fuel pressure

Will the lowering or raising the pump loop jet raise system pressure.Whenever i have to fatten the motor alot and take boost away i can feel my high speed comming in and out{surging}.What is the best fix?We were in waco and had 920 corrected alt.I will not see this again all year but,need to know how to fix it.

 

Pressure changes

One would think so. If you put a bigger jet in, you're lowering the system pressure because you're taking more fuel away, and vice-versa. When one makes changes to a part of the fuel system, you must also consider what other effects it will have on the rest of the system.

Put a bigger jet in, and you will raise the RPM at which the high-speed will open, because the fuel pump must turn faster to produce the same opening pressure. If you don't want to change the RPM at which the high-speed opens, you will need to put in a weaker spring.

What else have you got in your system that will be affected by changing the loop jet/system pressure?