cp-e has reconfigured the Standback to use the CAN data from the DME in the tune. This was not possible before as the processor that the standback uses was completely maxed out and had no more capability. The chip manufacturer however, recently updated that item and now it has more capability with the same coding allowing Lou, cp-e's genius EE, to add CAN functionality to the Standback. We hooked up the BT tool to my car and he "listened" in on the transfer of the target boost data. He then emulated that process on the standback such that the it can now open a CAN session and request the realtime target boost of the n54 DME. He then spits this information back to the DME while independently controlling the wastegates. THe result is a completely open throttle, a completely happy DME, and COMPLETE boost control.
Before this the standback took over boost from the DME at boost greater than 5 psi. At values lower than that the Standback gave the car what it wanted. This was no small feat considering that the Standback was in complete control of the wastegate solenoids.
With the new CAN data it can take control at much lower boost pressures. The standback now assumes control at 2 psi which is just slightly higher that cruise. This coupled with the 30x30 boost control table allows for extremely fine control of boost pressure and immediate response. The following are my boost map followed by graphs from a log I took on this morning's commute.
These first three graphs show the excellent boost control. Depress the accelerator a slightly, get a little boost. Press slightly harder, boost increases in a controlled fashion according to the boost map above. These stairstep like boost graphs are the result of me depressing the accelerator more and more and finally all the way. It demonstrates how controlled the boost is.
My tune uses RPM vs MAP for the fueling and timing. At each boost level and rpm there is a specific fueling and timing parameter programmed, e.g. at 10 psi I pull 1 deg of timing and add 5% fuel (subtracting 5% from the wideband signal so the car adds fuel). At every point on the graphs my fueling and timing are controlled with respect to the rpm and boost.
Mat it and you get max boost and open throttle.
It is truly remarkable. Instant control without any DME weirdness. The car is ultra responsive and hasn't lost any driveability whatsoever. THe map is completely customizeable so you can literally make the car do whatever you want.
These same map tables exist for fueling, timing using cps offsetting, meth addition (yes, the SB will control a meth pump and has failsafe algorithms), and fuel pressure.
It may be somewhat late to the game but, it truly is the state of the art for controlling the n54.