993 ECU chip maps?
07-02-2001, 11:00 PM
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993 ECU chip maps?
OK this may be a little too nerdy for this forum but can anyone share some info on map locations and parameters for a pre-varioram 993 so I can reprogram EPROM? I have the equipment figured out but not where to find the maps in the EPROM. For example, what is rev limiter byte address? Is there a technical bulletin from Bosch on this topic?
07-03-2001, 10:01 PM
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The tuners I know would never give out that kind of information because it's Intellectual Property, and it cost them to get this info.
Also, the tuners also understand the 3-D mapping with regards to fuel delivery and spark advance [among many other things].
I have been an electrical engineer for over 25 years, and I wouldn't try to modify the mapping of these chips. Way too many things could go wrong. The OBDII systems are quite complicated.
Rick
[ 07-03-2001: Message edited by: Rick in Portland ]
Also, the tuners also understand the 3-D mapping with regards to fuel delivery and spark advance [among many other things].
I have been an electrical engineer for over 25 years, and I wouldn't try to modify the mapping of these chips. Way too many things could go wrong. The OBDII systems are quite complicated.
Rick
[ 07-03-2001: Message edited by: Rick in Portland ]
07-05-2001, 12:42 PM
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You'll want to figure out how to calc the check-sums before you make changes to the EPROM. Or you can disable the check-sum routine.
What maps would you like to change?
doug.boyce@hummingbird.com
What maps would you like to change?
doug.boyce@hummingbird.com
07-07-2001, 08:08 PM
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Doug:
Thanks for your feedback. I believe the editing software that came with my EPROM programmer provides the checksum update feature you mention. I am a Porsche enthusiast interested in understanding the changes made by a tuner to my original chip, and am trying to avoid running a byte-per-byte comparison of custom vs. original EPROM. Any primer on map locations & scale factor would be great. Specifically, rev limiter (single byte?), ignition and fuel map (16x16?) would be great. Fortunately for my 993, I don't plan on playing tuner!
Thanks,
Dave C.
Thanks for your feedback. I believe the editing software that came with my EPROM programmer provides the checksum update feature you mention. I am a Porsche enthusiast interested in understanding the changes made by a tuner to my original chip, and am trying to avoid running a byte-per-byte comparison of custom vs. original EPROM. Any primer on map locations & scale factor would be great. Specifically, rev limiter (single byte?), ignition and fuel map (16x16?) would be great. Fortunately for my 993, I don't plan on playing tuner!
Thanks,
Dave C.
