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Old 02-15-2006, 04:06 PM   #12
crazymikie
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Member#: 56321
Join Date: Mar 2004
Chapter/Region: NESIC
Location: Hopkinton, MA
Vehicle:
2006 Honda El Camino
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Quote:
Originally Posted by JRSCCivic98
Way off base on both of these. IAM goes to initial value after a reset. If there is no knock the IAM advances from 8 to 12 to 14 and finally to 16 on a stock tune. With Cobb's initial value being at 12 the advance goes to 14 and 16 after only a few miles. The only time the IAM drops is if there was knock with the level of KC in the KC maps that the IAM references...
I don't understand what that last statement means. Your IAM affects timing for the overall KC map. There is a finite range that it is programmed to learn over (rpm/load) and I'm not sure if Cobb modified those values or not. In any case, it's very possible that your IAM doesn't move around at WOT, based on how much load your car is seeing. Your IAM could settle at 12 because of how the midrange of your car is tuned. If your tuner accounted for this and set up your timing at WOT to run that way, what is wrong with this? I personally don't do it but some other people may.

Quote:
Originally Posted by JRSCCivic98
if the IAM stays low and steady then the ECU has found the safe KC values to run without causing any knock. If the IAM was to go higher different KC values would be referenced and run... hence the low KC value number on a low IAM and high (10) on an IAM of 16. That's what KC values are based on... Some tuners mod the KC value tables, some don't. The good ones do and know what they are doing to find that sweet spot in the the timing curves.

Telling someone that if their curves are good even with crappy KC values and low IAM is not good advice. IAM should always be maxed at 16 with a proper tune.

pottymouth, go to the Tari forum and read my post. It'll steer you in the right direction.
No it shouldn't. Some people leave headroom in case they add race gas to their car. With pump gas, their IAM may settle at 10, but with race fuel, it might advance to 16. There's nothing wrong with that if it is tuned correctly. I personally prefer a different mapping but that's me. If the car is running the proper amount of timing and not detting with an IAM < 16 it's reasonable, though. The IAM is a coarse adjustment. It gets things in the ballpark and seems like it settles after a bit of driving. Then the knock correction and finally fine learning can take over and do their things.

I'm not saying one method is right or wrong- they have their advantages and disadvantages.


Mike
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