Do you have to change the injector bias on a 7747 ($42) to the same value from the BigBlock bin when upgrading injectors? The reason why I ask is that there is ALOT of fuel at idle splashing back and my O2 mV are in the .900 range. I have he BPW set at 81 as I am running 18 lbs of fuel pressure.
I am finally trying to give this motor what it wants, more fuel!
WB shows lean on AE WOT with the old setup....as you would imagine it should be with 55pph injectors @ 11 psi! I found my old regulator wouldn't go over 11 psi even with an upgraded spring. My guess is to match the injector bias to the value in the BigBlock bin as the open time should be shorter, right?!?

 

So, I re-read the stickies and searched about the inj bias. It seems my thinking is backwards. I should INCREASE the "Injector Bias (added)" because of the increased FP. The problem is the injector's spray pattern does not have a nice defined "cone". Instead it is a bunch of larger "streams" in a kind of cone pattern. If that makes sense. Would this be cause by a slow to open injector?
Thanks in advance to anyone with ideas about this.
Maybe my re-man injectors (sold to me as brand new) are just bad

 

When changing injector size or fuel pressure you should change injector bias (if the resulting flow is changed). You should only use big block bias if they use 80pph injectors at 18psi, else you should calculate the correct value.