Boost Gauge Reading Wrong?

[BrOwnY GT]

]mines actually on +5 on idle...(auto) and jumps to 20 when i rev out its a mechanical cobalt series boost/vac gauge i just tap'd it into the line at the front of the manifold like described in a step by step posted on here i know its wrong coz my stock gauge sits in the - and jumps accordingly..

Edited May 31, 2011 by nismo07

[BrOwnY GT]

any idea's?

[GT32]

  On 31/05/2011 at 6:56 AM, nismo07 said:

any idea's?

Hmm, not sure. I've always tapped boost gauges directly off the plenum itself. Never really tried to tee it off an existing line. It definitely should be reading somewhere in the negatives on idle though.

Edited May 31, 2011 by GT32

[BrOwnY GT]

  On 31/05/2011 at 7:30 AM, GT32 said:

Hmm, not sure. I've always tapped boost gauges directly off the plenum itself. Never really tried to tee it off an existing line. It definitely should be reading somewhere in the negatives on idle though.

Was thinking maby trying it at the rear where the stock line goes in from the little box right near the brake booster? if i was to pull that off and run the gauge straight in be fine right? doesnt matter if i disconnect the stock gauge at all does it??

[GT32]

Nah won't matter if the stock gauge is disconnected or not.

[BrOwnY GT]

Ran the tube from the gauge straight into the plenum and still same result.. got me stumped maby my gauge is faulty or something from factory :S

[BrOwnY GT]

also shouldnt the gauge reset to 0 when the ignition is off? it sits on 15+ ??

[GT32]

Hmm, you could be right. Possibly a faulty gauge. I used to have an Omori boost gauge on my old 32. The gauge looked ancient! Was a mechanical type and I remember it was always 1-2psi out. When I had the car dynoed a few years ago, their dyno chart always displayed 1-2psi higher than what the boost gauge in the cabin displayed. It was probably due to wear and tear though. Is the gauge you're using brand new or second hand?

[BrOwnY GT]

  On 31/05/2011 at 9:04 AM, GT32 said:

Hmm, you could be right. Possibly a faulty gauge. I used to have an Omori boost gauge on my old 32. The gauge looked ancient! Was a mechanical type and I remember it was always 1-2psi out. When I had the car dynoed a few years ago, their dyno chart always displayed 1-2psi higher than what the boost gauge in the cabin displayed. It was probably due to wear and tear though. Is the gauge you're using brand new or second hand?

Brand new from autobarn was a cobalt autometer so thought it was quality rofl...

[GT32]

Hmm, could be faulty. Bring it back and exchange it for another one to see if it still does the same thing. I'm not even gonna bother using a conventional boost gauge this time around in my new car. Once my AVC-R goes in then I'll just rely on that from now on to show me how much boost I'm running. .

[GT32]

  On 31/05/2011 at 9:01 AM, nismo07 said:

also shouldnt the gauge reset to 0 when the ignition is off? it sits on 15+ ??

Sorry, didn't see this. Yes it should revert back to +-0 when the ignition is off. If it sits on +15 then there definitely is a problem lol.

[BrOwnY GT]

Yea what i thought lol ill return it tommorow and wait another 4 days another to come in lol... sigh... first time ive had issues with autometer though :S

[GT32]

Yeah Autometer is normally quite good. I'm actually using a mechanical Autometer boost gauge on my car at the moment and it's very accurate. Shame it's about to get ripped out though.

[BrOwnY GT]

definitely was the gauge lol... funny on the phone to them were trying to blame installation but once they actually looked at it they said "yea its stuffed"... lol dont know how it could be my fault when the needle resets to +15psi and wont go below 5+ anyways yea overnight delivery

[GT32]

Haha, I love it when retailers will firstly always try and blame the buyer or installation to try and cover their own arses. Whatever happened to good old decent customer service these days...

[Mayuri Krab]

  On 13/10/2010 at 10:59 AM, KnightRiderR33 said:

kool on another note what should the boost be reading on idle?? -7 like the stock gauge?

Different units, the stock gauge reads in mmHg x100 for both positive & negative pressure.

Most aftermarket boost gauge will read in inHg for negative & either PSI or Bar for positive pressure.

15 - 20 inHg is the norm for idling pressure with the car stationary, anything lower than 15 inHg & you may have a leak somewhere.

[Addicted2BoostR34]

anyluck ?