My boost gauge seems to be under-reading. The only reason I know this is because I hit fuel cut sometimes and my gauge reads just over 1 bar.

I've tried to check where the gauge is 'T'd into. There are 3 pipes coming from the top of the manifold (see pic (not my manifold, just a pic) below) -



The left hand pipe of the 3 goes to my dump valve. The middle has a T on it - one goes to the MAP sensor and the other part of the T goes underneath the intercooler to what looks like a smaller wastegate looking thing (anybody know what this is?). The 3rd I can't trace as I haven't a torch!

Anybody know what the thing I have described is under the left hand side of the intercooler?

Thanks!

 

i would of said it would go on the pipe on the left to the dump valve tho i may be wrong as i ant got 1 on mine lol

 

Anybody????

 

see http://www.scoobymods.co.uk/boostg01.htm

If your running a stock STi V2 ECU, your fuel cut limits are :
8.85
9.62
10.55
11.47
12.56
13.64
14.41
15.96

In theory these are staged limits, but in principle the limit is 15.96psi.
The lower limits 'Can' kick in under certain load/airflow conditions i.e a high gear pull from low rpm. Hence why a remap sets them all to the higher limit, to try and avoid this.

However 15.96psi is 1.1bar so you may well be hitting it. Alot of boost gauges under read a little, even the expensive Defi's