LA964RS

I think Kevin can answer the boost control question. My understanding is its not "loose" montronics in that the ECU still does all its supposed to...if you go into an overboost situation it will still pull timing, etc. Good question though. Kevin probably has a response somewhere on this or the 996 board that could be cut and pasted here.

Jean

I think there might be confusion between 1) Motronic controlled boost vs. fixed boost and 2) switchable programming..

You can have switchable programming (2 or more different programs) with either, a fixed boost program or Motronic controlled boost program irrespectively.

To put it in different terms,

I run a boost controller on my car, and I have both a 1.1 Bar optimized program (or Chip or Eprom), and a 0.7 Bar optimized program and I could choose between them with a switch if I had one. When I run at 0.7 Bar, the timing and fuel tables will be optimized for those levels on the dyno, and the same applies for 1.1 bar, which will then have different timing parameters.

Another person has a Motronic controlled program (Manthey for instance), with both a 104 octane file, and a 93 octane program/EPROM, and he can choose between them with a switch, again, he will be running the best possible program with each octane level (within tuner tuning skills obviously).

The difference between programs will be fueling, timing, boost etc.. not boost alone.

As to the merits of fixed vs variable boost control, it is a different topic.

JasonAndreas

The stock non-OBD2 993 ECU eprom image (M2.1) has separate "mappings" for storing fueling, ignition timing, etc. that are switcheable with a jumper. There is no reason you can't replace the jumpers with a $5 switch wired to your dashboard.

ptuomov

Does that also include boost control settings/maps?

Basal Skull

From what I understood, the 1997 ecu is flashable but to do it through the obd2 port, the data transfer rate is so slow, it makes it not that practical. Also the technician who was working on this now 15 years ago had health issue unfortunately and was never finished.

ptuomov

This would only make sense if the ECU has jumper setup or “coding plug” that selects the maps that already exist inside the ECU. I’m not (yet!) familiar with the 993 Turbo ECU, but the older LH fuel injection and EZ ignition computers would have multiple fuel and ignition maps stored in them. A coding plug would jump the right pins thru the wiring loom to choose the correct maps for the country based on the fuel octane availability. Uploading new maps on the fly would not be practical, replacing the coding plug with switches for different fuel octane would IMO work. Noob speculation, of course.

Basal Skull

As far as I know, the 993 ecu does not have/store multiple maps.