Regrounded My MAF Virtual Dyno Numbers
Ever since I went to a Z32 maf on my NA VE, going to be boosted soon, I added an extra wire to ground it at the intake manifold. Well I drove like that for a long while. Yesterday I decided to finally ground it to the intake manifold. Look at the difference!
Keep in mind these are just estimated numbers calculated from a log file. Both days had similar temperatures, ~50*F. Unfortunately I didn't test on the same stretch of road, but the terrain was about similar. My usual difference between runs/terrains is 5-10whp at most, 30whp is no fluke, definitely all gains!
Red line is yesterday's run with a bad ground. Blue line is today's run with a good ground.
The AFR's are different I know, but as soon as I re-grounded the MAF my idle went from 15 AFR to 19 AFR, thus I have to completely retune. It looks like it's reading about .20-30v lower now then it did before, thus my TP doesn't go as high as it used to.
Now keep in mind I'm running a P11 with a step down harness. P11's ground might not be as good as others. P11 FSM warns against using ECU grounds to test MAF voltages. With a different ECU and MAF, this could mean MAF ground is insufficient.
Keep in mind these are just estimated numbers calculated from a log file. Both days had similar temperatures, ~50*F. Unfortunately I didn't test on the same stretch of road, but the terrain was about similar. My usual difference between runs/terrains is 5-10whp at most, 30whp is no fluke, definitely all gains!
Red line is yesterday's run with a bad ground. Blue line is today's run with a good ground.
The AFR's are different I know, but as soon as I re-grounded the MAF my idle went from 15 AFR to 19 AFR, thus I have to completely retune. It looks like it's reading about .20-30v lower now then it did before, thus my TP doesn't go as high as it used to.
Now keep in mind I'm running a P11 with a step down harness. P11's ground might not be as good as others. P11 FSM warns against using ECU grounds to test MAF voltages. With a different ECU and MAF, this could mean MAF ground is insufficient.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in damage
to the ECM’s transistor. Use a ground other than ECM terminals, such as the ground.
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in damage
to the ECM’s transistor. Use a ground other than ECM terminals, such as the ground.