Real World Datalogging Via LM-2 Results
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Senior Member
Joined: Dec 2008
Posts: 343
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From: Taipei, Taiwan
C32 '02
Real World Datalogging Via LM-2 Results
After two nights of testing my new mods and datalogging them, here are my results.
I was kinda sad that our cars namely the C32 had a max sample rate of 8 samples/second. It uses the KWP2000 protocol which doesn't have a fast sample rating. Meaning the ECU will only update 8 sensors ONE time per/sec or update 4 sensors TWICE per/sec or 2 sensors FOUR times per/sec etc...
The C55 folks are in luck cause you guys have the newer CAN protocol. I'd be interested to know what the max sample rates are though.
The first attachment was my first attempt to data log 8 sensors. As you can see each of them only get updated once every second, not very useful for tuning imo. The afr has good sample ratings cause it doesn't use the OBDII, but connected directly to the LM-2.
Last night i went on another test run, this time using only 2 sensors:
rpm&speed, rpm&boost, & rpm&speed on WOT
From the data, i can clearly see where fine tuning is needed, e.g. 3rd gear 5400 to 6080 rpm its running a bit lean, then becomes richer for a brief moment until shifting ( Well, i'm no expert tuner so i don't know what is normal or what is not ...) the dip you see after is shifting to fourth gear where afr becomes 'normal'.
Max Boost I got was 20.17 psi @ 6110 rpm. ( 3rd gear ) So the headers did lower the max boost by almost 2 psi.
I was kinda sad that our cars namely the C32 had a max sample rate of 8 samples/second. It uses the KWP2000 protocol which doesn't have a fast sample rating. Meaning the ECU will only update 8 sensors ONE time per/sec or update 4 sensors TWICE per/sec or 2 sensors FOUR times per/sec etc...
The C55 folks are in luck cause you guys have the newer CAN protocol. I'd be interested to know what the max sample rates are though.
The first attachment was my first attempt to data log 8 sensors. As you can see each of them only get updated once every second, not very useful for tuning imo. The afr has good sample ratings cause it doesn't use the OBDII, but connected directly to the LM-2.
Last night i went on another test run, this time using only 2 sensors:
rpm&speed, rpm&boost, & rpm&speed on WOT
From the data, i can clearly see where fine tuning is needed, e.g. 3rd gear 5400 to 6080 rpm its running a bit lean, then becomes richer for a brief moment until shifting ( Well, i'm no expert tuner so i don't know what is normal or what is not ...) the dip you see after is shifting to fourth gear where afr becomes 'normal'.
Max Boost I got was 20.17 psi @ 6110 rpm. ( 3rd gear ) So the headers did lower the max boost by almost 2 psi.
