inches of mercury. As rpm increases, a wider variation occurs in needle movement.
Leaky Intake System
Needle reads low (eg below 5 inches of mercury) at idle. May also indicate late ignition timing or incorrect camshaft timing.
Leaky Head Gasket Between Cylinders
Needle floats regularly between 5 and 19 inches of mercury. May also indicate intake manifold gasket leak at an intake port or a faulty injector.
Blocked Exhaust
High reading at first but suddenly returns to zero then builds slowly back to about 16 inches of mercury.
Clogged PCV or Intake Manifold Leaks
Needle moves slowly through a wide range of readings. Also check idle air/fuel ratio.
Conclusion
Obviously vacuum gauge readings cannot be definitive, but they can save a you a lot of time and money in chasing down obscure problems.
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That almost looks like a Hammer post!!
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powderlites
Well-known member
vaccum leak
When guys phone us and have low vaccum then we know that cam timing wrong or valves too tight etc also.
Blowoff valve leaking from a bad diaphram or installed wrong.
Just a few things to help you out when throttle bodies or something goes wrong. So good gauge is nice.
http://www.powderlites.com/boost%20gauge.jpg
When guys phone us and have low vaccum then we know that cam timing wrong or valves too tight etc also.
Blowoff valve leaking from a bad diaphram or installed wrong.
Just a few things to help you out when throttle bodies or something goes wrong. So good gauge is nice.
http://www.powderlites.com/boost%20gauge.jpg
Is the gauge in that pic the one you send in your kits it looks nice.
