Making a Custom Cal

The fact that I have endevored to make all parts, and do all work on my car that I can short of purchasing tools costing a few hundred dollars each has brought me to attempt my own custom calibrations. There is a lot of black art mystique surrounding this process, and it has honestly seemed to be a very hush type of thing in the Turbo Dodge community untill came around. That is the first place that I found people openly talking about making their own cals, and offering them up to others for free, or the cost of the chip. This is just my perception, so take it for what it is worth.

I intend on documenting my process as I go, so that the casual observer will be able to follow along knowing nothing about making their own custom cals. I do have a relativly decent knowledge of how the LM controls things though, and I would be lost without that knowledge. I would recommend that you read up at to familarize yourself with chryco fuel injection before getting started. As with all of the other guys doing this, if you blow up your rig taking my advise I take no responsibility.

Step 1: Identify the problem.

I don't know jack about making a custom cal, but there are others who have gone there before me. Thus, I checked out Mopar Chem This is the recource for all of us LM guys. D-cal on yahoo groups is a better bet for those that have already swapped to SMEC and SBECs. Hence forth, I will deal solely with the LM, as that is what most on will be dealing with.

One of the first problems that I noted was the fact that my car was converted to GLHS electronics, which although similar to 87' TII daytona electronics does not have the same support for the cals etc.

Step 2: Address the problem.

After reading up on, I decided that the GLHS stage II LM would not be the best for me since it utilizes two chips, and I could not find a ton of info on their mysterious workings. The 87' turbo II daytona LMs (you can use a TI LM) have much more support for obvious reasons. Changing to the 87' TII electronics will only require me to swap two wires on the LM due to the fact that the GLHS conversion was done when I bought the car. I will be using 87' TII cals and such in my project, as the support for it will be much better. For details on the conversion check out the T2 conversion.

Step 3: Arm thyself.

I picked up a MP 87 TII tona' LM. I took the first offer that some one made me, and I was unsure if I could have used a TI LM at the time, so the cost was $90. Although you should be able to use any LM which utilizes the external MAP, and will be much cheaper.

I also picked up A soldering iron and a de-soldering iron from radio shack. Total cost: $18.88

I bought a Willem enhanced Eprom burner which will do any chip you could use for any of the chrysler computers from what I have read thus far. The burner and a 28 pin DIP zero interface socket (ZIF) from MCU mall cost about $70 shipped.

For the last piece of the puzzle, I purchases some SST27SF512 chips from Mouser along with three chips for my shadows SBEC for about $20 shipped.

As you can see, if I were a little more thrifty on the LM purchase, I would have come in well under the cost of a custom cal. The best part of doing it this way is that I won't have to send my LM back constantly for re-cals.

Step 4: Socketing the LM