September 17, 2007

EEC Tuner tuning notes

Most of the information in this file is directed specifically at the A9L processor. However, the information is still applicable to the other processors in theory and description of operation.

This is a work in progress. Comments are welcomed and appreciated.



PIP
Think of this as a rev limiter using the following formula:
PIP = 6006250/maxRPM
maxRPM = 6006250/PIP
for example stock A9L
PIP = 961 maxRPM = 6006250/961
= 6250 rpms
Lower numbers give a higher rev limit.

The PIP is a sample rate frequency that limits the PCM program operating loop to a minimum rate. If the loop is sampled less then PIP times within one operating cycle (2 crankshaft revolutions), the PCM limits rpm.

With this logic, you should be able to set the pip to 1 and the car should run normally, but not limit RPM. I have tested this on an A9L processor.


WOT_VOLTAGE
The WOT_VOLTAGE defines the throttle position that WOT operating mode is entered. On A9L processors, the WOT_VOLTAGE is the measured TPS voltage minus the idle voltage. That makes the stock 2.71 volts really ~3.71 volts as read on the TPS signal line. TPS usually goes to 4.6V at full scale. So stock WOT operation is triggered at about 80% and up throttle. You can control when the WOT functions and scalars are used by adjusting this value.
The following tags are only active during WOT operating mode
WOT_SPARK_ADDEER
WOT_ADVANCE_VS_RPM
WOT_FUEL_MULTIPLIER_VS_RPM
WOT_ADVANCE_VS_ECT
WOT_ADVANCE_VS_ACT


CRANK_FUEL_PULSEWIDTH_MULTIPLIER_VS_TIME
( 8191.88, 1 ) ( 0, 1 ) ( 0, 1 )
( 0, 1 ) ( 0, 1 ) ( 0, 1 )

This function is used to modify the CRANK_FUEL_PULSEWIDTH_VS_ECT values. The x value is the time in seconds, the y is the multiplier. This allows across-the-ECT-range pulsewidth changes without having to enter new ECT-dependent pulsewidths.

This is useful for reducing the pulsewidth when using larger injectors. This dramatically improves engine starting, and the surge that comes right after starting with larger injectors. I suspect the surging is burning latent fuel from a wet manifold that was over-doused with fuel. Set the multiplier in proportion to the size of the new injector.

For example: If going from 19 to 36 lb/hr injectors. You might use the following function. 19/36 = c
CRANK_FUEL_PULSEWIDTH_MULTIPLIER_VS_TIME
( 8191.88, 0.53 ) ( 0, 0.53 ) ( 0, 1 )
( 0, 1 ) ( 0, 1 ) ( 0, 1 )


The smallest pulsewidth appears to be about 2ms. A lower multiplier will not lower the pulsewidth below 2ms. However, a zero multiplier produces a 0ms pulse.
Using the 0 multiplier you can introduce a period where the engine is cranking, but the fuel injectors are not introducing fuel -- just like WOT cranking without holding the throttle wide open. This can be useful for cars running very large injectors, such that a 2ms pulsewidth will still flood the engine on starting.

For example: I use this on my car with 50 lb/hr fuel injectors. Without this setting, it will not start when its warm -- I will have to start it at WOT to clear the flooding
CRANK_FUEL_PULSEWIDTH_MULTIPLIER_VS_TIME
( 8191.88, 0 ) ( 3, 0 ) ( 1.5, 0.35 )
( 1.5, 0 ) ( 0.75, 0 ) ( 0, 0.35 )

This function would gradually, over 3/4 of a second, reduce the injector pulsewidth from 0.35 full value to 0. Then from 3/4 of a second to 1.5 seconds, no fuel would be delivered. From 1.5 seconds to 3 seconds fuel delivery would decrease from 0.35 full value to no fuel. From 3 seconds to 8191.88 (infinity in relation to cranking), no fuel would be delivered. This would clear any flooding condition as I crank beyond 3 seconds.


CRANK_FUEL_PULSEWIDTH_VS_ECT
( 65534, 0.00199893 ) ( 180, 0.00199893 ) ( 150, 0.0023003 )
( 70, 0.00569924 ) ( 40, 0.010502 ) ( 20, 0.0141489 )
( 0, 0.0218891 ) ( -20, 0.0387617 ) ( -65536, 0.0387617 )
Format: (ECT in degrees F, injector pulsewidth in seconds). Notice how dramatic the pulsewidth changes as the ECT changes. For example, on the A9L series a 10.5 ms pulsewidth at 40F changes to a 2.3ms pulsewidth at 150F. This may be a critical adjustment for larger-then-stock injectors and easy starting.


