BMW M3 Forum
BMW M3 Forum BMW M3 Gallery BMW M3 Reviews BMW M3 Social Groups BMW M3 Chat M3Forum Sponsors >>
Loading


Mobile M3forum
Go Back   BMW M3 Forum.com (E30 M3 | E36 M3 | E46 M3 | E92 M3 | F80/X) > BMW M3 Discussions > E46 M3 (2001-2006) > Coding and Tuning
Tire Rack Buy Winter Tires Now!
Not a member? Register Now!
Register Gallery All Albums Garage Search Today's Posts Mark Forums Read Calendar FAQ

Coding and Tuning Discuss all avenues of coding and tuning here!


Reply
 
Thread Tools Display Modes
Old Mon, Oct-14-2013, 12:37:14 PM   #11
chris325ix
Registered User
 
Join Date: Jan 2012
Posts: 861
Reputation: 0 chris325ix is on a distinguished road

United States




Default Re: Fuel Adaptations Explained

any ideas on making it run with only 1 O2 input?

I've tested it a little bit but I haven't gotten past "no load controller" yet, so it's stuck in limp mode where O2 feedback isn't active. I'm hoping all I need to do is disconnect the sensor and disable the error codes, but I'm not sure if it will apply the bank 1 feedback to bank 2 or of it's hardcoded to bank 1 only..
Jump to top chris325ix is offline   Reply With Quote
Sponsored Links
Register now and remove these ads
Old Mon, Oct-14-2013, 12:39:00 PM   #12
chris325ix
Registered User
 
Join Date: Jan 2012
Posts: 861
Reputation: 0 chris325ix is on a distinguished road

United States




Default Re: Fuel Adaptations Explained

Quote:
Originally Posted by M3CARBON1 View Post
So depending on the health of the sensor each bank could have a different reading?!
not necessarily the health of the sensor but each bank could have a different reading due to slightly different air filling, injector spraying, burning, exhaust characteristics, etc.

ideally, you'd have 1 O2 feedback loop per cylinder but that's costly.
Jump to top chris325ix is offline   Reply With Quote
Old Mon, Oct-14-2013, 03:45:18 PM   #13
SliM3
Registered User
 
SliM3's Avatar
 
Join Date: May 2012
Posts: 2,564
In the garage:
Reputation: 0 SliM3 is on a distinguished road
Location: Atlanta

United States




Default Re: Fuel Adaptations Explained

Quote:
Originally Posted by geargrndr View Post
So you've set .3rf for the whole range... any thought to pros/cons of varying the load across RPM ranges?

Think I'm going to re-enable my adaptation error codes and try this out this afternoon...
You shouldn't run into any issues if you want to vary the load points at which fuel trims are applied. I like to use boost pressure in my analogies because that's obviously where a significant increase in air/fuel flow occurs.

So ideally you could pull a log of boost pressure at specific rpm points, from there determine the rf load where you see 0 psig, and stop fuel trims just before that point. Probably leave a little buffer so you can adjust for a nice transition.


Quote:
Originally Posted by Tchleung View Post
SOOO............. I just noticed now my tune has the "Lambda Adapatation Minimum Engine Temperature" set to 100*C(212*F) where as stock is 69*(156*F) My car NEVER reached 212*F coolant temperatures. Wtf? So maybe that's why my fuel trim adaptions have not been doing anything. It still thinks it's in warm up mode?
Indeed, yours have been disabled using the minimum engine temp constant. I wish we could start from scratch with your tune and get all those maps displaying true lambda/afr, etc.


Quote:
Originally Posted by M3CARBON1 View Post
Sli,

We really needed this so thanks. What would be the best setting, just set 0.00 for all?? And what is the difference between additive 1 and 2?
Well, it really depends on what you're after. If anything I would definitely adjust the Lambda Adaptation_Engine Speed map so trims aren't applied to the full load fuel map. If you have a pretty decent tune to your base map, say from 2000 on up, then you can either zero out the Lambda Adaptation Min/Max Factors or use the engine speed map to stop trims at your desired load point.
__________________

///M3 '06 Carbon Black

DEMOCRACY is two wolves and a lamb voting on what to have for lunch.
LIBERTY is a well-armed lamb contesting the vote.
-Benjamin Franklin


- Checksum corrections for modified DME partial & full bin files

- CSL SMG Engine Parameters (DME) by Slim

- Fuel adaptations explained

- Checksum Verification
Jump to top SliM3 is offline   Reply With Quote
Old Mon, Oct-14-2013, 04:02:11 PM   #14
geargrndr
Working for Nefarious Porpoises
 
Join Date: Jun 2010
Posts: 836
Reputation: 0 geargrndr is on a distinguished road
Location: AndoverRockport MA & Intl

United States




Default Re: Fuel Adaptations Explained

Quote:
Originally Posted by SliM3 View Post
Well, it really depends on what you're after. If anything I would definitely adjust the Lambda Adaptation_Engine Speed map so trims aren't applied to the full load fuel map. If you have a pretty decent tune to your base map, say from 2000 on up, then you can either zero out the Lambda Adaptation Min/Max Factors or use the engine speed map to stop trims at your desired load point.
Yeah, I really like this RF/speed function approach as the "right" way to do it vs the Min/Max. First it doesn't require zeroing the DTC's. Second as many engineers often point out to the alpha-N / speed-density crowd, one solid reason for keeping a closed-loop adaptations is to adjust for aging components as well as extreme conditions (ambient pressure / temperature) that fall outside the tuning environment. By keeping it in the low load points were you 'don't care' you let the car still make those adjustments while keeping manual control where you want it.
__________________
2003 M3CicM6 TiAg
2002 540iT Sport Vortech S/C 6MT LSD TiAg
2008 Audi A3 2.0T DSG (hers)
1999 Cherokee Sport 4L (trailer-hitched in-law loaner bomber)

