Boost reference FPR ?????
03-01-2007, 07:33 PM
#1
Boost reference FPR ????? When running a 1:1 boost referenced FPR...the pressure changes with vacuum.
is there anyway i can find how much the drop changes compared to vacuum besides hooking up a mityvac to the port on my reg.
im looking for what fuel pressures will be present for when i change my Injector Flow Rate tables to keep my tune aligned.
is there anyway i can find how much the drop changes compared to vacuum besides hooking up a mityvac to the port on my reg.
im looking for what fuel pressures will be present for when i change my Injector Flow Rate tables to keep my tune aligned.
03-01-2007, 08:53 PM
#2
Originally Posted by Ping King
When running a 1:1 boost referenced FPR...the pressure changes with vacuum.
is there anyway i can find how much the drop changes compared to vacuum besides hooking up a mityvac to the port on my reg.
im looking for what fuel pressures will be present for when i change my Injector Flow Rate tables to keep my tune aligned.
is there anyway i can find how much the drop changes compared to vacuum besides hooking up a mityvac to the port on my reg.
im looking for what fuel pressures will be present for when i change my Injector Flow Rate tables to keep my tune aligned.
I set my injector flow rate the same all the way across based on 58 psi.
03-01-2007, 09:05 PM
#4
i did it at one point just like you did...but when you think about it your tune will tossed around so much because your fuel pressure, and therefore your injector flow rates change. Im actually thinking of changing injector flow rates
03-01-2007, 09:42 PM
#5
no, by having a boost referenced regulator, and a single value injector flow rate, your tuning it correctly, not being tossed around due to pressure change.
The value that the pcm needs to know (or infer on a GM pcm, since there is no rail pressure sensor) is the "pressure drop across injectors" since this is what the injector flows.
If your at 51# rail, and -14" of vacuum (-7 psi) your still at 58# pressure delta.
If your in boost, 10#, with 68# of rail pressure, your still at 58# pressure delta.
Ryan
The value that the pcm needs to know (or infer on a GM pcm, since there is no rail pressure sensor) is the "pressure drop across injectors" since this is what the injector flows.
If your at 51# rail, and -14" of vacuum (-7 psi) your still at 58# pressure delta.
If your in boost, 10#, with 68# of rail pressure, your still at 58# pressure delta.
Ryan
03-01-2007, 11:42 PM
#6
Originally Posted by slow
no, by having a boost referenced regulator, and a single value injector flow rate, your tuning it correctly, not being tossed around due to pressure change.
The value that the pcm needs to know (or infer on a GM pcm, since there is no rail pressure sensor) is the "pressure drop across injectors" since this is what the injector flows.
If your at 51# rail, and -14" of vacuum (-7 psi) your still at 58# pressure delta.
If your in boost, 10#, with 68# of rail pressure, your still at 58# pressure delta.
Ryan
The value that the pcm needs to know (or infer on a GM pcm, since there is no rail pressure sensor) is the "pressure drop across injectors" since this is what the injector flows.
If your at 51# rail, and -14" of vacuum (-7 psi) your still at 58# pressure delta.
If your in boost, 10#, with 68# of rail pressure, your still at 58# pressure delta.
Ryan
you just clicked the lightbulb on. thanks!