Transfering Calibration from ABUT ['165] to OSE $12P Tables

[redcamaro]

I am attempting to extract the values from the original binary and put them into the OSE $12P tables. I think it will be a better value base to tune the 1987 V8 than the BLCF values.

My question is relating to the table rows and columns... For example, see the attached spreadsheet which has the Spark Advance vs RPM vs Load table from each binary. The ABUT has a finer calibration.

In terms of RPM ABUT steps up in smaller increments than the BLCF i.e. 400, 600, 800, 1000, 1200 and so on, as opposed to 400, 800, 1200 in BLCF. Can I insert the 600 and 1000, etc rows into the OSE $12P table (possibly sacrificing some of the higher RPM rows in BLCF)?

Similarly the ABUT columns are in relation to a MAF sensor, but I have replaced the MAF with a 1 bar MAP sensor... In the spreadsheet the ABUT Load columns are converted to percentages to map them against the BLCF MAP columns, and the ABUT has 12 columns whereas BLCF has only 11 columns.

Can I insert another column, into the OSE $12P table, and do the percentages Load/MAP conversion make sense?

[charlay86]

You can't really compare manifold pressure with cylinder air mass, their relationship is not linear.

[redcamaro]

How about if I get the MAP volts, and MAF voltages from MAF Tables #1-6 and compare those? Surely thats been done before?

Re: inserting rows and columns, I don't think that would work without modifying the software that uses the data I.e. $qwP, would that be correct?

[charlay86]

The MAF & MAP voltage correlation is even less linear; the problem is that MAP is (roughly) based on the throttle opening and the engine airflow, whereas in a MAF calibration the load index is the actual cylinder air mass.
RE: inserting columns - the issue with modifying the lookup table is more that the variables used internally by $12P for the lookup are a fixed resolution.

[charlay86]

Think about it like this, if you plotted mg/cylinder against rpm at WOT, you would see that the mg/cyl would increase until when your engine reaches peak torque and then it will start to drop;
if you did the same thing with MAP vs rpm, you would see the MAP value sit fairly constant (unless you have a restrictive inlet tract).

[redcamaro]

MAP is (roughly) based on the throttle opening and the engine airflow, whereas in a MAF calibration the load index is the actual cylinder air mass.

There must be some correlation, or a way of mapping between the sets of values. The actual cylinder gets its air mass only via the throttle body, which is what the MAP is measuring/estimating (roughly) the air flow of - right or wrong?

It seems that a MAF is more accurate (at a constant WOT). However it's gotta work somehow - they can both measure changes in air flow/demand, back to the task,.. to get to WOT it needs to be opened so the air can come in so during that process there would be a change in MAP output - wouldn't there be? I guess that increased air 'allowed in' would also be measured by a change in the MAF output.

Is there something I'm not getting here?

[charlay86]

The MAP sensor is used in conjunction with the MAT sensor to calculate the density of air in the manifold, which is then subject to calculations involving the speed, displacement and volumetric efficiency of the motor to get the mass of air in the cylinder.
To equate the 2 tables you would need to solve the speed density equation based on MAP/RPM for each column and then factor in VE to get the cylinder air mass; however this doesn't take into account the temperature portion of the equation, so you would only be solving it for a particular temperature...

[Holden202T]

when i wanted to convert a ecotec to map based computer what i did was use the injector line monitor wire to feed the map sensor signal into the pcm data stream, then i just logged actual spark advance against map and rpm t create a table for it.....

i don't know of any better way to do it .

[redcamaro]

I'm convinced that the MAF is a simpler, and more accurate measurement. It almost wants me to suggest an addition to OSE $12P - to have an option to use a MAF sensor. Maybe this can be done within the Flex Tables?

All I am trying to achieve is to take the MAF calibrations from the stock (ABUT) binary, and transpose them into the BLCF binary as (maybe approximate guesses) of MAP values, instead of MAF values. Is it really that complicated?

How would you go about building a spreadsheet to convert MAP tables to MAF tables using 'best possible' approximations. This is in order to take an old (or pre-existing) MAF based calibration and transpose it into a MAP based tune.

[Edit} have a look at this thread on thirdgen http://bit.ly/PNLmFp

[delcowizzid]

spark is easy goto 100 kpa colomn and add your typical chev WOT advance curve 800 rpm say 16-20 degrees ramp it up to 34-38 degrees all in by 3600-4000rpm in the 100kpa colomn and you will pretty much have a full msd dizzy mechanical advance curve and be close enough to make allright grunt off the bat at full throttle.goto the map colomn your engine cruises in say 40-50 kpa if theres a bit of cam and add 16 degrees timing to the 100kpa value at each rpm and enter that in the cruise map colomn this will give you the equivilent of the msd vacuam can at cruise on top of full throttle spark advance.taper the whole table from 50-100kp so it nicely slopes and that should be a good enough base spark table to fine tune from.

as for the ve table as long as you dont guess the injector constant its as easy as sit in the driveway for half an hour with your foot on the gas with bubble tracing on and and getting the bubble in as many cells as you can 1 by 1 and increasing or decreasing ve untill the engine sings youll hear it free up as you add fuel and youll need to keep lifting your foot further off the throttle to keep in the cell you are tuning.do this with closed loop disabled in the tune.full throttle set 100kpa colomn to all above 90% VE and lean out and richen where needed