A9L2 Base Calibration
by Michael Decipha Ponthieux
Last Updated: 2021-03-10
The A9L2 base calibration can be used
in lieu of the following factory calibrations.
Note: Strategy swaps require Moates hardware.
Decipha's custom GUFX strategy is a derivative of the original ford GUFB strategy. This strategy and the following A9L2 calibration can be used to replace the following cal codes: A3M, A3M1, A3M2, A9L, A9M, D3D, S0Z, X3Z, the GUF1 cals- A9P, A9T, C3W, C3W1, and the GUFA cals- 8LD, A9S, A9S2. This strategy can also be used on 4 cylinder engine with the proper changes and can replace the GURE strategy for the 89-90 super coupes with cal codes- A0H0, A9U2, A9Z2, C0S, L0E1 using the base supercoupe cal L0E2 available upon request.
What is the A9L2 ?
The stock foxbody calibrations are not optimal by any means. Henry's engineer's working on the foxbody calibrations obviously did not fully understand the functioning of the ECU's or were not communicating between groups. This is evident by the 'band-aiding' they did to the fuel table and WOT multiplier to get fuel where they wanted it. The stock calibrations require extensive changes in order to successfully calibrate a vehicle even in completely bone stock form. The A9L2 base calibration is a theoretical stock calibration for the foxbody ecu's created by decipha. This base calibration is adjusted for highly modified naturally aspirated, boosted (turbocharged, supercharged), nitrous and even bone stock factory engines all in one. Decipha's A9L2 can be used on ALL 1989-1993 foxbody mustang ECU's. However, for Tweecer users you cannot change strategies. If you have a tweecer and wish to use this calibration first you must verify your ecu is a GUFB strategy ecu. TunerPro does not support reading or writing from the tweecer. Thus it is recommended to use tunerpro to edit your tune and write it and datalog with caledit using the gufb strategy. Caledit can open tunerpro 56k binary tune files with no problems as well as most other softwares auch as eec editor and binary editor. However due to the custom code and moved and relabeled functions and parameters scattered throughout the A9L2 it is not recommended to modify this cal with any other software besides TunerPro as you may be inadvertently changing a different parameter.
The following changes have already been done in the A9L2 calibration:
The following custom code is incorporated in the A9L2 calibration which separates GUFX from the original ford GUFB code.
- Overheat protection shuts off the engine when your engine temp reaches 244 degrees; and allows ~12 seconds of run time after restart so you can move the vehicle if need be. This is done with FN320A forcing OL at 244 deg, FN1362/FN1307 [Base Fuel / Primary Fuel Table] commanding maximum lambse and FN1306/FN1361 [Startup Enrichment / Lambse Subtractor Table] allowing approx 12 sec of startup fuel. Do not change the 0 Perload values in FN320A or the last column values or the scaling for either of those tables.
- Backflow has been maxed out disabling the airmass clip.
Adaptives have been simplified and set to correct quickly.
Spark has been simplified to the FN2200 spark table.
Fueling is simplified to FN035A the peak load at 0 vac and 0 boost function.
Simplified idle control does not require idle air to be dialed in. Simply adjust the throttle stop at a warm stable idle to get the iscdc below 35%.
- MAF Voltage Clip - reduced the top of the maf from 16 volts down to 5.12 volts without causing corruption.
- 2-step Code - Enables the 2-step rpm limiter when the clutch is pressed, vehicle speed is 0 or brake pedal is pressed. Is also used during no lift shifting to help lessen the stresses during wot flat foot power shifts.
- FN1035 table is only used during closed throttle to allow the table to be used to correct decel fueling for those with noisy mafs or booted setups with bypasses and blow off valves that backwash the maf on decel.
- FN035A function replaces the FN035 function giving a much larger function for more accurate fuel control.
- FN338 function replaces the LOLOD scalar with the FN338 function used in newer strategies. Unlike newer strategies this function operates even when the warm hego and stabilized fuel flags aren't set.
- NIOLD scalar input is changed from the closed throttle neutral timer to the closed throttle timer to allow NIOLD to be set to force open loop after being at closed throttle for any amount of time regardless.
- FN071 Extended function increases the resolution of the function and the original FN071 function no longer exists.
- FNCRKMUL_FAR patch creates a cranking pw multiplier table similar to what exists on newer strategies for more accurate cranking pw control. The original cranking pw multiplier function FN306 no longer exists.
- Stabilized fuel table code was ported over from GURE by sailorbob "dex" over 10 years ago to give stabilized rpm and load based fuel control as-is present on newer strategies. The stabilized fuel table FN1360 is not populated and disabled by the ECTSTABL scalar set to 254. To use this fuel control the table will need to be populated and the ECTSTABL scalar will need to be set to a reasonable value such as 160 or so.
