[lowrydr310]

I recently flashed MHD Stage 1 91ACN a few days ago and got a chance to do some data logging:

https://datazap.me/u/lowrydr310/mhdv10s191acn-dtcdscoff

Tune is for 91 but this was done on 94 octane (7 gallons of 91 and 3 gallons of 101) to rule out fuel quality issues.

I don't understand the timing corrections. Before the start of the run there were timing corrections across all cylinders, then during the run there were no corrections. It looked perfect until I shifted into 4th then there were several corrections across multiple cylinders. I saw this same behavior on the stock tune. Anything to be concerned with? What causes this?

Also, my fuel trims are off quite a bit between banks. Bank 1 short term and long term are much more negative; does that mean the DME is compensating for a rich condition? Bad upstream O2 sensor perhaps? Bad injectors spraying too much fuel? My Bank 1 injectors are index 1 original from 2007, but no signs of leaks. No misfires, plugs aren't wet or black, car starts up perfectly overnight with no smoke. Just these negative trims.

Car has 160K miles, it was all stock when I bought it earlier this year. I replaced plugs and coils and got the intake valves walnut blasted right away, replaced PCV valve with the metal one from RB along with a new PCV flapper hose, and brand new boost solenoids. Also installed a new LPFP, regulator, and low side fuel pressure sensor.

I think I need an upgraded intercooler. IATs went from 100 to 153 and ambient temps weren't even that hot.

[Pyrat_1M]

If you look at your throttle position trace, you'll see where your timing corrections are coming from.... turn TC off when logging.

[lowrydr310]

Originally Posted by Pyrat_1M

If you look at your throttle position trace, you'll see where your timing corrections are coming from.... turn TC off when logging.

It was off completely for this log. I'm not seeing the correlation between throttle position and traction related timing cuts in this graph.

I actually had to repeat an earlier run immediately before the one posted above because I forgot to disable traction control. Here's the initial one with traction control left on:

https://datazap.me/u/lowrydr310/mhdv10s191acn-tract

[SlowE92]

Originally Posted by lowrydr310

I recently flashed MHD Stage 1 91ACN a few days ago and got a chance to do some data logging:

https://datazap.me/u/lowrydr310/mhdv10s191acn-dtcdscoff

Tune is for 91 but this was done on 94 octane (7 gallons of 91 and 3 gallons of 101) to rule out fuel quality issues.

I don't understand the timing corrections. Before the start of the run there were timing corrections across all cylinders, then during the run there were no corrections. It looked perfect until I shifted into 4th then there were several corrections across multiple cylinders. I saw this same behavior on the stock tune. Anything to be concerned with? What causes this?

Also, my fuel trims are off quite a bit between banks. Bank 1 short term and long term are much more negative; does that mean the DME is compensating for a rich condition? Bad upstream O2 sensor perhaps? Bad injectors spraying too much fuel? My Bank 1 injectors are index 1 original from 2007, but no signs of leaks. No misfires, plugs aren't wet or black, car starts up perfectly overnight with no smoke. Just these negative trims.

Car has 160K miles, it was all stock when I bought it earlier this year. I replaced plugs and coils and got the intake valves walnut blasted right away, replaced PCV valve with the metal one from RB along with a new PCV flapper hose, and brand new boost solenoids. Also installed a new LPFP, regulator, and low side fuel pressure sensor.

I think I need an upgraded intercooler. IATs went from 100 to 153 and ambient temps weren't even that hot.

Yeah your long term and short term dip, probably feeling oscillation due to throttle cut, its trying to balance out your AFR. If you've already replaced plugs and coils I'd check for leaky injectors, possibly 02 sensor because it stays on bank 1 for the most part.

[lowrydr310]

Originally Posted by SlowE92

Yeah your long term and short term dip, probably feeling oscillation due to throttle cut, its trying to balance out your AFR. If you've already replaced plugs and coils I'd check for leaky injectors, possibly 02 sensor because it stays on bank 1 for the most part.

There are two Index 12s and one index 9 on bank 2. I replaced the other index 9s because they were really noisy when cold. The front bank are original index 1. No obvious signs of leaks on any of the injectors though. Starts up fine. Plugs are dry and indicate clean burning.