A dusty little corner of the Internet: electronics, computer hardware and software, general aviation, 1980's Mopars, and related sundry.
This section is devoted to automotive-related electronics projects, which primarily apply to mid-80's Turbo Mopars. Many of my older projects reside on the MiniMopar Resources website. All of my more recent projects are documented here.
Posted on September 16, 2008.
09/16/2008: Version 60.17 (based on "Blueberry60") - Add timing back to AdvanceFromMapWarmFull so that retard window is from 2.5 - 10psi. Also add a couple of degrees before and after that. Scale FuelMonitorScaling down instead of up (duh) to try to match observed mileage. Set StartFuelCompBaro back to stock to try to address insufficient fuel at cold start. Change AdvanceFromRpms under 1500 back to original BB60.
Posted on July 07, 2008.
07/07/2008: Version 60.16 (based on "Blueberry60") - Revert ColdEnrichmentFuelCurveA back to stock since AIS changes seemed to address part of lean startup conditions. Remove more timing from AdvanceFromMapWarmFull to widen range down to -2psi.
Posted on July 03, 2008.
07/03/2008: Version 60.15 (based on "Blueberry60") - Increase boost goals/limits to 21psi. Fix lots of missing TBL entries and re-enable staging mod. Get rid of "2bar/3bar" table names to permit easier comparisons to Turbonator and stock cals. Revert AIS tables and FuelLeanoutFactorOffThrottle back to stock. Bump FuelMonitorScaling to compensate for observed fuel useage discrepencies. Retard timing between 0 to 15psi up to -10 degrees at 6psi in AdvanceFromMapWarmFull for improved turbo spool.
Posted on June 05, 2008.
To use any of these calibrations, you will need to get the necessary equipment and modify your Engine Control Unit (ECU). There are basically two ways to go about putting a calibration onto an ECU. You can either use a socketed EEPROM (electrically erasable programmable read-only memory), which must be removed and programmed outside the ECU, or you can modify the ECU so that the EEPROM can be erased and programed remotely ("flashed"), which requires the necessary software and cables. The ECUs actually come from the factory with EPROMs, which must be erased with ultraviolet light. The ability to flash the ECU is especially useful if your ECU is a SMEC (single module engine controller) or SBEC (single board engine controller), which are located behind the battery and have electronics that are buried in potting material. If you have a logic module (1987 and earlier), it is located in the passenger compartment behind the passenger-side kick-panel and is not potted.
If you intend to use removeable EEPROMs, you will need an EEPROM programmer. If you intend to use EPROMs (which I sometimes do), you will need an EPROM eraser. I own a Needham's Electronics EMP-10 programmer and a Datarase II EPROM eraser. If you plan to flash your ECU, then you will need a cable and interface, as well as somewhat more extensive modifications to the ECU. The interface is available as a kit from Chad Clendening. The modifications needed to flash a SMEC were documented by Graem Schmidt in his very useful document.
There is a nice variety of software forming around this effort. They are listed below (I have archived these locally, since these links are all dead):
Obviously, some modifications are needed to your ECU to facilitate installing custom calibrations. If you plan to use the removeable EEPROM method, you will only need a 28-pin socket and some extra EEPROMs (or you can just reuse the EPROM you already have if you have an eraser). You will then need to desolder the EPROM from the ECU board and solder in the socket. If you are not skilled with a soldering iron, then I would recommend finding someone who is. The boards are double-sided and can be tricky to work on without damaging the traces. If you are planning to flash the ECU, then you don't necessarily need a socket, but I would recommend one just in case the EEPROM gets fried. See Graem Schmidt's document for additional details about the modifications needed to flash a SMEC.
For the socket, you should at minimum get a low-profile, machined pin socket such as Digikey ED3628-ND or A409-ND. Preferably, you should get a low-profile ZIF (zero-insertion force) socket, such as Digikey 3M2803-ND or A347-ND. The ZIF socket makes extraction and insertion much easier and safer for the chip and the ECU board, though probably isn't necessary if you plan to flash. If you have one of the Mopar Performance ECUs, then you might get lucky as they are sometimes already socketed.
The EEPROM you need depends on the model year ECU that you have. The 1984 electronics are probably not suitable for custom calibrations. They apparently use bipolar PROMs (similar to PALs) and little has been done to understand them at this point (though that doesn't mean it is not possible). The 1985-1986 electronics use a pair of 16kx8 EPROMs (one for the code and one for the calibration tables), but they do not have a hardware timer and it doesn't take much to upgrade to the 1987 electronics, which were the best from the Logic Module era. These are the devices used on the various modules:
The 27C/87C series EPROMs require an ultraviolet eraser to clear them. The 28C series EEPROMs are erased by the programmer itself. The 128 kilobit size has been obsoleted by most manufacturers but it can be replaced by the 256 kilobit parts, which have the same number of pins. Therefore, the part you want to get for 1987-1989 electronics is the 28C256, 150ns, industrial temperature (-40 to 85^C) EEPROM, Digikey AT28C256-15PI-ND. If you don't plan to flash your ECU and have an ultraviolet EPROM eraser, you can get the 27C256 EPROM equivalent for about one third of the price (Digikey FM27C256QE150-ND). Since the 1987 logic module only uses half of the 256 kilobit part, you can connect the A14 pin (pin 1 on 28C256 or pin 27 on 27C256) to a switch that either grounds or raises it to 5V and program two, seperate calibrations in (i.e. street vs race or new vs previous cal).
Posted on August 30, 2007.
08/30/2007: Version 60.14 (based on "Blueberry60") - bump FuelFullThrottle point 2 down to 5800uS. Too lean during decel still, so move point 1 of FuelNoThrottle right and up 2 ticks to -14.2psi @ 10.00uS. Move ColdEnrichmentFuelCurveA point 4 from 58.8^F @ 1.19 to 58.8^F @ 1.21.