LLigetfa
DIYer, not in the trades
Most toilets do not rely on water pressure to flush, only gravity.
Have you done the flow measurements into a bucket as I suggested? It is premature to talk about pipe size if the shower valve is the limiting factor. Pipe size affects pressure only relative to flow. Right now, I suspect the shower head is the limiting factor.
Have you taken elevation into consideration? How much elevation difference is there between where the pump pressure switch is and where the shower head is? You can count on .43 PSI loss for every foot of elevation.
Have you done the flow measurements into a bucket as I suggested? It is premature to talk about pipe size if the shower valve is the limiting factor. Pipe size affects pressure only relative to flow. Right now, I suspect the shower head is the limiting factor.
Have you taken elevation into consideration? How much elevation difference is there between where the pump pressure switch is and where the shower head is? You can count on .43 PSI loss for every foot of elevation.