Using ignition trim for cylinder knock on boost & WOT AFR's
Posted: Mon Jun 03, 2013 10:03 am
I have an issue where there are knocks detected on cylinder 1 and sometimes on cylinder 3. I am new to tuning but understand it pretty well as I have background in automotive fuel management diagnostics and repair so am not oblivious to most things on FlashPro. I read the help files on many of the problems Ive ran into thus far and have managed to solve them but this issue I wanted to ensure I understood before modifying any tables.
Basically, if my datalog reads that ONLY cylinders 1 and 3 knocked, I should trim -1.0 (retard) off each cylinder until I no longer see any knocks recorded in the datalog right? Also, I can add +1.0 (advance) any other cylinders (2,4,5 and 6) and continue to advance until a cylinder knocks...at which point I back off (retard) 1 degree correct?
If the methods above are true, can the same be done for the low and high ignition tables? Would it benefit me to (starting at far left column) slowly advance the ignition one degree at a time until knock or power loss is detected and then back off a degree on that column? I could maybe even do this first and THEN use ignition trim to fine tune the table.
Or if anyone else has any better solutions/ideas on knock control, Id be happy to consider any logical approach.
And also one other question, Ive noticed that my AF ratio in datalog doesnt meet my table value for WOT fuel values. Datalog shows that if I have my AFR set at 11.50 at a specific RPM and MAP value, the actual AFR may be 13.30 and slowly drop over 2-5 seconds while sometimes spiking again between under WOT. What causes this sort of air/fuel inconsistency during WOT pulls...ignition maps?
Thanks in advance for all the help.
Basically, if my datalog reads that ONLY cylinders 1 and 3 knocked, I should trim -1.0 (retard) off each cylinder until I no longer see any knocks recorded in the datalog right? Also, I can add +1.0 (advance) any other cylinders (2,4,5 and 6) and continue to advance until a cylinder knocks...at which point I back off (retard) 1 degree correct?
If the methods above are true, can the same be done for the low and high ignition tables? Would it benefit me to (starting at far left column) slowly advance the ignition one degree at a time until knock or power loss is detected and then back off a degree on that column? I could maybe even do this first and THEN use ignition trim to fine tune the table.
Or if anyone else has any better solutions/ideas on knock control, Id be happy to consider any logical approach.
And also one other question, Ive noticed that my AF ratio in datalog doesnt meet my table value for WOT fuel values. Datalog shows that if I have my AFR set at 11.50 at a specific RPM and MAP value, the actual AFR may be 13.30 and slowly drop over 2-5 seconds while sometimes spiking again between under WOT. What causes this sort of air/fuel inconsistency during WOT pulls...ignition maps?
Thanks in advance for all the help.