Mini Tech Tips: Lean or Rich? CHIPS and EEC Replacements / EEC - Tuner FAQ
written by: GTRaptor
This is our first attempt to create a comprehensible FAQ about the EEC-TUNER, its not ordered right now in any special way but will eventually be and would cover most aspects from installation to tunning.
ELECTRIC FAN
SPEED and RPM LIMITERS
EMISSIONS ITEMS
AOD-E TRANSMISSION
FUEL AND AIR
ELECTRIC FAN
For the SN95s, the electric fan is toggled on and off in relation to the engine coolant temperature (ECT). Both high and low speeds are set top operate within ranges. The numbers below I am using in conjunction with a 180* thermostat.
ECT_HS_FAN_ON 198 # ECT to turn on HS cooling Fan ECT_HS_FAN_OFF 190 # ECT to turn off HS cooling Fan ECT_LS_FAN_OFF 182 # ECT to turn off LS cooling Fan ECT_LS_FAN_ON 188 # ECT to turn on LS cooling Fan
Here is how it will work: At 188* the fan will come on at low speed. If this is not sufficient, then the high speed will kick in at 198*. Once the high speed fan cools the solution to 190*, it will stop. Usually the coolant will continue to cool to 188* after the high speed stops and the fan will operate at low speed again. When the coolant reaches 182*, the fan will stop altogether. Note how the high and low speed ranges do not overlap.
SPEED and RPM LIMITERS
Speed limiters are the bane of Mustang owners, and are easily disabled. Enter a speed value that you do not intend to exceed. The speeds below are from a stock U4P0 processor.
Rpm limiters are also simply reprogrammed. The values below are standard for the J4J1 processor. I cut & pasted them into my U4P0 which has values much lower. Ford placed these variables to prevent the EEC from over-revving the engine, I would be respectful of them and use real world values.
EMISSIONS ITEMS
Emissions is most often either enabled or disabled by tuners. Here we have the typical race setup with both thermactor and EGR disabled.
AOD-E TRANSMISSION
The AOD-E is a rich arena for EEC tuning. Rather than give a primer on how automatic over-drive transmissions work, I will share my experiences tuning it with EEC Tuner. The scalars for the AOD-E programming are straight forward, and their names are as well. Once the rev-limiters have been raised, lifting the shiftpoints is nearly as easy. I say nearly because what you see is not always what you get. WOT shifting for me negates the need for the 3-4 shift. I have been warned by Greg at Baumann Engineering to turn O/D off when racing, he also warned against modifying the transmission pressure levels. Either of these can easily be damaged. Let's face it, the AOD-E was born with the need for upgrading, but that's another story. The WOT shiftpoint scalars are the rpm value where you want shifts to take place. I have found the 1-2 shift at WOT pays more attention to the function for upshift speed. The 2-3 shiftpoint is just about right on the money with this scalar's value. I would imagine the 3-4 shift is as easy, but I have not tested that attentively yet.
WOT_1_2_SHIFTPOINT 4400 # WOT 1-2 shift point
WOT_2_3_SHIFTPOINT 4900 # WOT 2-3 shift point
WOT_3_4_SHIFTPOINT 5000 # WOT 3-4 shift point
The upshift and downshift functions are value pairs (x, y), where x = TP voltage, and y = the vehicle speed at which you desire to shift. This is where the 1-2 shift is able to be tuned.
I just got back from test driving after having modified the WOT (first 2) UPSHIFT_SPEED_VS_TP_1_2 value pairs from 50 mph to 40 mph. My heads pull much harder at top-end than the stock heads, so I get to the top of first gear at a much more quickly. I want to target 5200 for my first shift, and have it now.
Another experiment I just logged with the upshift speed for 1-2 shift was the removal of the torque convertor's lockup in second gear. Yes, this is electronically controlled. I simply input a mph that I will not reach and as as result the shift from 1-2 just slides across, no jerky bang. This is not fuel efficient, but it yeilds quite a nice effect. Slide into gear. I think that, tuning for the drag strip, the 1-2 shift and lockup sufficient for now.
Transmission fluid pressure. Yet to be documented:
DYNAMIC_1_2_TV_PRESSURE_VS_TP # Dynamic TV pressure vs. TP
DYNAMIC_2_3_TV_PRESSURE_VS_TP
DYNAMIC_3_2_TV_PRESSURE_VS_TP
DYNAMIC_2_1_TV_PRESSURE_VS_TP
FUEL AND AIR
Air/Fuel programming is a great opportunity for exploiting the EEC to its full extent. There are many more places in the EEC memory that affect air/fuel ratios, but we will focus on those which have proven to be most effective for WOT performance and idle quality.
