ignition advance map zeroed
 

hi. is it possible to zero-out the ignition advance map so no additional timing would be added through the IAM on top of the ign base map?


:thanks:

Yes, IAM will stay at 1 and FLKC is disabled IIRC. Quite why you'd want to do it though....?

Not really sure why you would want to do that. If you get a bad batch of gas it could save you a bit of trouble.

I don't see a reason why you couldn't, but you'd have to change the base timing to match of course.

Wouldn't it be effectively disabling FBKC as well ? its used to decrement IAM.

IAM would be effectively disabled

would FBKC still be active up to its set limit like -5 but it would never decrement IAM ?


Mr visconti does this i believe in some tunes his KC Learned was zero

I thought flkc and fbkc were straight additive degree values with their own parameters. If rough correction (IAM) is disabled, then you are always in fine correction mode?

Not really sure why the flkc and fbkc would be affected based on my limited knowledge. Is there some logic I am missing? Not trying to argue with the gurus here, it it just doesn't make sense to me.

...on the other hand, if rough correction isn't disabled, and just ineffective, you could find yourself in limp home mode I think.

Most of what I know is from here.
http://www.romraider.com/forum/topic1840.html

FLKC is related to the advance table, you can't get larger retard (or advance) values than in the table. Therefore you don't get FLKC where the advance table is 0. It would mean that only FBKC is active.

The car will run fine, if you don't need/want rough correction then it's a solution that would work. I'm not sure why you'd take that away though as it's there for a reason.

for my understandings the ignition advance map will add that amount e.g. 6deg of timing on top of the ignition base map. so if IAM 1 the ecu will add 6deg on top of the base map. IAM 0,5 it will add 3deg is this right? I dont want the ecu to add timing out of the ignition base map.

thanks for you answers!!

Yes, and it's known as course correction. The idea is that the advance map has larger values in knock prone areas so that if the IAM reduces then more timing is removed. Look at the OEM map to give you an idea.

This is why most tuners will set ghe iam initial vzlue to 1 and not 0.7 like in stock tune. Tgis way each time car is turned on it runnong max timing and the ecu will only reduce timing in event of knock and it gives yo max potential to reduce timing and nons will be added.

With stock tune and iam initial at 0.7, after start-up if thier is little or no knock ecu will advance the timng by incrememting the iam towards 1.

Think its best to leave some timing in ghe knock correction table and just set iam initial to 1? This way yo have maximium abbility to combat knock.

I dont see any reason to effdctifly disable one of ghe ecu main defenses against knock.

Also when iam reduces below 1 the ecu also adds fuel using the additive fuel table this also aids knock correction

Yes one of the first things I did was 0 out this map. I want a set timing, I don't want the computer changing it unless I get knocking and I have my knock retard pumped up. I also data logged and back the timing down till there is no more correction so I have perfect timing...

Much more consistent power...

But the ECU does this even if it's not set to zero....

I zero out the advance map and just run the base ignition map at the timing I want so I always have the timing I want. I want the same power at all times I don't need the ecu to learn for me. I also run the the most timing I can without knock corrections so I make the most and safest power on pump gas. I also bumped up my knock correction, so if I get knock I don't break anything, but my timing is perfect so it's more of a fail safe for bad gas.

Was thinking the same way. I dont want to the ecu "maipulate" my timing tables with iam.

TBH that's the only thing the IAM is there for. I run with a decently populated IAM table and it rarely makes corrections. If it does then it's going to "lose" me less than your knock retard values, as 3% of 5 degrees is minimal. I do however have the backup of it being able to globally pull timing if I have bad fuel, although that rarely happens here, rather than it constantly pulling FBKC.

I can see why you'd run like that, but if your car runs without making any corrections then it shouldn't pull the advance multiplier down either.