false. i have a tee on the main feed line right before my stock returnless rails, the tee goes to the fpr, then out the bottom of the fpr, the return line goes back to the tank. this way, anything before the fpr has the same pressure. and also i have an in cab fuel pressure gauge that gets its signal right on the fuel rail crossover and this setup hasnt proven ineffective at all at 15psi, 700hp.

 

that make sense .that how the BG 400 ON our race car is designed .that way fpr make sure fuel rails are full (set pressure) before returning to the tank.