First my mods are as follows:
Apex PFC- base maps
DP
MP
N1 duals + Silencer tips
Stock intercooler
M2 intake
Turbos clipped and wastegate ported
I think that covers all applicable mods.

Anyways when I set the PFC to .80/.70psi I hold boost and get a good transition (very minor spike) to the secondary turbo. No creep at all. So basically running perfectly.

However when I kick the boost to .85/.85 I get a nasty spike at transition (.98) and the secondary boost is all over the place. What I mean by all over the place is that it pulses by about +1.5psi. It still does not seem to creep but that wavering scares me. It may creep but I do not stay into it cause I am worried about leaning it out at high RPM. I have played with the duty cycles for controlling the boost but they do not seem to help.

Could this be a problem associated to the poor boost control of the PFC or is it a bigger problem?

Any input would be appreciated.

Thanks,
Grant

 

Man! MP + N1 your car must be really loud. As close as you can get to running a straight pipe. I'm no expert but that is way too much flow and I would assume spike/creep would be pretty much guaranted even with a ported wastegate