[grivera]

Is the situation different for EFI? With an in-tank EFI pump is the goal to maintain the fuel pressure required at the throttle body and sizing the fuel line to meet said PSI?

[PunchT37]

You’ll be borderline on the street. Upgrade if you hit the track. My old 470 ish hp 455 did well on the street. At the track, it would pop through the air cleaner just before the line at the top end. Pulled the plugs. All white like a bed sheet.

[Formulajones]

Originally Posted by grivera

Is the situation different for EFI? With an in-tank EFI pump is the goal to maintain the fuel pressure required at the throttle body and sizing the fuel line to meet said PSI?

I don't have a bunch of experience with EFI at the track other than racing LS engines back in the 90's and early 2000's. All those vehicles had smallish factory fuel lines, but they also pump 58 psi fuel pressure too. I ran them into the 11's and near 120 mph without issue but I did upgrade the factory in tank pumps. Others were going even faster with them back then.

Pressure is one thing, volume is another, I'm sure you're aware.

Whether it matters or not, when I'm doing a moderately high HP EFI build, I just run the 1/2" lines to and from and be done with it. One reason is because I'm typically replacing fuel lines on a build anyway, so I just upgrade to 1/2", the cost is the same.

Ironically both of our current EFI cars (one running 10's and the other 11's) already had 1/2" lines and in tank pumps when they had carbs, so all of that was left in place when the switch to EFI was made.