Recently Former...
1995.5 Audi S6 Avant (utility/winter billetturbobattlewagen)


Jump to top geargrndr is offline   Reply With Quote
Old Mon, Oct-14-2013, 11:41:29 PM   #15
M3CARBON1
Banned
 
Join Date: Mar 2013
Posts: 300
Reputation: 0 M3CARBON1 is on a distinguished road
Location: London

United Kingdom




Default Re: Fuel Adaptations Explained

[/QUOTE]Well, it really depends on what you're after. If anything I would definitely adjust the Lambda Adaptation_Engine Speed map so trims aren't applied to the full load fuel map. If you have a pretty decent tune to your base map, say from 2000 on up, then you can either zero out the Lambda Adaptation Min/Max Factors or use the engine speed map to stop trims at your desired load point.[/QUOTE]

What are the benefits of doing this? How will it change the way the engine runs?
Jump to top M3CARBON1 is offline   Reply With Quote
Old Tue, Oct-15-2013, 07:18:13 AM   #16
Donkey1
Registered User
 
Join Date: Apr 2013
Posts: 265
Reputation: 0 Donkey1 is on a distinguished road

Germany




Default Re: Fuel Adaptations Explained

Are you sure fuel trims are applied to full load injection maps? Actually I can't confirm this because if I reset my adaptions and take some full load measurements with my wideband the lambda doesn't change at all even after some measurements.

I thought there is a comparison if the full load bit is active (full load = 1) and then fuel trims are disabled. Full load should start at 60% relative filling according to the maps. Someone posted the assembler code for this in the main thread I think?
Jump to top Donkey1 is offline   Reply With Quote
Old Tue, Oct-15-2013, 11:31:35 AM   #17
M3CARBON1
Banned
 
Join Date: Mar 2013
Posts: 300
Reputation: 0 M3CARBON1 is on a distinguished road
Location: London

United Kingdom




Default Re: Fuel Adaptations Explained

I heard that full throttle fueling doesn't adapt, it is part throttle only? This has come from a credible source too.
Jump to top M3CARBON1 is offline   Reply With Quote
Old Tue, Oct-15-2013, 11:38:31 AM   #18
Donkey1
Registered User
 
Join Date: Apr 2013
Posts: 265
Reputation: 0 Donkey1 is on a distinguished road

Germany




Default Re: Fuel Adaptations Explained

Full throttle fuel trim also makes no sense because a normal lambda sensor can't measure lambda values outside the range of 1 (AFR 14.7) and it is not wanted to drive at lambda 1 at full load.

That's why you have a specific full throttle injection map which is used at full throttle because then you have no adaption at all.
Jump to top Donkey1 is offline   Reply With Quote
Old Tue, Oct-15-2013, 01:09:39 PM   #19
M3CARBON1
Banned
 
Join Date: Mar 2013
Posts: 300
Reputation: 0 M3CARBON1 is on a distinguished road
Location: London

United Kingdom




Default Re: Fuel Adaptations Explained

I am pretty sure BMW use this to pull back fuel consumption while cruising at part throttle. It makes sense?!
Jump to top M3CARBON1 is offline   Reply With Quote
Old Tue, Oct-15-2013, 02:53:59 PM   #20
geargrndr
Working for Nefarious Porpoises
 
Join Date: Jun 2010
Posts: 836
Reputation: 0 geargrndr is on a distinguished road
Location: AndoverRockport MA & Intl

United States




Default Re: Fuel Adaptations Explained

Quote:
Originally Posted by Donkey1 View Post
Full throttle fuel trim also makes no sense because a normal lambda sensor can't measure lambda values outside the range of 1 (AFR 14.7) and it is not wanted to drive at lambda 1 at full load.

That's why you have a specific full throttle injection map which is used at full throttle because then you have no adaption at all.
That makes complete sense that adaptation gets switched off for WOT, but this table still gives you a selective way to turn off adaptations for part throttle aka mid-loads, and I find that's very beneficial to driving quality, even if its likely at the cost of emissions/mileage.

Because the long-term trims tend to get set at cruise-level loads, and by nature are slow to change, they inherently can be off the mark for sub-WOT loads. That is why there's a noticeable benefit and on many cars (not just our S54) people find a 'performance boost' from clearing adaptations to force the tune back to the base map.
__________________
2003 M3CicM6 TiAg
2002 540iT Sport Vortech S/C 6MT LSD TiAg
2008 Audi A3 2.0T DSG (hers)
1999 Cherokee Sport 4L (trailer-hitched in-law loaner bomber)

Recently Former...
1995.5 Audi S6 Avant (utility/winter billetturbobattlewagen)


Jump to top geargrndr is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT. The time now is 03:16:12 AM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
M3Forum.com and M3forum.net is in no way sponsored, endorsed or affiliated by or with BMW NA / BMW AG or any of it's subsidiaries or vendors.
BMW and M3 (E90 M3 | E92 M3 | E93 M3 | E46 M3 | E36 M3 | E30 M3) are registered trademarks of BMW AG.
M3Forum Terms of Service
Copyright 1999-2017 M3Forum.com
Discussing Fuel Adaptations Explained in the Coding and Tuning Forum - Discuss all avenues of coding and tuning here! at BMW M3 Forum.com (E30 M3 | E36 M3 | E46 M3 | E92 M3 | F80/X)