injector flow rate b4001

[minytrker]

What does lowering that whole table do? I had a tune done last year and the guy lowered the whole table by about 2.

[fyi]

Makes the entire fuel curve richer- globally.


-john

[joecar]

B4001 (IFR table) tells the PCM what the injector flowrate is as a function of vacuum.

Lowering this table tells the PCM that the injector flowrate is less,
so the PCM will keep the injectors open for longer to get the fuel mass that it wants
(based on the cylinder airmass and the AFR that it wants to command).

If you're using closed loop, then lowering the IFR table will cause the LTFT's to trend negative
(i.e. subtracts fuel because it's detecting too rich).

There is a spreadsheet for calculating the IFR table:
http://www.allmod.net/hpt/injectors.xls

[minytrker]

Makes the entire fuel curve richer- globally.


-john

Wonder why he did that? My car was running rich, guess since he didnt have a wideband.

[Redline Motorsports]

What should we be using for the current fuel pressure values?? I know the LS1's are between 58-60. Should it be split in the middle or is it not that critical at that point?

[eboggs_jkvl]

Since I used the EFILive injector spreadsheet, I loaded 43.5 at 58psi and 60# injectors. Since my table used 58, I set 58 on the fuel pressure regulator. I doubt it critical but it was one of my parameters for setting the 4001 table for the new injectors so I maintain that as my starting fuel pressure.

Elmer