You can run any injector with a mass air meter that has stock calibration. I recently replaced my stock 19lb injectors with 24lb injectors, I cut & pasted the Cobra's injector values from the J4J1 processor into my U4P0.
Simple -- type the pound of injector you use and you are done.
Fuel manipulation is where those with forced induction will focus. No need for FMUs when this is properly done.
Running N/A myself, I have used the following functions to enrich my fuel at WOT. Look at the WOT_FUEL_MULTIPLIER function. Rpm values are associated with fuel leaning values. The U4P0 processor has only the max rpm value set, and all of the fuel leaning values are 1. I borrowed the function value pairs from the A9L processor to use, which has fuel enriching in place, and copied it into my U4P0.
You must understand that for a given (x,y), x = rpm, and y = fuel leaning multiplier. The 'y' value is a fuel leaning multiplier, values less than 1 add fuel, values greater than 1 remove fuel. Remember too rich is piggy, but too lean is engine death!
Mass airflow metering within the EEC is a function, value pairs (x, y), where x = voltage and y = air-mass. Mass air metering is not a subject I am prepared to teach. What I share below are my own thoughts and
opinions only.
Many aftermarket MAFs, such as Pro-Ms and even Fords, alter the voltages that are relayed back to the EEC. This is how the MAFs are "calibrated" for larger fuel injectors. This technology belongs in the same catagory as FMUs. Tuners can properly inform the EEC of changes and not resort to fooling the EEC with invalid input. Complications occur as a result of these invalid inputs. The EEC goes right ahead with its normal calculations. Load values are where the problems show up, but this discussion is beyond the scope of this article.
The MAF function value pairs from the U4P0, shown below, differ from the value pairs of the J4J1 processor. The GT's mass-air 'y' values, here, are larger per voltage than the Cobra's values. The GT's MAF is a bit smaller than the Cobra's. (GT MAFs are 55mm before removing the post, 67mm after, Cobra MAFs are 70mm). The reason the mass-air numbers are larger in the GT than the Cobra is the size of the injector each has to work with. GTs have larger numbers to coerce more fuel out of the 19lb injectors. Cobras have smaller numbers than the GTs and larger injectors.
Manipulating the MAF_FUNCTION without a roadmap, I did the following myself.
After removing the post from my MAF, building and installing a 9" K&N cone in my fenderwell with 3 & 4" pvc tubing back to a new 65mm throttle body and ported GT-40 intake(s), and installing ported GT-40X heads, 1-5/8" headers, and 2.5" H-pipe, I realized mass-air was greater than the meter knew. I input mass-air 'y' values which were approximately 10% greater than stock values. This cured my lumpy-lean idle. The EEC was being informed of a greater amount of air incoming and compensated with more fuel. (You should know that this was all performed while I was still using 19lb injectors). It was quite easy. I know that the scientific community might roll their eyes at my cowboy attitude and assumptions, but it worked.
I have just installed 24lb injectors, so the idle is once again unsmooth. I have cut & pasted the MAF_FUNCTION from the J4J1 into my U4P0, since the Cobra uses 24lb injectors and a 70mm MAF. I have 24lb injectors and a 67mm MAF, so I will reduce the mass-air 'y' values a bit and see what happens...
CRANK_FUEL_PULSEWIDTH_MULTIPLIER_VS_TIME can be used to lower the CRANK_FUEL_PULSEWIDTH_VS_ECT values 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.
In stock form, the multiplier is 1. Change it to match the proportion of your new injector size to your old.
For example, if you go from 19 to 36 #/Hr. set the values to 0.53.
Changing this was crucial to getting my car start and idle unassisted after initial coldstart with 50 #/Hr injectors.
The STARTUP_FUEL_TABLE uses bigger numbers to richen the mixture.
Adding timing to CLOSED_THROTTLE_SPARK_ADDER is sometimes required for engines running non-stock camshafts.
IDLE SETTINGS
Programming the idle using EEC Tuner is quite easy.
There are three variables that are used to set the idle.
Values for these variables are desired rpms.
MAX_RPM_CLOSED_THROTTLE_IDLE 750 # Maximum RPM for closed throttle idle NEUTRAL_IDLE 752 # Neutral Idle RPM
DRIVE_IDLE 600 # Drive Idle RPM
Neutral idle speed is set here to 752rpms.
Drive idle is at 600rpms; it's the idle for automatics at stoplights.
Max rpms when the throttle is closed is the range you allow idle hunting.
