11 replies to this topic

[Start]

Hey guys,

Possible noob question...

Just installed a boost guage in my suby, and noticed at idle it sits at -20psi vacuum?

I thought it would sit at 0, would this mean I have a vac leak?

Car boost's fine, up to 14PSI in this heat..

IN B4, bad location, ABS Light On, Auto Cluster... etc

[Soop]

Normal .
Engine is sucking air, its a massive air pump. It will reach 0psi when the turbo begins to spool. 0psi means there is an equal amount of air being forcd in, as there is being used.

[Start]

Champion

Thanks mate, saved me from having a heart attack.

[Soop]

LOL, fair enough.

Did you think the turbo was in reverse or something??

[Start]

Pretty much LOL..

Remember'd my brothers car always being positive on the guage.. mustnt have ever looked when he was idle.

Thanks for the quick reply, ill rep u when i figure out how..

[Alex]

its not -20psi.

its 20 mmHg (millimetres of mercury). A standardised unit of measure for suction.

Also, your motor is rather healthy and has good compression.

If you notice it drop (except when you're at the lights with the brakes on, with the aircon on, when the engine's warming up from cold) it means you're dropping compression.

ie: vacuum leak, potential engine damage, etc etc.

Boost gauge is a very handy gauge, not just for positive pressure

[B4TT]

its not -20psi.

its 20 mmHg (millimetres of mercury). A standardised unit of measure for suction.

Also, your motor is rather healthy and has good compression.

If you notice it drop (except when you're at the lights with the brakes on, with the aircon on, when the engine's warming up from cold) it means you're dropping compression.

ie: vacuum leak, potential engine damage, etc etc.

Boost gauge is a very handy gauge, not just for positive pressure

This utterly truthful post needs rep~!

[Hypnotic]

its not -20psi.

its 20 mmHg (millimetres of mercury). A standardised unit of measure for suction.

Also, your motor is rather healthy and has good compression.

If you notice it drop (except when you're at the lights with the brakes on, with the aircon on, when the engine's warming up from cold) it means you're dropping compression.

ie: vacuum leak, potential engine damage, etc etc.

Boost gauge is a very handy gauge, not just for positive pressure

Cheers for that info Alex, might be a good thing to have on the B4.

[Alex]

Whoops.

unitFAIL.

its not mmHg. Its InHg.

inches. not millimetres.

still mercury though!

apologies.

[Jimbo]

Jamie, did you sort out the TT problem at all mate?

[Start]

Hey man,

yeah my mate did what you said, tapped into the other line to bypass the valve.

It appears to be working it pulls alot better and the second turbo now comes on hes happy with it.

Cheers.

[Jimbo]

sweet, he must be thrilled. That little trick works a treat!