auzoom

No one?

auzoom

bueller?....bueller?.....

Brettus

iTrader: (2)

Interesting . Should we be setting the entire IAT and Baro compensation tables to 1 to prevent this happening ?

lastphaseofthis

no, i would think that would throw things more off, as they are there for a reason. maybe mot the baro so much, but i would prefer to have to baro setup as a MAP. and hope that would impact the calc load, as you could index it to boost, ie. 100=0psi 150=15 psi 200=30 psi. if you're going to run high boost, or 0/7/15 if you're running low. but i'm pretty sure the cobb would need more software changes to make it effect it the way we all would like. or does it support this now?

TeamRX8

iTrader: (25)

you should have taken MM seminar however, looking back at my notes I only changed the IAT load map at one particular point per my previous mention of it

wcs

iTrader: (2)

My baro and IAT tables are flat at 1 and it's the way I like it.

I don't want anything removing fuel ...
What if the Baro sensor fails and starts providing a bad signal .... and thinks I'm on Mnt Everest or something.

My point .. I've had no issues tuning with these tables flattened

edit:
I've removed any area in these tables that have leaning effect on the end AFR ... if the BARO table has a .86 value ... it was flattened to 1
Values that increased the amount of fuel have been untouched ... for now

TeamRX8

iTrader: (25)

well your MAF can fail too, but air mass is air mass ... unless you are Brettus j/k

wcs

iTrader: (2)

^^^ Agreed Team .. and probably a bad example on my part.

Shouldn't the Maf have accounted for your cold front in term of air mass and air density?

Are you thinking you have a bad Maf and its not the tuning?

edit:
Still having those tables flat ... eliminates a lot of variables that really don't matter when you are FI

wcs

iTrader: (2)

Hey Team .. I know how much you love to blindly replace parts!

I think you should start with your coils
Replace the Cat
Then the TB

Report back


lolz

TeamRX8

iTrader: (25)

no, I was just poking at Brettus in good fun

my MAF is perfectly happy with a good atmospheric blow job ...

Brettus

iTrader: (2)

Did you set it at 1 for LOW temp as well as high temp ?

Because the low temp side increases the calc. load max. on the stock map . And you said it went lean in low temp condition right ?

Brettus

iTrader: (2)

yeah cuz if you are me you actually make power

TeamRX8

iTrader: (25)

Just want to clarify that they are load modifiers so they affect a number of engine control parameters, not just AFR

wcs

iTrader: (2)

@Team
So what's your strategy?

I'm assuming you still think its your tune not a mechanical issue?

Are you addressing the fuel tables then?

MazdaManiac

iTrader: (3)

Exactly.

You need the IAT modifier for the engine to operate correctly, especially in open-loop.

olddragger

iTrader: (3)

do most FI tunes have the baro flat at 1?

lastphaseofthis

if someone doesn't change elevation often, then i don't see this being a problem, until someone does take it up in the mountains without reflashing the baro table, and blows the engine from running lean, so why would you flash something, thats going to have to come back and get reflashed and fixed later on.. do it right the first time, IMO.

wcs

iTrader: (2)

So FWIW, here is a screen shot of my IAT and the Stock IAT

Now given that my setup is a draw thru and I don't have a Post Turbo IAT and:
- I live in a relatively cool climate
- I'm not tracking the car

I thought this was my best setup for the current environment

And given that I've never seen intake temperatures more that 20c degrees more than ambient (typically its about 10c more) that puts me around the 40c mark even in the dead of summer (104f is 40c)

I guess my understanding of how the Maf works is wrong.
The stock IAT table wants to take 10% off the load at 140f to compensate for the IAT.
Should not the Maf be able to measure the reduced air density as a reflection of a lower g/s?
edit:
I'm guessing it's compensating for the Maf?? Obviously it's reducing load based on IAT. Why else would you want to reduced the calculated load, to pull timing, AFR, or Fuel VE, all of the above.

I should take the time and go through the process of guesstimating my IAT Post turbo and Intercooler based on the Pre turbo IAT value.
Doing so would help keep you in the measurable universe as defined by our Calc Max Load table

My current setup
Attachment 178145

Stock values
Attachment 178146

wcs

iTrader: (2)

As far as the Baro goes,
I'm not sure how this applies if you are FI

doesn't the forced induction part cancel out the reduced atmospheric pressure?

MazdaManiac

iTrader: (3)

I do not.

Just a weather change can be up to 2 PSI difference in BARO.
I can have more than 1 PSI of BARO change within 40 miles of my house.

You begin your tune with them flat. Then you integrate the table to adjust for reality.

Kane

iTrader: (1)

No, remember the fixed volume, variable mass thing we talked about?

The compensation tables are used to calculate the mass of a fixed volume, and that is affected by the General Gas Law, actually in this case Boyles / Charles's Law since volume is fixed. So if the volume can't change, then the effect of temperature and pressure would be on the mass side of the house.



To elaborate: There are 4 variables in this picture - when you determine three of them, then you can solve for the fourth.... engine physics 101.

MazdaManiac

iTrader: (3)

That is negated by the use of a mass airflow sensor.

The BARO and IAT inputs are, essentially, error correction.

wcs

iTrader: (2)

I clearly need to cut down on my drinking

Brettus

iTrader: (2)

Exactly .

But are they really error correction or are they Mazda's attempt to create a more stable combustion for an NA engine when these variables come into play ?

If so the question for FI people becomes... what do we want to happen in an FI engine and what do we have to do to achieve it ?

MazdaManiac

iTrader: (3)

Semantics?

We want these functions to operate as they are designed.

Testing.

I spent many, many hours driving to locations that were below sea level and up to 12,000 feet above sea level and making comparisons and datalogs.

I also examined ranges of weather conditions from 27in/Hg to almost 33in/Hg with relative humidity from 2% to 100%.

It took almost a year of experimentation to come up with the correction values that work under all conditions for all of my FI calibrations.