What to Tune First

[SSpdDmon]

So the VE still kicks in during throttle transitions, which means you'll have to filter these out completely.

Regardless of whether or not the first part of this statement is accurate, I consider tuning out transitional data in my logs a standard practice....based on the assumption that if you get things working right during the consistent scenarios (between MAF/VE/Injectors), the transitions should fall into place.

[TAQuickness]

Good stuff Jeff. I'll give this a shot with the new build.

[jfpilla]

So the VE still kicks in during throttle transitions, which means you'll have to filter these out completely.

I must be slow.
If it still kicks in what does setting B0120 to 100rpms do?

[VTC_WS6]

RPM Threshold for Airflow Calc {B0120}: Using your stock, screened MAF, set this threshold to 100rpm to enable a full, MAF-only tune. The purpose of this is to reverse engineer your IFR table based on how the injectors flow in YOUR car.

Now in the case you're using a set of large injectors right off the bat, I presume this will cause an issue if I were to just toss a fresh base map in there and begin with this approach (w/o regard to IFR), is this correct?

[dc_justin]

- Throttle Transitions: VE table, regardless of B0120.

So the VE still kicks in during throttle transitions, which means you'll have to filter these out completely.

From all of my testing, I would have to disagree and say that once B0120 condition is met, MAF is used exclusively airflow calculation, transient condition or not.

Justin

[joecar]

From all of my testing, I would have to disagree and say that once B0120 condition is met, MAF is used exclusively airflow calculation, transient condition or not.

Justin

Oh, it does...? Then I'm wrong, I stand corrected and I edited my post: showpost.php?p=68499&postcount=9

[jfpilla]

From all of my testing, I would have to disagree and say that once B0120 condition is met, MAF is used exclusively airflow calculation, transient condition or not.

Justin

Thanks Justin,
It would make no sense, otherwise. I'll run some longer scans and see what I can, anyway. I like this idea.
Joe

[joecar]

Thanks, I'm going to rerun some of my experiments (zero out VE table and B0120)... ...I'm now sure I goofed up along the way...

This means that an AutoMAF tune should be very easy...

- Throttle Transitions: VE table, regardless of B0120.

If engine speed is above this value, then the PCM will use the MAF sensor exclusively (if not disabled by DTCs) to calculate grams of air per cylinder.

This is the EFI descriptionof B0120. Is it wrong?

Regardless of whether or not the first part of this statement is accurate, I consider tuning out transitional data in my logs a standard practice....based on the assumption that if you get things working right during the consistent scenarios (between MAF/VE/Injectors), the transitions should fall into place.

So the VE still kicks in during throttle transitions, which means you'll have to filter these out completely.

I must be slow.
If it still kicks in what does setting B0120 to 100rpms do?

From all of my testing, I would have to disagree and say that once B0120 condition is met, MAF is used exclusively airflow calculation, transient condition or not.

Justin

Thanks Justin,
It would make no sense, otherwise. I'll run some longer scans and see what I can, anyway. I like this idea.
Joe

And my partial-point about transient filtering was not lost... ..I am having a day, arn't I... ...I'm always learning.

[jfpilla]

Thanks, I'm going to rerun some of my experiments (zero out VE table and B0120)... ...I'm now sure I goofed up along the way...

This means that an AutoMAF tune should be very easy...



And my partial-point about transient filtering was not lost... ...I am having a day, arn't I...

Joe,
Your contributions are appreciated. The icon is not too subtle, is it?
Joe

[SSpdDmon]

Now in the case you're using a set of large injectors right off the bat, I presume this will cause an issue if I were to just toss a fresh base map in there and begin with this approach (w/o regard to IFR), is this correct?

I haven't tried to do this with stock injectors. I don't know for sure how it would fair. If you do try it, proceed with caution and let us know what kind of results you get. To be safe, you could try reducing the stock IFR table some just incase...

Remember, this method is in recognition of the idea that something is being fudged. Whether it's the MAF or the IFR table, something isn't right. As a result, we're trying to deal with it the best we can. My goal here is to get some 'outside the box' thinking going - especially since the opening line of this thread is....

This is not the end-all-be-all bible to tuning. It's just 1 of 101 ways to tune that delivers consistant and repeatable results.