Knock / Ignition adaptations

[Tbonem3]

Is that the only time?

[sapote]

Very confusing - if I'm so rich that timing is being pulled.

If you're so rich, just go ahead and buy Tesla or Bitcoin stocks and don't worry about timing (the market).

[jet_dogg]

Is that the only time?

Referring to ecus in general.

I don't know all the parameters our dme considers when adjusting timing, but it's just trying to save the engine from harm by preventing pre-ignition detonations precursed by pinging picked up by the knock sensors.

[S54B32]

If -2 is not so good, can you comment on my -4 to -5 across all 6 cyl? Maint up to date, can think of much else to do. Stock car, stock tune, just headers cats in sect 1.

Are you sure your tune ist absolut stock, i assume you not talking about the car in your signature? Do you relocated your EGT sensor with new headers?

[sapote]

Is that the only time?

I believe the DME adjusted the timing according to the knock sensors only (it started with the mapped timing based on rpm, load, intake temp, etc.), so driving in hot weather can cause more pull back than in cooler ambient. Therefore comparing data with car in SoCal summer with someone in cooler climate doesn't make sense.

[Cubieman]

So if a stock tune allows the engine to have values of -4° (or higher) retarded and a CSL tune only allows -2° what could this mean for the engine?

What if the engine really needs to be retarded 4° but due to CSL engine management 2° is now the max. If it is the case that -2° is max retard on my version of CSL software and basically all of my cylinders are showing -2° I wonder how far the DME would retard timing running under stock DME software.

Although as I said before my values where much less when the vehicle was stock, I'll have to see if I tool a photo.
So we might think knock detection sensitivity could increase with CSL software or it simply expects better combustion from European fuel?

[Tbonem3]

Are you sure your tune ist absolut stock, i assume you not talking about the car in your signature? Do you relocated your EGT sensor with new headers?

Knowing the history of the previous owner so well (family member), I'm 99% sure the tune is stock. 2002 w/ 126k - not the car in my sig. Only mod is fabspeed headers, and the egt as well as precat o2s were migrated over. Hiflo cats in 2.5" sect 1 pipes.

Could catless headers be responsible? I assumed that you don't *need* a tune.

[S54B32]

I believe the DME adjusted the timing according to the knock sensors only (it started with the mapped timing based on rpm, load, intake temp, etc.), so driving in hot weather can cause more pull back than in cooler ambient. Therefore comparing data with car in SoCal summer with someone in cooler climate doesn't make sense.

Timing is influenced by different inputs (iat for example), but adaptions mostly on knock sensor as far as I know.

@cubieman: in CSL Software knock sensitivity is different from other software versions and can also be adjusted cyclinder selective. You also can set max retard to 6° for example and see how far it goes. You can send me your tune pulled with bmwflash or post the ignitions maps, that we can see how far your ignition is advanced.

@tbonem3: please compare your tune with tunerpro/hexedit with correct stock file to find it out. Or attach it here.


maybe also a Problem could be, if someone running CSL airbox but misaligned the IAT scaling for the sensor, it would also pull timing across all cyl.

[Tbonem3]

Thanks. Attach a partial here? I don't know how to compare anything or use tunerpro/hexedit. Most I know so far is to pull or flash with BMWflash and make edits with Marty's tool.

[S54B32]

Thanks. Attach a partial here? I don't know how to compare anything or use tunerpro/hexedit. Most I know so far is to pull or flash with BMWflash and make edits with Marty's tool.

Yes attach it here or send in pm if you don’t want it available for everyone.

[sapote]

Timing is influenced by different inputs (iat for example), but adaptions mostly on knock sensor as far as I know

It is still a mystery to me of how the DME uses the adaptation value, i.e. -3* CR for cylinder #1. Do you know if it use this 3* pull back only under heavy acceleration, or certain rpm range, and zero pull back during partial load and coasting, just an example?

[digger]

Any knock adaptation should be a 3D map. I gather this is just reporting the maximums.

[S54B32]

Any knock adaptation should be a 3D map. I gather this is just reporting the maximums.

Sadly this part of my functional description for mss54 is not available, I know of Bosch ME9.2.1’s do this, they store a adaption map with load/rpm cells. But I don’t know in mss54 it‘s handled this way. In WOT logs i see often exact this adaption factor applied. I assume it’s only a variable per cyl.

Next time when I do logging, I will take a look at various load conditions. Most time I concentrate on higher load areas only.