I've spent a while searching for an answer to this but found nothing yet...
As I understand it, the boost produced by the first turbo should go up to and hold at 0.7 bar until the engine reaches 4000 rpm when the second spools into play.
What I am looking for is a description of how the first turbo comes in, e.g. at what engine speed does it start boosting and by what engine speed does it reach full boost?
I ask this because I believe mine is boosting particularly weakly. For example, if I cruise at 2000 rpm in third then open the throttle, there is no spooling sound or movement of the boost gauge until at least 2500 rpm, maybe 3000 rpm. After this the boost increases fairly linearly (although sometimes there are oscillations of around maybe 0.2 bar superimposed on this, intermittent) to around 0.5 bar at 4000 rpm. Of course, after this the second turbo comes online and the boost raises quickly, and peaks at 0.9 bar.
For reference, the car has a second decat and a custom 2.5" decat back exhaust. Also, pulsing the throttle with no load on the engine never results in any boost; the BOV makes no sound. BOV operation is normal when driving under load.
Am I entirely mad in thinking my car is a little less responsive than it should be?
Thanks for any help guys!