Question

[Methodical]

I did some datalogging the other day and noticed EA recommends I change the part throttle MAF figures. Before, it was right on - at least I thought. Can the change in temperature (hotter air) necessitate a change to the MAF curve? If so then I guess I will need a tune for all seasons uhhh. The part throttle areas were lean between 1-4% (I think I am saying that correctly ) so I increased (richened) the volume in those areas. I made the changes and it actually feels better.

Edit: I'm thinking along the lines that you have hotter air than before but with the fuel being the same it causes a lean condition. Correct me if I am wrong. Sometimes things are the opposite of what you are seeing if you know what I mean.

 

[blksn955.o]

It could be adaptive kicking in.

You are clearing the KAM's when you load in a new MAFtransfer right? THis will sque the log.

 

[vristang]

I have noticed some differences between what EA recommends from one datalog to the next.
I think that what driving conditions the data is collected under makes a pretty big difference.

Was your data collected using the same driving cycles?

jason

 

[Methodical]

Yes, I always clear KAMs whenever I change anything dealing with the MAF. But, I have not datalogged or changed anything since February.

Yes, the driving conditions were similar. Lately I've been working overtime on Sunday's (there's no better part time job than overtime) and wanted to get my idle right so that I can use the AC, so I datalogged a normal drive to and from work one Sunday - from the suburbs (MD) to the city (DC) so that I can get every range of driving condtion - idle, part throttle and WOT (not to concerned w/WOT right now - waiting for WB) to see if I needed to change the injector offsets as Grady mention (based on responses from an earlier post) and just to see what's happening. There were no changes recommended in the idle area just the part throttle area.

 

[vristang]

I thought all that was needed for Voltage Offsets was Idle.

When I set mine all I did was park the car and gradually add e- load while datalogging.

Did I screw up?

My bat voltage does not increase over idle with no load. Does yours?

I am just trying to understand the process better.

jason

 

[blksn955.o]

I think load changes alittle at idle as timing changes to keep things stable, that and since he wants to work with the idle with the A/C on that will also add to the load as the extra force needed to move that system.

Are the maf transfer corrections fairly small or large?
If the current changes are giving you good .999x kams, and drivability is good, since you dont have a W/B yet its going to be alittle harder to be 100% on the transfer/slope thing.

I would focus on the offsets as to what EA sug. to change them too if the changes are small and kams/drivability is good.

It is important to remember to focus on one area at a time otherwise you will go mad. I would make the sug. chainges to the offsets and DL and see if you then need to adj. the maf transfer to bring things as a whole back in line.

 

[Methodical]

Thanks. I have made the suggested changes - they were small ones and burned a tune to the TwEECer and sort of smooth out the slope. I have not use the tune yet. I will probably test on Thursday or Friday since I will be off of work. The car is not a DD.

Oh by the way, do I need to clear KAMs when I switch to the tune with the new Injector Offsets?

 

[BlackVert]

Oh by the way, do I need to clear KAMs when I switch to the tune with the new Injector Offsets?

it is not not strictly necessary, but it is a good idea to clear the kam whenever you change the maf curve, the injector slopes, or the injector/battery offsets

also, i believe the computer uses timing changes to control the idle rpms.