MAF Calibration - Diff AFR at same MAF HZ at different speeds/loads
10-01-2007, 08:35 AM
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MAF Calibration - Diff AFR at same MAF HZ at different speeds/loads Posted this over at HP Tuners forum, but haven't heard back yet so I though I'd try here...
This has me beating my head against the wall. I have dialed in my VE table before starting calibrating my MAF BTW too.
I am running OLMAF and am now trying to dial in my MAF table and have run into a really frustrating issue. I have different AFR % error at the same MAF hz reading at different speeds (different load I would guess too).
Quick synopsis--at low speed when gently accelerating (1st, 2nd, and 3rd gear) staying in the same range of cells (approx 4250-4750 hz) and trying to keep throttle pretty constant I am rich (~11.5 - 12.8 AFR). I am not going into PE mode either according to my logged commanded AFR. When cruising down the road in 4th, 5th, and 6th gear, I'm a tad bit on the lean side in those same cells (15-15.2 AFR) though. It actually seems to get a little leaner each gear higher or while going faster. Needless to say this really throws off my average WB AFR % error and makes it impossible to tune.
This brings me back to a similiar issue I had which was running really rich on warmup. I found out why I was running WAY rich (10-11 AFR) while warming up idling--it was going into higher HZ MAF cells than the normal idle cell when warming up (around the 3750hz cell upon first cranking going down to 3125 when warm. I assume this is due to settings in the RAF table). Naturally I leaned those cells out in the MAF calibration and it now runs as it should warming up. The problem is though, if it's on for idle and warming up, when I hit those cells while driving, it's WAY lean (like 17-19 AFR). So I can either barely run when warming up, or barely run when driving around in those cells. WTF!?
I'm not really sure where to go from here. I know other people say they run OLMAF all the time with no problems, so I would think it should be able to be done ok, but I don't see how!? The only thing I can think of is that maybe it has to do with my MAF placement. I swapped a LS6 into a FD Rx7 and built my own CAI that places the K&N filter behind the driver side brake duct. The MAF is at the very end of the CAI tube and the air filter is attached directly onto the end of the MAF sensor. I figured I might have some turbulance with it mounted there, so I did leave the screen in the MAF sensor. Maybe my MAF is bad? Maybe I shouldn't have my air filter mounted on the end of the MAF?
I have attached my most recent tune and log file. Any help would be MUCH appreciated!!!!!
This has me beating my head against the wall. I have dialed in my VE table before starting calibrating my MAF BTW too.
I am running OLMAF and am now trying to dial in my MAF table and have run into a really frustrating issue. I have different AFR % error at the same MAF hz reading at different speeds (different load I would guess too).
Quick synopsis--at low speed when gently accelerating (1st, 2nd, and 3rd gear) staying in the same range of cells (approx 4250-4750 hz) and trying to keep throttle pretty constant I am rich (~11.5 - 12.8 AFR). I am not going into PE mode either according to my logged commanded AFR. When cruising down the road in 4th, 5th, and 6th gear, I'm a tad bit on the lean side in those same cells (15-15.2 AFR) though. It actually seems to get a little leaner each gear higher or while going faster. Needless to say this really throws off my average WB AFR % error and makes it impossible to tune.
This brings me back to a similiar issue I had which was running really rich on warmup. I found out why I was running WAY rich (10-11 AFR) while warming up idling--it was going into higher HZ MAF cells than the normal idle cell when warming up (around the 3750hz cell upon first cranking going down to 3125 when warm. I assume this is due to settings in the RAF table). Naturally I leaned those cells out in the MAF calibration and it now runs as it should warming up. The problem is though, if it's on for idle and warming up, when I hit those cells while driving, it's WAY lean (like 17-19 AFR). So I can either barely run when warming up, or barely run when driving around in those cells. WTF!?
I'm not really sure where to go from here. I know other people say they run OLMAF all the time with no problems, so I would think it should be able to be done ok, but I don't see how!? The only thing I can think of is that maybe it has to do with my MAF placement. I swapped a LS6 into a FD Rx7 and built my own CAI that places the K&N filter behind the driver side brake duct. The MAF is at the very end of the CAI tube and the air filter is attached directly onto the end of the MAF sensor. I figured I might have some turbulance with it mounted there, so I did leave the screen in the MAF sensor. Maybe my MAF is bad? Maybe I shouldn't have my air filter mounted on the end of the MAF?
I have attached my most recent tune and log file. Any help would be MUCH appreciated!!!!!
