Boost gauge problems

[James TQ]

I fitted a manual gauge today and it sits normal when the engines off when the engine is running the gauge is way below the - on the scale ad when on boost it Dosnt make 0.5 on the scale? Car is a 99 a3 Quattro Jetex filter fmic 008 DV I teed the vac pipe on the fpr line, any ideas?

Thanks!!

 

[badger5]

0.5 what?
what units?

 

[James TQ]

Bar I presume?

 

[James TQ]

Faulty gauge maybe?

 

[Dani_B19]

So what does the gauge read when idleing? Also is the car remapped? Btw change the feed from the fpr to the dv, if theirs every a boost leak from that area due to rhe t piece itll **** your fueling up.

 

[jimmcgee]

Faulty gauge maybe?

1 BAR is 14psi so your gauge is never going to go over .5 , unless its chipped .

 

[James TQ]

When it's on idle the need is pointing south.... Straight down, then when I rev it rises car isn't mapped and yeh I'm sure there's no leaks check and replaced a fair few pipes. It's only a cheapo gauge from eBay but just worried the vac is too strong or somthing

 

[badger5]

sounds like a shyte gauge

 

[Jumble]

What boost should a standard car run at. I have monitoring mine on Torque but have been getting some quite bizarre readings. Was going to get a mechanical gauge to see what readings i got from that.

 

[badger5]

i see -0.7bar on idle on a stack boost gauge, and -9.3psi on my dyno logger on idle

*guide*

 

[James TQ]

What should a stock a3 Quattro run any ideas?

 

[badger5]

the same - its idle

 

[Dani_B19]

My s3 idles at -20pis on my stack gauge!

 

[badger5]

wow thats too high to be plausable unless you idle at 2krpm

 

[s3dave]

Mine is -20 IN HG too normal idle..

 

[badger5]

inaccuracies of pressure gauges in vacuum I guess....

 

[s3dave]

Hmm i thought this so i swapped for a pro sport Digital and reads exactly the same... Is that to high then Bill?

 

[Jumble]

Just been out and taken an idle reading from mine using Torque app and getting around -22in/hg

 

[Prawn]

Mine's the same, around -20 on the gauge on idle. All the 1.8T's I've seen have been on various different gauges too.

James, an unmapped TQ isn't going to be making much boost anyway, the turbo is more of a paperweight than a boost in power. I think stock boost is around 10psi which is around 0.6-0.7 bar.

 

[James TQ]

Ill wait untill I get a new gauge. What if there's too much vac what's the cause of that?

 

[badger5]

why are you fretting about vacuum????

 

[superkarl]

OP doesnt mention units at all. so how can we advise.

vaccum is measured in Inhg, which is inches of mercury at 0 degrees C. thats what should be on your gauge on the vacuum side of things. You should read about -20, or there abouts. 1inhg = 0.49psi btw, incase your gauge reads psi.

boost is as prawn says.

and dont take the vac off the fpr

 

[James TQ]

Ok so I got a new gauge, it won boots past 0.25bar? It's an un mapped as TQS eBay fmic Jetex filter forge 008, Is this low? Gone over all pipes no leaks? Other things to look for?

 

[pinci]

Mine Defi boost gauge in idle it runs at -0,7 or -0,8 in vacum...Arround 3000 rpm's the pressure is out of vacum and the car is starting to boost....A3 TQS K03S remaped at full boost around 1,2 bar...In overboost it goes arround 1,3 or 1,4 bar and in some time around 6000 rpm it falls down to 1,00 and 0,9 bar's

 

[James TQ]

so mine standard isnt making 0.5bar?... this is low? any ideas why?

 

[pinci]

Where you have fitted T clamp and vacum hose for the gauge ?

Maybe the gauge is ok and you installed it properly...Have you tested maybe boost leak or something...Car goes normally ?

Stock boost I think is about 7-9 psi depends od air temperature and humidity....That aprox.. 0,5 -0,6 bar's ...The gauge readings is in your case correct

 

[James TQ]

I t'eed it of the fpr iv gone over the engine so many times looking for leaks ad found none :/ just 0.25 bar seems low boost?

 

[16Klappe]

This thread hurts my brain.