- Stoich AFR scalar implemented by sailorbob "dex" is set to a stoich value of 14.079 for E-10 fuel. This scalar can be changed for race gas or different concentrations of ethanol. Keep in mind this is a global fuel multiplier and does not affect commanded lambda.
- Fuel pump prime time scalar is broken out and set to 3 sec instead of the stock 1 sec.
- The egr altitude table is inhibited with sailorbobs patch.
- The cranking spark advanced is changed from 10 degrees to 4 degrees to allow higher compression engines to start easier and to prevent startup knock on some high mileage engines that do not run motorcraft oil filters.
- WOT spark functions are disabled and assigned to n2o spark control. Although the n2o code is reserved for premium members the functions are disabled regardless. This patch varies from sailorbobs old wot spark inhibit patch from 10+ years ago and will show as corrupt in other software when it is in fact not.
- FN1133 x scaling input has been changed to ACT instead of ECT for more accurate ACT spark retard using the table and not a function.
- FN126 x scaling input has been changed to ECT instead of ACT for simplified ECT spark retard since ECT has a general effect on spark advance and requires less resolution than ACT.
- High speed fan output is assigned to a/c control. It used to be common for folks to wire up the high speed fan output and also wire it to the ac clutch so it came on with the a/c. Thats no longer needed as I have assigned the a/c to turn on the high speed fan in the code.
- Dashpot DASCTL control - newer strategies incorporate a DASCTL scalar to allow IPSIBR updates while dashpot is still being decayed to allow a seamless idle transition. GUFB was hardcoded to wait for 0 dashpot before allowing idle control. This patch disables that.
- FN824 x input is changed to vbat for inferred fan voltage drop compensation. This will allow the idle to respond to a voltage drop associated with a fan thats not pcm controlled preventing a stall on large voltage drops.
- Z_VPRG patch is created by sailorbob and disables the purge tests (code 85 fault).
- US_SWTPOINT scalars created by sailorbob for hego voltage threshold for switching is dropped from stock .4225 volts down to .3 volts for more accurate hego control when long tubes are present, cams with excessive overlap are used or poor grounding exists on aged wiring.
- DMA datalogging is already enabled.
- K-constant is already set to 30 and scaling percentage scalars allow unscaled actual injector and maf values to be shown as well as any parameter with SP** in the title.
The following are the absolute MINIMUM changes REQUIRED before starting your vehicle utilizing the A9L2 calibration. Be sure you input your variables IN THIS ORDER otherwise your values will be wrong!
Before manually entering your injector data in your tune check to see if the template exists at the bottom of the tree view in tunerpro. If so simply click the patch to enable the injector data in your tune. NOTE that anytime you change the injector data in your tune you MUST update all values in your tune that have SP** most notably SARCHG and the MAF Transfer.
|1>||K-Constant||Global Fuel Modifier||This scalar should always be set to 30 and never adjusted.
|2>||SP**AHISL||Injector High Slope||This is your actual injector data from the manufacturer.
|3>||SP**ALOSL||Injector Low Slope||Input your injector's manufacturer's data.
|4>||SP**FN389||Injector Breakpoint||Input the injector manufacturer's recommended fuel breakpoint.
|5>||FN367||Injector Offset||Input the manufacturer's recommended voltage offset values.
|6>||FN348||Crank PW ECT Modifier||Multiply the Y-axis as a percentage of the stock 302 cubic inch engine and stock 19 lb/hr injectors values by doing, 19/(new injector size) * (new engine size)/302=0.xxx Apply that 0.xxx correction to the entire y axis.
|7>||SARCHG||Cubic Inch Displacement||Input your actual engine size
|8>||FN035A||Perload Scaling||Populate the Y-axis with your engines expected peak N/A load values (when not in boost). DO NOT PUT IN MAXIMUM LOAD VALUES WHILE IN BOOST. This can be left stock and updated as your tune is dialed in.
|9>||SP**FN036||MAF Transfer||Input your actual MAF flow data from your flow sheet to begin tuning.
|10>||(Current) FN2200||Spark Table||Populate this table with adequate values for your specific engine combination. Reference the spark write up and mbt chart for ideas.
Obviously you still tune as you would otherwise the A9L2 is just to get you on your way much easier and faster. You are still required to dial in Fuel, Air, and Spark just as you would otherwise.
As with all decipha base tunes its imperative you read over the pre-tuning write up, the fuel write up, spark write up and the initial tune instructions. Also know that the post tune Instructions apply as well to all tunes.
Special thanks goes out to Derek Fenwick, a.k.a. "sailorbob" / "dex" for originally creating DIY tuning support for the open source community.
Click here to download the A9L2, GUFX xdf and datalogging ADX.
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