zr1 (the supercharged one) has a dual fuel pressure operation. this is apparently what they were getting ready for with an absolute pressure scale. way cool!
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zr1 (the supercharged one) has a dual fuel pressure operation. this is apparently what they were getting ready for with an absolute pressure scale. way cool!
RHS,
Thats what I figured it was leading too. The FORDS use this kind of format but they have a pressure sensor to provide input to the PCM.
I guess for a NA situation, only half the table is utilized. Now the wonder is if we do a boosted application how can we get this info back into the PCM without a input sensor.
I also thought the LS9 was going to run with a E67 PCM....
Justin, have you logged that pid?
HT
Maybe this table is not being used right now?
So 400 KPA is know equivalent to 0 KPA and 500 is equal to 100 KPA or WOT....
I see that parameter where its either MAP or vacuum......maybe that allows the other half of the table to be active.
Howard,
Good question to start this thread. Now we are all confused. :doh2:
MANVAC 0 kPa is 100% WOT. That's why the IFR values are lower at 0.
Joe
LOL!! I guess sitting on couch late at night after tuning you can't help but ponder in some of these evolutionary changes!
Seems like its like gauge pressure vs. absolute pressure.
The table goes from 128 to 640 KPA. This is obviously a value based off a absolute value. Question is how is this relative to gauge KPA that we see with the MAP sensor?
http://www.radyoruzgar.com/video.asp...orvette&page=1
ZR1 "flat out" video!
Hi Howard,
If that is absolute fuel rail pressure, then those numbers would be reversed like Joe said...
500 kPa would be at MAP = 0 kPa (full vacuum, MANVAC = 100 kPa)
400 kPa would be at MAP = 100 kPa (WOT, MANVAC = 0 kPa)
pressure difference across injector
= absolute rail pressure - MAP
= 500 kPa - 0 kPa = 500 kPa (the first case above)
= 500 kPa - 100 kPa = 400 kPa (the second case above)
i.e. the pressure regulator is set to 500 kPa absolute pressure which is simply 400 kPa gauge pressure.
(rememeber: 400 kPa is 58 psi)
i'm not sure what is there to be confused about: with 400kpa being NA WOT, anything bigger than 400 is vacuum, and anything smaller than 400 is boost.
IFR is a function of MANVAC (or MAP and BARO, whichever you prefer), that's why it makes sense that the IFR table uses absolute pressure as the indepdent variable.
The next question is, where is 400kPa (gauge, 500kPa absolute) defined as the system's fuel pressure?
Edit: It's not. This things apparently have a fuel rail pressure sensor from the factory that explicitly tells the PCM what pressure it's getting.