Correct boost gauge operation???

[ninjinski]

Just finished fitting my boost gauge and its operating as such (and I just wanna check its working as it should) I'm not convinced!

On engine off the gauge sits just below the 7psi mark - On start-up it drops to 0 psi - then on flooring it it can hit up to 12psi  s:!: :!: s:!:  

Signed confused - as i thought it would never go over 7psi, or maybe Im simply wrong  s:!: :!: s:!:

[aaronjb]

That sounds broken..

At idle you should see vacuum (negative numbers, depends on the scale of the guage - some are psi, some are mmHg, -10psi or -22mmHg seems normal), then on boost whatever the TTE runs.

Sounds like your guage thinks 7psi is 0psi...

[spit]

I'd go along with that ..... but why it then goes up to 12 is a bit of a stumper  s:shock: :shock: s:shock:

[markiii]

not so sure

the VDO doesn't do negative readings IIRC so when at idle it should read zero, if it sticks at 7psi when off, that may be a feature, as long as it zeros when you start the engine I wouldn't worry about that one.

However, the 12PSI suggests boost creep. what exhaust are you running?

[aaronjb]

I'd go along with that ..... but why it then goes up to 12 is a bit of a stumper  s:shock: :shock: s:shock:

I dunno - kinda suggests to me that it simply drops to the bottom of the guage when off, thinks 7psi is 0psi, and therefore when it's reading 12psi you're really pulling 5psi..

Which sounds more likely for the TTE..

A real 12psi on the standard injectors and TTE management would likely have lead to a toasted engine by now IMHO.

[ninjinski]

not so sure

the VDO doesn't do negative readings IIRC so when at idle it should read zero, if it sticks at 7psi when off, that may be a feature, as long as it zeros when you start the engine I wouldn't worry about that one.

However, the 12PSI suggests boost creep. what exhaust are you running?

Mark running the TTE exhaust - Explain creep Mark please!

edit **Boost creep is rising boost due to not enough exhaust bypassing the housing** edit

[ninjinski]

I'm actually going to unscrew the connections at back of gauge and reattach to see it that balances the pressure.

NOPE didnt work  -  seems to be very happy at 7psi when power is off almost as if it needs to be reset to 0. On turning on the engine the vacuum pulls it back to 0 then on blipping the throttle itll shoot to 7 and on boost upwards of that - very strange!!

Still dont think it right as its working like a gauge with minus numbers but without  s:? :? s:?