A quick tip:
I was able to align my tachometer using NEUTRAL_IDLE. Here is how:
1) Set neutral idle to 750; exactly between the 500 & 1000 rpm lines.
2) Download the idle setting and start the car. Wait for closed loop
operation -- the idle usually drops a tad.
3) Look at the tachometer in the dashboard panel. If it is not mid-way
between the 500 & 1000 rpm lines, twist the idle adjustment screw until
it is perfectly mid-way..
TIP IN RETARD (During shifts)
Timing is retarded by 5 degrees during shifts. You can eliminate it by setting the scalar:
TIP_IN_RETARD to zero from the stock setting of 5.
Mini Tech Tips: Lean or Rich? CHIPS and EEC Replacements / EEC - Tuner
Theres always someone asking about chips, programmers and EEC replacements. So i thought it wise to try and explain some basic theory about each kind of hardware.
For the first timers, let me explain a bit about the EEC or PCM.
The EEC is basically the brain behind the engine. Their programming controls fuel delivery, timing, transmission operation and many other engine functions. That sounds simple, but it is not. The EEC has to adapt to many driving habits and conditions and to do so relies on external Sensors and Actuators to "sense" and "change" engine operation.
Sensors are the "eyes" of the EEC, Actuators or selenoids are the "tools" used by the EEC to change engine operation.
Sensors: Air temp, Oxigen, Air Mass, Water temp
Actuators and Selenoids: Fuel Injectors, EGR valve, Distributor HAL sensor, KNock sensors, etc.
Now, each EEC model uses a "program" that reads the sensors input and accordingly will change selenoids and actuators operation.
How do "chips" work? simple, most chips work by "intercepting" the EEC signals and in an instant will replace their values with others. So basically most chips are only "fooling" the EEC.
This is not perfect but it works amazingly well for most engines.
Replacement EECs (Speedbrain , DFI) will replace the stock EEC entirely. They can use most of the stock sensors but many times they are geared for extreme performance engines so they forget entirely about all emissions sensors and actuators. In most cases the MAF is eliminated (DFI). These systems are more suitable for very high performance engines that dont need or care about the extra complexity of being emissions friendly. And as such they perform their function faster than stock EECs. These systems are not EPA legal to use on pollution controled vehicles (off road use only).
Theres also a "new" EEC gizmo in town: the PROGRAMMER or TUNER.
These are basically regular chips with special hardware that allows a user to reprogram the chip without removing it from the car.
But we have 2 flavors of tuners: those that allow a user to change almost every aspect of the EEC program (TypeA) and those that only change a few parameters (TypeB).
TunerTypeA: these are extremely well designed products of which 2 are the most famous: EECTuner and Tweecer. Both systems are very flexible and allow you to change the programming of EEC IV and V systems.
They also support "real-time" dataloging in some processor models.
The Tweecer RT model even has the necessary hardware to store more than 1 program.
TunerTypeB: lets skip these for a moment.
Now lets go to regular chips: basically these chips do the same as Tuners, and are reprogrammable also but with special programs and hardware that is not sold to the public, but here we have 2 "flavors":
Those that are "burned" or reprogrammed by a specialty shop using a dyno and those that are burned in high quantities using "pre-cooked" programs. Lets call the first ChiptypeA and the later ChiptypeB.
So you might ask, if they are basically the same which do i buy?
And here are some answers:
TunerTypeB: will only change a few parameters and they could be as expensive as type A Tuners but their program is limited to change only a few parameters (Hypertech power programmer).
ChipTypeB: as i said these chips are burned in high quantities with "pre-cooked" programs that are suitable for stock engines. They would modify only a few parameters like timing, a bit of fuel tuning and automatic transmission operation (shift firmness mostly). Hypertech and Superchips sell these "mail order" chips.
So you may ask: are Hypertech and Superchips chips bad?
Not at all. Many tuners use Hypertech and Superchips chips, but the difference is they have the tools and knowledge to reprogram them on a dyno for your specific needs and modifications.
The ones you must stay away from are the "one fits all" mail order type of chips, doesnt matter what the brand. They do provide some degree of increased performance, but the gains in HP are cheaper to obtain with other modifications. These chips CAN BE reprogrammed by a specialty shop though.
So to round up: Tuners like EECTuner and Tweecer are great buys if you know what you are doing. Their learing curve is steep but the rewards are many if you are a hardcore user.
Dyno made chips: You need a reliable shop with a dyno and some extra cash for each dyno session. These chips then are worth every $.
Downside: If you make more modifications you will need to take your car again to the shop to get the chip reburned.