CLOSED_THROTTLE_SPARK_ADDER, PART_THROTTLE_SPARK_ADDER, WOT_SPARK_ADDER -
GLOBAL_SPARK_ADDER
xxxSPARK_ADDERs can be positive to add timing, or negative to remove timing.


TIP_IN_RETARD A positive number pulls out that number of degrees right after a shift. A negative number here might, presumably, advance ignition after a shift. Probably a dangerous thing!


CHECKSUM_BASE_ADDRESS - This is the starting address used to calculate a checksum on the ROM. The checksum test processes blocks of code until it reaches a base address that is 0. Set this value to 0 to remove KOEO error code 15 (checksum test error). The ROM checksum is valid only on the stock calibration -- Once you change anything, the checksum is invalid and error code 15 is generated.

It is not known if the presence of error code 15 effects PCM operation -- such as not storing keep-alive memory.


OPEN_LOOP_IDLE_MULTIPLIER 1 #(ZA0 series)
This variable modifies the fuel mixture at idle when the vehicle is in OL mode
(during cold start). A lower value richens the mixture.
You might use this if you run a radical cam and the car won't idle smoothly until it gets warm

INTAKE_VOLUME 5.5 # Intake Manifold Volume
You should play with this a bit. It is a non-critical measurement. People tell me it has an effect on throttle response. The GT40 has a larger volume -- try a value of 6. I don't know what the units are.


MAF_VOLTAGE 4.78523 # Max MAF voltage
MAF_VOLTAGE defines the maximum usable voltage as sent from the Mass Airflow Sensor signal line. This parameter essentially caps the maximum measurable airflow. When airflow reaches a rate such that the signal voltage is higher then MAF_VOLTAGE, the PCM fixes the fuel delivery rate as though MAF_VOLTAGE air is flowing. Raising this value from 4.7853 to 5.00 can increase the potential airflow measurement by 40%!. This assumes that your Mass airflow meter reports accurately at these higher rates.


FUEL_TABLE_ECT_SCALING #
( 254, 9 ) ( 240, 9 ) ( -30, 0 )
( -256, 0 ) ( -256, 0 ) ( -256, 0 )
This function defines the ECT values for the columns of the following tables:
STARTUP_FUEL_TABLE
BASE_FUEL_TABLE


FUEL_TABLE_LOAD_SCALING
( 1.99997, 7 ) ( 0.899994, 7 ) ( 0.700012, 5 )
( 0.399994, 3 ) ( 0.149994, 1 ) ( 0.0750122, 0 )
( 0, 0 )
This function defines the load (volumetric efficiency) values for the rows
of the BASE_FUEL_TABLE.


EMISSION_TABLE_LOAD_SCALING #
( 1.99997, 7 ) ( 0.75, 7 ) ( 0.600006, 6 )
( 0.100006, 1 ) ( 0.0499878, 0

 

I can think of maybe... five people on this forum that have a clue as to what you just posted

 

[sm=dontgetit.gif]

 

i get some of it. i will understand more down the road, but i will use this info,thx

 

I was going to say something similar. I can think of like three people off the top of my head. Me, you, and VRIstang (jason.) I was going to change some of it and add clariication, but then i figured it wouldn' matter since 99% of the people cant even alter these things anyway.

 

Ok I am a NOOB to EEC tuning I just recently purchased a burn1 and f3 ect and this was pretty helpfull.

How about a run down on speed density EEC defintions. Now that is a challange.

 

I've never seen anything specific to the SD Ford systems...
Then again.... I never really looked for SD info.


This is areason why MAF > SD
The 'tuner' support is better developedwith MAF ecu's...

 

well now its 4 people who understand that post. After having the tweecer for about 7 months Im proud to say that I do understand this stuff....finally!

thats some great info. do you thing you can post that on the other EEC tuning fourms??

Eric

 

http://EECTuning.org



this is the official tweecer tuning support site for all of our ECM's, in fact, tweecer has grown to support a vast majority of ECM's.[>:]


Now that was back in 07, and still works for me, but I would investigate recent changes and dont EVER FORGET TO GET A TPS REPORT. This is the most common problem for experts and novinces.

In fact, once you get good with it, youll discover the power your Stang was meant to make[8D]


HCI, MAF, TB , CAI with a good tune has been known to add 20+rwhp, more on Boosted Apps