guys.. the ECU doesn`t throw a CELL if it reaches Max WDC...
only if it reaches limit BOOST.
tuning the wastegate with a 2 port WG is troublesome, especially when the spring is weak.
if the target boost is well within your turbo`s limit, the curve should almost always be nice.... as the wastegate behavior will nicely control it.
Problem arises when you play near the turbo max flow. Opening the wastegate juste a tinybit too much will have the turbo loose all it`s flow and will drop like crazy.
If your turbodynamics are giving too much adjustement, you will loose pressure when close to turbo limits..
not giving it enough might have you overboost if well under turbo limits.
A nice turbo curve will go a straight to desired boost or a little bit over with a smooth curve to level it back with NO waving.
If you have trouble reaching or eliminating waving:
1-make sure your wastegate is not sucked by a twin dump
2-make sure your wastegate is not pushed by high pressure the spring can`t hold
3-make sure your are not too close to turbo max flow
(you`ll have high pressure but too much heat which will reatard timing anywayz).
go GM BCS or lower boost a bit and play on timing to gain on torque