Self Learning Ignition

[Mildman]

Hey all,

First major question to this forum....

I have a BF XR6T, stock.

I've been using 91RON since I bought the car in Nov last year.

I've now switched over to 95RON.

I was wondering how long it would take the engine management computer to work this out, and advance the timing accordingly, as I want to gain the benefits of the higher octane fuel.

Reason for using 91RON, fuel card wouldn't let me use Premium....and now it does!

Appreciate your input

Mildman

BF XR6T

Stock

1/4 mile: ???

Edited 05/03/06 09:09 AM by Mildman

[Mildman]

Hey all,

I asked this question to a friend of mine who creates OE calibrations for at least one OE customer.

He tells me that it takes about half a tank for the Visteon EMS system...and I quote.

"The engine will always attempt to run on knock limit for best performance unless other conditions tell otherwise such as knock sensors. The driving dynamics will speed up the adaptions, as greater spread of the map is used and therefore should increase the adaption time faster. Less than half a tank will do it"

He goes on to say that 98RON and 100RON are not worth putting in the tank, and to stick with a servo with high fuel turnover for my 95RON.

The higher the RON, the more volatiles, the quicker it 'goes off'.

This info answered my question, and hopefully in posting the answer it saves a few more of us asking the question.

Edited 05/03/06 10:25 PM by Mildman

[RAPHOON]

  Mildman said:

Hey all,

He goes on to say that 98RON and 100RON are not worth putting in the tank, and to stick with a servo with high fuel turnover for my 95RON.

Thanks for the info Mildman.

You should ask you contact to drive in a modified car and still stick to this statement........

[Paradoxx]

Obviously modified will be different, such as edit... it is tuned to run on the higher octane fuel and using lower will mean it is going to retard timing more often due to knocking.

I would think it takes longer for the stock tune to adapt to fuel though... when you get a re-flash from the factory it will take about 1000km to get to full potential, I have experienced this several times (and even with the EDIT you can notice the difference after 1000km).

[faygun]

  XXXR6T said:

Obviously modified will be different, such as edit... it is tuned to run on the higher octane fuel  and using lower will mean it is going to retard timing more often due to knocking.

I would think it takes longer for the stock tune to adapt to fuel though... when you get a re-flash from the factory it will take about 1000km to get to full potential, I have experienced this several times (and even with the EDIT you can notice the difference after 1000km).

<{POST_SNAPBACK}>

not trying to hijack the thread or anything but I didnt think Edit could detect knocking. I thought it was tuned for whatever you fuel you had at the time of the tuning.

[Chooka]

  faygun said:

  XXXR6T said:

Obviously modified will be different, such as edit... it is tuned to run on the higher octane fuel  and using lower will mean it is going to retard timing more often due to knocking.

I would think it takes longer for the stock tune to adapt to fuel though... when you get a re-flash from the factory it will take about 1000km to get to full potential, I have experienced this several times (and even with the EDIT you can notice the difference after 1000km).

not trying to hijack the thread or anything but I didnt think Edit could detect knocking. I thought it was tuned for whatever you fuel you had at the time of the tuning.

It still detects Knocking and from what I beleive is always enabled

Chooka

[Paradoxx]

Sure does, unless you disable it

You would be mad not to run it

[Mildman]

  RAPHOON said:

Thanks for the info Mildman.

You should ask you contact to drive in a modified car and still stick to this statement........

<{POST_SNAPBACK}>

I'll ask, but I belive the reason is that the Visteon computer has two advance ranges in it one suited to 91RON and a high end advance curve suited to 95RON.

The stock computer wont continue to advance past these maximum values.

I'll see if I can confirm this too.

[tab]

  Mildman said:

  RAPHOON said:

Thanks for the info Mildman.

You should ask you contact to drive in a modified car and still stick to this statement........

<{POST_SNAPBACK}>

I'll ask, but I belive the reason is that the Visteon computer has two advance ranges in it one suited to 91RON and a high end advance curve suited to 95RON.

The stock computer wont continue to advance past these maximum values.

I'll see if I can confirm this too.

<{POST_SNAPBACK}>

Don't mind Raphy, he's comparing an orange with an apple!

After my fully calibrated testing (gut feel; that's a lot of feeling as those that know me will testify) there is f*ck all difference between 95 & 98 - definately not enough to justify the extra $'s in any case.

[Adam]

  faygun said:

not trying to hijack the thread or anything but I didnt think Edit could detect knocking. I thought it was tuned for whatever you fuel you had at the time of the tuning.

<{POST_SNAPBACK}>

CAPA Edit cannot detect engine knock...

The CAPA Edit program is merely a tool used to change the values in the factory PCM programing.

So it's actually the factory PCM with the help of the knock sensors that detect engine knock.

The CAPA Edit software just gives the tuner the ability to adjust how aggressive the knock function remove timing if a knock is detected or the knock detection can be turned off completely.