DME Remapping
#16
Burning Brakes
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The "spirited drive" is not a myth - like someone else said, it just hits more of the cells in the rpm/load table so that the DME can make the appropriate fuel trims. The trims aren't "much", however, and even if you didn't do the sprited drive you'd hit those cells eventually and the DME would adjust the trim appropriately at some point. The whole idea behind the spritied drive, I think, is just to get the trims set sooner rather than later - by trying to hit as many cells as possible in the map. I doubt you could feel any of this in the seat of the pants, though. Our Motronic version cannot adjust the trim by "much", and it takes a relatively large fuel mixture change to notice anything in the butt dyno. Don't know "how" much in a 4-stroke, but in my 2-stroke kart you notice a little bump in power when you get the mix just right - there is definitely a sweet spot - but we're talking relatively big adjustments in fuel mix (starving to drowning), bigger than the DME can make via trims.
#17
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"The trims aren't "much", however, and even if you didn't do the sprited drive you'd hit those cells eventually and the DME would adjust the trim appropriately at some point."
Very questionable theory!!!!!!!!!!!!!!!!
There isn't a TRIM value for each cell and the TRIM value is NOT used to maximize
the torque, ONLY to keep the O2 emission system within its ideal operating
range. As an example if the fuel pressure slightly increased.
But, if you still think the "drive" makes it better, then you're free to believe "whatever".
Some still believe Elvis is alive.
Very questionable theory!!!!!!!!!!!!!!!!
There isn't a TRIM value for each cell and the TRIM value is NOT used to maximize
the torque, ONLY to keep the O2 emission system within its ideal operating
range. As an example if the fuel pressure slightly increased.
But, if you still think the "drive" makes it better, then you're free to believe "whatever".
Some still believe Elvis is alive.
#18
Instructor
Join Date: Jun 2003
Location: Pretoria, South Africa
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I have disconnected the DME on my car numerous times. I have never noticed any change in behaviour whether the car was driven "spiritedly" afterwards or merely sat idling to warm up after starting up.
#19
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A long time ago (this has been discussed several times before) I asked what happened when people bought the car from new if this spirited drive was necessary. Were they told that they should take their brand new engine out for a spirited drive just so the DME could learn what it needed?
Didn't seem very likely to me.
Nobody answered me either.
Didn't seem very likely to me.
Nobody answered me either.
#20
Rennlist Member
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Just to put my experiences with adaption.
When My cars engine went bang not being Bill gates it was a big problem. just to repair it cost more than my previous car!
Anyway I was **** scared that the same thing would happen again so I read through all the forums and decided that I would minimise the risk of the DMF taking out the engine if it failed by fitting a LWF at the same time.( I did not know the full ramifications of this)
Now this is were the relevence to this thread is. My car ran great for thousands of miles but then the battery went down. I replaced the battery and all was well again. apart from one thing. the car stalled every 2 frigging minutes.
My mechanic did the system adaption and all was ok again. so the adaption makes a bg difference to my car. hence the questions about this and the scantool.
When My cars engine went bang not being Bill gates it was a big problem. just to repair it cost more than my previous car!
Anyway I was **** scared that the same thing would happen again so I read through all the forums and decided that I would minimise the risk of the DMF taking out the engine if it failed by fitting a LWF at the same time.( I did not know the full ramifications of this)
Now this is were the relevence to this thread is. My car ran great for thousands of miles but then the battery went down. I replaced the battery and all was well again. apart from one thing. the car stalled every 2 frigging minutes.
My mechanic did the system adaption and all was ok again. so the adaption makes a bg difference to my car. hence the questions about this and the scantool.