Modifying a Motronic Unit (Good Luck)
06-27-2012, 09:09 AM
#1
Instructor
Thread Starter
Modifying a Motronic Unit (Good Luck)
I was asked this by a Rennlist member and after spending a year attempting to modify a Motronic unit, this is the limit to understanding of this antiquated system:
I have a ex- european GT car that was imported to the USA in 2001 that appears to have a very similar engine setup to your own. It still has a Motronic ECU.
I believe it is setup to run Alpha-N but I'm having some trouble with my idle -- it is very lean. The only inputs to the DME/ECU appear to be the lambda/O2 sensor and a Throttle Position Sensor. I'm guessing (but I don't have the tools to really know) that the TPS is feeding the sensor input that on a normal 993 DME would be expecting to see the AFM signal. Is that how yours is setup? Do you also run Alpha/N mode? Do you have any advice on east coast tuners who know how to set up Motronic for racing motors?
And my rsponse was:
At the suggestions of many, I was advised not to use the original motronic however my goal was to return the car to it’s original spec. You are handcuffed with Motronic. What little you can do with the TPS will be adjusted internally by the chip every time you make an adjustment. We really fought with it for quite some time until we basically tricked it using the Bosch Hammer for acquiring the settings and lots of beer.
One question, do you have the proper motorsports chip?
Here is a picture of what it should be. This is a Supercup chip.
The only way I know, and have been told, to really tune the car is go to Motec and then you can map everything.
Does anyone have adidtional info to offer?
I have a ex- european GT car that was imported to the USA in 2001 that appears to have a very similar engine setup to your own. It still has a Motronic ECU.
I believe it is setup to run Alpha-N but I'm having some trouble with my idle -- it is very lean. The only inputs to the DME/ECU appear to be the lambda/O2 sensor and a Throttle Position Sensor. I'm guessing (but I don't have the tools to really know) that the TPS is feeding the sensor input that on a normal 993 DME would be expecting to see the AFM signal. Is that how yours is setup? Do you also run Alpha/N mode? Do you have any advice on east coast tuners who know how to set up Motronic for racing motors?
And my rsponse was:
At the suggestions of many, I was advised not to use the original motronic however my goal was to return the car to it’s original spec. You are handcuffed with Motronic. What little you can do with the TPS will be adjusted internally by the chip every time you make an adjustment. We really fought with it for quite some time until we basically tricked it using the Bosch Hammer for acquiring the settings and lots of beer.
One question, do you have the proper motorsports chip?
Here is a picture of what it should be. This is a Supercup chip.
The only way I know, and have been told, to really tune the car is go to Motec and then you can map everything.
Does anyone have adidtional info to offer?
Last edited by wpgt3cup; 03-18-2014 at 05:31 PM.
06-27-2012, 06:00 PM
#2
Technical Guru
Rennlist Member
Rennlist Member
All the Bosch ECUs have modifiable flags for sensor correction (i'm always amazed to watch "tuners" dyno tune/mess with partial throttle mappings without disabling the O2 sensor correction...) Did you ever dump the EPROM? If so, I could do a quick disassembly for you. The sensor ADC channels and mappings were pretty standardized between the model years.
06-27-2012, 06:17 PM
#3
Addict
Rennlist Member
Rennlist Member
Slightly off-topic (and no desire to hijack this thread), but it sure would be nice if these earlier ECU's captured and supplied data channels like the later Bosch Motorsport ECUs do. I'm not look fg for CAN Bus, I'd be happy with RS-232 feeds! The 2001 Cup has a Bosch Motronic M5.2.2 ECU and trying to get ANY INFORMATION on it is like pulling hen's teeth!
If there are sources of information about my particular ECU (Bosch Motronic M5.2.2) floating around, I would sure appreciate those poniters!
If there are sources of information about my particular ECU (Bosch Motronic M5.2.2) floating around, I would sure appreciate those poniters!
