Thread: Could someone please explain...

Hi team,

I'm unsure about a few of the settings / tables actually do and their effect; please note that I HAVE read (though failed to understand) the "help" section of the NEMU program, what these particular things actually do.

And before someone says, please read and understand the help section and it's terms first, I am NOT a full time tuner, there are other things in life that I prefer to do, rather than reading something that I struggle with making any sense of, like improving my work output, and chasing Women around (though usually with about as much success).

So far I have simply used the SR20 (370VE) base, as I have an SR20 VE running 370cc injectors, and tried changing some of the factors.

ACCEL / DECEL tab, ACCEL PARAPMETERS, SYNC ACCEL; I assumed that the dMAP tick option is for when using a MAP sensor, as opposed to a MAF?
What effect does the dTPS Deadband and also dTPS decay settings have?
dTPS MAF LOAD FACTOR TABLE, what does this do? I.e. does MORE in each box increase the fuel delivered at those loads?

DECEL, DECEL PARAMETERS
What effect does the dTPS Deadband, dTPS decay, and dTPS MAX DURATION settings have?
Is more better, i.e is a higher number mean more deceleration = less fuel?

dTPS MAF LOAD FACTOR TABLE & dTPS RPM FACTOR TABLE; do higher numbers = more fuel removed?
dTPS MAX TPS RPM TABLE & dTPS MID TPS RPM TABLE? What do these do? Why MID?
These seem to have a HUUUUUUUUUUUUUUUUGE effect on driving, and cause bucking and instability if wrong; but are they too high or too low?
Does the MAX mean that it's limited to that figure, if so would that mean that 255 would be the ideal?

I really appreciate all and any help and assistance with this.

PLEASE NOTE THAT I REALLY ENJOY THE NEMU PRODUCT and the continued effort and assistance and the upgrades!

I will try to work on a better explanation of the decel and accel tables in the help. The dTPS trim you see is the TOTAL accel fuel due to change in throttle.

You have a base table, and then "factor" tables that will add to that table depending on certain conditions (load, RPM, TPS).

The base table is "dTPS BASE TIF ECT TABLE" and the factor tables are "dTPS TPS FACTOR TABLE", "dTPS RATE FACTOR TABLE", "dTPS RPM FACTOR TABLE".

So what happens here is you start with your base table value and then you will multiply that table by all of the factors from the rest of the tables.

So say you base table is 5.4 msec and the factor tables are all 100% .. then your dTPS fueling will be 5.4 msec.

If you base table is 5.4 msec and all of your tables are 100% except your "dTPS RPM FACTOR TABLE" is 50% .. then your dTPS fueling will be 2.7 msec.

I will write a much better explanation for the help section, but that is a brief overview.

OnTheChipmight be able to elaborate a bit more.[/QUOTE]

Hope that helps abit?

Hope that helps abit?[/QUOTE]

TBH, no.

Where does the 5.4ms come from?

Just as confused.

What about something like bigger numbers here means more fuel when at higher loads, larger numbers in this table mean more fuel, when pressing the accelerator faster, this table is the amount of time it takes to react from initial press of the accelerator; you know English?

i totally understand what your saying, i get very confused too.. i read an read an read an i always pull it up when im not sure about something.. but in the end of the day i generally just make minor adjustments an see how it reacts.. if it does what i wanted then i know im in the right area lol

The 5.4ms is a completely made up number that I was using as the "BASE" table accel value.

The final async fuel trim is calculated by MULTIPLYING the BASE IPW ECT TABLE by all of the factor tables

In the case of the Async trim those factor tables are.

• MAF LOAD FACTOR TABLE
• MAP LOAD FACTOR TABLE
• NORMAL dTPS FACTOR TABLE WHEN FUEL CUT NOT ACTIVE
• FUEL CUT dTPS FACTOR TABLE WHEN FUEL CUT IS ACTIVE
  

If you look at the base aysnc table below, you will see that the BASE table is in msec.

So, lets assume your engine coolant temperature is 176 (normal operating temperature) then go into the BASE IPW ECT TABLE and you will see that your "BASE" pulsewidth is 4 msec.



After we get the 4 msec from that table as our "BASE", we will then have to go into the "FACTOR" tables to apply a "TRIM" to the "BASE" under different load and throttle conditions.

So, lets assume your engine is running a MAF sensor, so in this case you would simply look at your current MAF value and look up the "FACTOR" in the MAF LOAD FACTOR TABLE. You will see that the "FACTOR" is a percentage, so the higher the percentage the higher your final outcome will be.

Lets assume your current MAF value is 56 and if you take that value and go into the MAF LOAD FACTOR table, you will see that the "FACTOR" is 30 or 30%.



The next table we have to use is the dTPS (delta throttle position) "FACTOR" tables. THIS is where it can trip you up as the dTPS factor is pulled from 1 of 2 tables depending on the FUEL CUT STATUS. If FUEL CUT IS NOT ACTIVE, then the "FACTOR" is taken from the "Normal dTPS FACTOR TABLE", if FUEL CUT IS ACTIVE then the "FACTOR" is taken from the "FUEL CUT dTPS FACTOR TABLE".

Now, the dTPS tables are simply the rate at which you are opening the throttle and hence the reason for the Accel or (Acceleration Trims) .. when you are accelerating you are using the throttle or opening the throttle. So to cover this, we have a dTPS table or dTPS "FACTOR" that trims the Async Accel trim depending on quickly you push the throttle down. If you look below the greatest rate of change is to the LEFT side of the table and if you notice the "FACTOR" is also higher when the throttle is opened quicker.



So, lets assume fuel cut is NOT active, meaning we will use the "Normal dTPS FACTOR TABLE", and that the rate the throttle is opening at a rate of (.196 % / msec). If we got into the "Normal dTPS FACTOR TABLE" we can then see that the "FACTOR" at this dTPS rate is 38%.


Now that we have our "BASE" value and both "FACTOR" values we can then do the simple multiplication of those values.

The final Async trim in this case would be 4.0 msec * 30%(load factor) * 38%(dTPS factor).

What you would put in your calculator would be 4.0 * .30 * .38 = .456 msec of Asyc fuel being delivered.

So as you can see the "FACTOR" values from the tables have greatly reduced our "BASE" value .. so with that being said you can see that the HIGHER the factor tables the HIGHER the final Asyc trim will be!

that makes some sense, i'll def read it a few times over tho!

Agreed.

Thank you for the clarification.

Very thorough, though above my head, still.