Tips: Hypertech and Superchips chips can be REPROGRAMED, if you know of a shop that can burn them and you find a "mail order" chip for low $ (100 or less) you can take it to be reprogrammed for your needs.
One more thing...if your car is mostly stock or would stay mostly stock, find that extra HP elsewhere. The most you can get on a stock 4.6 or 5.0 is at the most a 15hp increase with a good chip.
ANY chip or tuner is just as good as the program in it.
Well, i hope these tips help some of you
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Rob Hernandez, AFM
Last edited by ScottHalliday; 06-12-2006 at 07:30 AM.
Thanks Rob.....I have a 98 GT with AODE and am intrested in learning about tweaking. I had wanted a SB system but I read somewhere they are on the out......is this true? Is there anything I can do to reprogram stock eec? Where should I go to start learning?
I was involved with a tech article this last week at AEM in Hawthorne, CA. They have a plug and play, programmable engine management system that is now available for '86-'93 and '94-'95 as an EEC-IV replacement. I got 30HP without really getting into it hardcore yet! There will be an EEC-V system available soon! Tuners should get this one. Ther are so many diferent aspects to this system, your head COULD spin...
Originally posted by Emery Thanks Rob.....I have a 98 GT with AODE and am intrested in learning about tweaking. I had wanted a SB system but I read somewhere they are on the out......is this true? Is there anything I can do to reprogram stock eec? Where should I go to start learning?
Originally posted by GTRaptor Maybe AEM can provide us with a unit for testing?
That could be great
They have already provided me with one for testing...
The editor for 5.0 Mustang is a dyno madman and he will be testing on his end as well on many dyno pulls with many different combos...
so watch out for June or July issue for the first article...
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"Mad" Max
1992 LX, thanks to Chicane Sport Tuning and some friends.. it is now wrapped with new graphics and ready to hit the streets AGAIN!!!!
Wow, that was some great info. I have been pondering on a chip or programer for quite a while. I just got a new (new to me) stang and have been thinking about getting a chip but don't know what would be best for my stang. Dallas (Dallas Mustang) is prob. were I would have to go for a burned chip, thats the closest place from me that deals with serious performance, what do you think is the best choice for me, my mods are on my sig, also want to throw a wet NOS kit on, will that change things if I get a chip and then spray. Thanks for any advice!!
Originally posted by SickStang also want to throw a wet NOS kit on, will that change things if I get a chip and then spray. Thanks for any advice!!
Depending on the program the EEC should be able to compensate to a point. For example, when the botle presure drops below a certain point but the fuel pressure for the wet nitrous system remain consant the EEC will decrease the flow output from the injectors to compensate for the increase in fuel flow. When the EEC reaches a point when it can no longer compensate, the computer will change certain parameter(s) to what it think the engine should be doing(ei: will retard timing). It usualy results with very poor performance.
In other words. Keep the botle full and you'll be fine
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Black,79 Mustang mostly carbon fiber/kevlar body, M-2300-k brake kit, full roll cage, maximum motorsport suspension, custom geared 6 speed, 2 inch rear fender flares, 1 inch front, motor being built (no eta). Looks like the Mad Max interseptor and weighs about 1800lbs w/o motor (450hp 351w installed to move the car around)
Black, 82 Capri RS 5.0L, B303, 1.7 rockers, World 180 heads, +150hp N.O.S, Turbo coupe rear end, T-56(tremec tko would be beter), 80 cobra nose
Well I am thoroughly confused about what to do now. Besides not knwoing which route to go with my computer I had another question. Does anyone know anything about this resistor: http://cgi.ebay.com/ebaymotors/ws/eB...474747129&rd=1
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'96 GT, Auto
Steeda Underdrive Pulleys, Densecharger Cold Air Induction, BBK 70mm Throttle Body, Phenolic Intake Spacer
The resistor will change the Intake Air charge temperature readings, and by doing so will change the fuel mix and timing, i definately dont recommend it if you dont know what to expect, your car will run on the lean side and with more timing advance, and if you dont know what you are doing you can experience servere detonation. It is a "poormans" way of increasing performance.
The Air/Fuel ratio and how it's burning can be read on the ceramic portion of the spark plug. A ring can be seen where the effective heat transfer takes place. The closer this ring is to the tip, the richer the mixture. The Closer to the base of the plug, means the engine is running leaner.
And I learn something new everyday... Do you happen to know where I can read a full write up on how to read spark plugs?
Here's about the best way to find the heat range you need and tune air/fuel. The base ring shows A/F mixture more accurately than the porcelain, which tells more about ignition timing.
Mini Tech Tips: Lean or Rich? CHIPS and EEC Replacements / EEC - Tuner FAQ 
