E38 VVT Questions (L92) Late 2006 Build

[ringram]

Ok, Ive read a bit on the VVT functions, but have some questions.

First a couple of assumptions. Number 1 is that almost all the time (at sea level or there abouts) I will be running the high barro VVT table.

So my questions are.

1. Does VVT Timing adjustment B5154 apply across all 3 barro tables and is it scaled in any way based on VVT retard angle etc?

2. At part throttle around 2000 RPM give or take I get what feels like a surging/pulsating feeling. I thought this might be spark issues, plugs or leads etc. But it seems limited to this range. Which is pretty much the RPM where you get Max VVT timing and cam adjustments. So Im wondering if I am feeling the transitions across cells for timing and/or cam advance? Has anyone experienced this?

Next step, which probably should have been first step is to log everything :) And come back to add to this thread...

[ringram]

2009 Tables are quite different. A slightly more gradual ramp in cam phasing as load increases. And different B5154 values... Does anyone have an OEM 2013 L92 ctz?

[ringram]

Ok looks like timing does apply, ... and its too much. Logging spark adders and will attack B5154

As a general comment the 07 OEM tune sucks, the cam phaser goes from zero to like 25 in one cell or close to. So you feel this as a pulsing/surging as you drive along. Made me think something was wrong. But I blended it better modelled after the 10 tune and its way better.

Now to attack all the KR from the adder. It doesnt even match the cells the phaser is active in.

[pir4te]

FWIW I found with updated Torque Model values it is not so much the stock commanded cam position that is SNAFU, but amount of movement in proportion to VVT spark that makes things wobbly.
Start with phaser consideration turned off and get high octane right and safe as normal. I simply use the latest applicable stock VVT OS values as a base tune which includes swapping every value in the torque model.
Then turn on VVT and trial movement and spark at (max ground cam advance / mean retard near 5500 RPM WOT per stock tune). Apply that factor to stock VVT tune in seperate instance of EFI. Copy movement over to each High / Med / Low / AFM table.
That gives max movement authority with conservative VVT spark. Increment VVT spark 5% in the stock instance and copy over until confidently happy, closer to 100% stock spark.
I run 2016 Stingray HO / LO / AFM spark, Torque Model, all spark tables including 100% VVT spark with 55% movement. Tune built on ethanol to allow safe margin but Stingray values work great on pump gas as well. Trans will need a tweak to suit.
Cam is mid 20s with 6 degree advance, 13.5:1 CR, idles 550, VVT kicks in with PE as commanded like a 6.x litre ricer rush, yet during Atkinson phase with AFM active gets over 30 MPG.