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Update 2007-01-20
This is the off-season for cars like this unless you enjoy ice racing. The engine has been dismantled and revealed broken ring lands and signs of detonation on cyl 1 and 6. The other pistons looked ok, but could've run a little cooler. The reason for the broken ring lands is something I need help to resolve, I think I already know why! The rpm in the logs below reveal that all is not well due to the jagged appearance of the rpm signal. Unfortunately the opportunity to make a trigger log on this particular setup is lost as the engine is in pieces and so is the car. We had no wheel errors but something else was off. I will test the particular VEMS Genboard that was used on my "test" engine later this year to see if the problem persists. The exact same settings for the trigger has been used on several other BMW engines of the same model and trigger setup and revealed no problem with the rpm signal. My belief is that what has happened is too much ignition advance on cyl 1 and 6 only. The other cylinders probably had the correct advance. We measured EGT at the cyl 6 exhaust port and could never reach very high EGT (700C, no more) and this is probably due to the high ignition advance. Had we measured in some other cylinders the problem might have been revealed as the other cylinders have signs on the piston tops of running hot as the surface around the intake valve is very clean from deposits - or so people tell me. Could I get help to confirm my suspicion? ---- |
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Update 2006-07-19 Sometimes when looking for something you are blinded by not double-checking what worked before. It seems something crawled up and died inside the inlet of the intercooler. :-) I never thought to look at the MAP gauge in MegaTune before - last night I noticed straight away that something was wrong. It never showed more than 80 kPa while free revving the engine - it should be close to 100 kPa (atmosphere). We removed the pressure pipe from the inlet of the throttle body and the engine transformed, it really woke up (night and day) when we removed this restriction. I'll be back tomorrow with a tuning update. ---- |
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Q: How to enable shiftcut? Through grounding of MCP3208 pin 7? I can't find a good reference information on this. I will update Wiki accordingly if the answer is given here. |