I've posted about this before, and i've also posted it over in the B5 section, but since the AJL is similar to the AGU i figured someone here might have seen this before.
So, i've noticed this oddness when driving the car hard, in that theres a lag after a gearchange.
So you go full throttle thru 2nd gear to say 6500rpm, change to third and go full throttle again, and the car starts to accellerate, then after a moment, perhaps 0.5-1seconds, it starts accellerating harder.
Today i noticed that if you watch the boost guage when this occurs, the needle quickly flicks round to 5psi, and sits rock solid on 5psi for this 0.5-1sec period, then it sweeps round to 10-12psi and the car stars accellerating more. So clearly its not mechanical lag, as the fact the turbo hits 5psi instantly suggests the turbo has spooled instantly but the wastegate has simply opened at actuator pressure.
This in turn suggests its as though the ECU itself isnt requesting boost quick enough...
I first noticed this ages ago on the Avant, and put it down to the old turbo being a bit shonky, however i've started noticing shed does it as well, and avant still does it with its new turbo.
First off does anyone else have this phenomenon, and if not, any ideas of the cause?