I've recently completed a rebuild of a 1.8T with a number of upgraded goodies including a built bottom end and a new turbo kit (PPT). I'm beginning to move on from fueling on this Stage 3 tune and I'm run into a bit of a snag while tuning and setting up boost control. I'm unsure at this point if my problem has to do with tuning or hardware but let me explain.
I've used the following boost line configuration for the Tial wastegate which seems to be pretty standard:
My issue is that I do not have any boost control whatsoever. The boost skyrockets past 30PSI immediately regardless of what I've tried, other than just running directly off of wastegate pressure which is about 14.5 PSI. In any other configuration, there seems to be zero control.
-I've tried setting KFLDRL to 0 across the board (as a control test). I expected this would effectively be the same as running off of wastegate pressure. No effect. However, since the positive pressure is constant (or should be) at the bottom of the wastegate valve, shouldn't I be inverting KFLDRL to run a high duty cycle (bleeding off 95% of boost)?
-So I tried setting KFLDRL to 95.0 across the board. Again, no effect. Surely one of these two configurations should have *some* effect on boost control. But no. Zero, zilch.
-Then I tried placing a MBC in place of the N75, turned all the way down. This should allow no flow to the top of the wastegate valve. Again, no effect.
I assume it's safe to say that my problem is hardware related somehow? But how? The wastegate operates normally at 14PSI until it's connected to something on the top of the valve.
I have logs, but they're generally useless. They just show what I've said above. Any ideas?