What are the cons on running 50-55 psi fuel pressure?

 

I didn't really witness any ill effects while running 55psi base in my car... It ran this base FP after rewiring a single walbro 255...

 

No cons, but if you are intentionally trying to run higher pressure, you may find that it does not provide any additional fuel because pump fuel flow decreases as fuel pressure goes up. depends on the pump setup and boost level.

 

you need to determine the ultimate boost you want to run and then add that to the base pressure. So, if you want to run 30psi then you would need to see how the pump will flow at 85psi (55psi + 30psi). Pump flow decreases with an increase in pressure so be mindful of this. If you are starting from scratch and have to retune regardless then set the base pressure to ~43psi, which gives you a total pressure of 73psi. You will get much more flow from your pump at 73psi vs. 85psi.