OK, I'm thinking of going the ghettodyne route, since I've got a OBD0 PR4 B18a. I figured maybe to start I'd run a 'standard' chipped program like Erick's or PYR. But I like the idea of doing my own program. I have both stock ROM code, and a few of the common codes out there. I have no problem doing the electronics work or programming the chips.

I'm looking for a methodology for how to create the ROM tables.

I was thinking something along the lines of:

Do a baseline pull with whatever program I use.
Then do a series of pulls advancing and retarding the ignition through a range of maybe +/- 4 degrees, 2 degrees at a time.

Then, with all those data points, go back to the ROM editor, and look at what ignition setting gives the best power for each RPM point.

For fuel, I just figured look at the A/F ratio and see where some needs to be added and removed, and try to adjust accordingly.

Anyone have any comments/tips? All comments appreciated. I'm sure I'm not the only one interested in this.

BTW, I'm still putting the motor together(taking forever) but likely will be:

B18A (OBD0)
Head milled 0.030 (so probably around 10.0 even compression)
Crane #12 cams
Very mild porting on head, port matching on I and E
Standard I/H/E

So, nothing too radical...

Thanks,
Haggar

 

I have seen the code writers on a few pages, But where do you get the stock code and other pre written codes for the ecu's?

 

I have seen some sites with stock rom codes. I have them for the PR4, just wondered if anyone could provide suggestions how to develop a custom chip.

I don't want anyone to give away secrets, just a base methodology.