Boost gauge question

[jon_91_s2]

Sorry if i being a bit daft

Finally fitted my boost guage yesterday. Nice and easy to do(thanks to this forum) At tickover it reads -6 bar???? Is this correct(doesnt make sense to me) Its connected to the pipe which comes off the ecu by the way.

A mate suggested that it would settle down after a good run. Well shes had a good run this morn and no change.

Confused

Any ideas guys?

Cheers

[Pisobiker]

You probably mean -0.6 bar?

If it's that, everything is fine.
Consider at idle and/or closed throttle, cylinders are still trying to suck a volume of air almost equal to the displacement. Problem is throttle plate is closed thus generating a fairly high vacuum in the IM (and boost reading for the ECU is taken from it).

So you should see -0.6 bar (relative; or +0.4 absolute) at idle, while even -0.8 when shutting down throttle at higher rpm.


Marco

[S2 Ant]

Was about to post this sounds right as it runs as a vacuum on tickover, only when under load and giving it some beans will it go in to boost

[jon_91_s2]

Yup its -0.6 Doh!

Thats ok then

Cheers Marco

[S2central.net]

Yep expect ~0.5bar vacuum at idle and ~1bar vacuum on overrun.

More importantly - what does it read at maximum boost from low revs in 4th gear ?

Should be 0.8bar boost for a healthy 3B or 1.2bar for a healthy ABY - factory chips in either case of course...

Paul

[juleshh]

Hmmm

Yep expect ~0.5bar vacuum at idle and ~1bar vacuum on overrun.

More importantly - what does it read at maximum boost from low revs in 4th gear ?

Should be 0.8bar boost for a healthy 3B or 1.2bar for a healthy ABY - factory chips in either case of course...

Paul

Hmm,

Mine boosts to abt 1 bar on max and sometimes 1.1-2 on max and it is a stock 3b [I have a guage]

That's good I guess.

Paul, will be in touch soon abt a HF.

J

[S2central.net]

Jules - Someones chipped it before you and/or ******ed about with the WG spring !


Paul

[jon_91_s2]

Not sure yet but only driven it to work this morn. Will give it a test on the way home. Pretty sure I still got a boost leak somewhere. How much does the MAF to turbo hose affect boost(mine is split but new one on the way from VAG parts)

Cheers