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Switchable ecu programs for 993tt?

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Old Mar 29, 2007 | 09:40 AM
  #16  
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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.
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Old Mar 29, 2007 | 10:23 AM
  #17  
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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.
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Old Mar 29, 2007 | 03:46 PM
  #18  
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Originally Posted by Jean
I would say that there are two ways of doing this on a Motronic based car, and you also have the option to go for a different solution with an aftermarket ECU such as Motec, Thielert etc..
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.
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Old Aug 2, 2022 | 12:45 PM
  #19  
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Originally Posted by 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.
Does that also include boost control settings/maps?
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Old Aug 5, 2022 | 03:46 AM
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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.
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Old Aug 5, 2022 | 04:19 AM
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Originally Posted by 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.
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.
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Old Aug 5, 2022 | 11:52 AM
  #22  
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As far as I know, the 993 ecu does not have/store multiple maps.
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