Target AFR and Actual AFR
#1
Target AFR and Actual AFR
Guys,
I want to flash my ECU and use the xede as a boost controller only. I think I have the target timing exactly as I want it based on my xede adjusted timing.
I want to know if my target Fuel Map numbers will give me the actual AFRs that I want.
Here is the high octane fuel map that I have
And here are the actual AFRs that I want to hit
Would the numbers in the fuel map translate into the actual AFRs that I am currently getting?
What numbers should I put in the Fuel Map to get these actual AFR numbers?
TIA
I want to flash my ECU and use the xede as a boost controller only. I think I have the target timing exactly as I want it based on my xede adjusted timing.
I want to know if my target Fuel Map numbers will give me the actual AFRs that I want.
Here is the high octane fuel map that I have
And here are the actual AFRs that I want to hit
Would the numbers in the fuel map translate into the actual AFRs that I am currently getting?
What numbers should I put in the Fuel Map to get these actual AFR numbers?
TIA
#2
Evolved Member
iTrader: (17)
Hey, you should just get rid of the xede, if your only gonna use it for boost control. Also glad to see your going to a flashed ECU. I think its better then a XEDE (I had one too, if you didnt know)
To your question, IIRC, those number dont always coralate perfectly with the actual AFR. Meaning, there no way for us to tell you what numbers will achive XX.X AFRs.
To your question, IIRC, those number dont always coralate perfectly with the actual AFR. Meaning, there no way for us to tell you what numbers will achive XX.X AFRs.
#3
Evolved Member
iTrader: (18)
nj I could the xede offsets be used as a template ? the xede offsets the ECU fuel map by a % in a cell , if the ECU value is 9.6 and the xede changes it by 9% =10.5 ((9.6 x.09) + 9.6). It would be a very interesting test, it may not correlate directly since the xede does the offset by changing the maf values.
#4
Typically, you would just treat the fuel map numbers as arbitrary numbers, much like the duty cycle numbers in some ECU maps. Then you have three basic 'charts'. You have your actual (what you are logging), you have your desired, and you have the ECU map.
The formula for a cell would then be something like:
newmap = desired / (actual / currentmap)
Look at 2500/90. Desired is 12.8 (12.76). Map is 14.3. Let's assume that when you log you get an actual of 13.9.
12.8 / (13.9 / 14.3) = 13.2
So, if 14.3 in the map gives you 13.9, 13.2 in the map should give you about 12.8.
The problem you have is that you are currently running a piggyback and your ECU table is way lean for your timing, etc. So, to get started you probably either need to adjust the table manually, with a fudge factor on the rich side, or try something like Jorge T suggests. Once you have a rough map, you should be able to fine tune it back to your 'target' (your actual with the piggyback), using the scheme above.
Good Luck,
-jjf
The formula for a cell would then be something like:
newmap = desired / (actual / currentmap)
Look at 2500/90. Desired is 12.8 (12.76). Map is 14.3. Let's assume that when you log you get an actual of 13.9.
12.8 / (13.9 / 14.3) = 13.2
So, if 14.3 in the map gives you 13.9, 13.2 in the map should give you about 12.8.
The problem you have is that you are currently running a piggyback and your ECU table is way lean for your timing, etc. So, to get started you probably either need to adjust the table manually, with a fudge factor on the rich side, or try something like Jorge T suggests. Once you have a rough map, you should be able to fine tune it back to your 'target' (your actual with the piggyback), using the scheme above.
Good Luck,
-jjf
#5
Evolved Member
iTrader: (20)
Join Date: Jul 2005
Location: Tennessee
Posts: 790
Likes: 0
Received 0 Likes
on
0 Posts
Why is ECUFlash better than the Xede? The Xede offers better resolution and also has decimal increments on the timing table for more fine tuning. IMO, the Xede is a good tool to fine tune the stock ECU.
#6
Evolved Member
iTrader: (5)
You will have to load that fuel map and log with a wideband to find out what your actual AFR's will be. There are lots of variables besides your level of modification. Different engines run differently. There is no way to tell exactly what your actual AFR's will be until you run it and log it. AFR targets are arbitrary numbers and just targets. You will probably have to make some minor adjustments here and there if you've never run that fuel map but it doesnt look too far off although I dont really know what a VIII fuel map should look like. For a IX it would be a little lean at spool 3000 rpms load 160-260. Since VIII's spool a little later it may be just right.
#7
You will have to load that fuel map and log with a wideband to find out what your actual AFR's will be. There are lots of variables besides your level of modification. Different engines run differently. There is no way to tell exactly what your actual AFR's will be until you run it and log it. AFR targets are arbitrary numbers and just targets.
For example, if you change the Target AFR by 0.2, what will the Actual AFR change by?
With the Xede for example, a 4% offset on the fuel map will move your AFR by a factor of 1. It is NOT a hard and fast rule, but a general guideline.
I am not asking for 100% accuracy here, but a GENERAL rule would do. I am just surprized that there is no such rule.
Trending Topics
#10
Evolved Member
iTrader: (17)
You right, one of the best features the Xede has over the ECU is the fact you can do decimal increment of timing. Besides that, I find the ECU to be better in everyway.
Also, in this situtation, where NJ is using the Xede for just boost control, it would seem like a better idea to ditch it and get a MBC, EBC or use ECU controlled boost control.
BTW, did you know Vishnu has made a replacement for the Xede. I dont know if theres been word here, but on the BMW forums, Shiv started using the Xede to tune 335i's, but has since made a new computer called the Proccede (basically an updated Xede with more features and opitions) to use on the 335i's. I believe Vishnu's business relationship with Chip Torque is over, but dont quote me.
#11
Evolved Member
iTrader: (18)
In reality it's like this https://www.evolutionm.net/forums/sh...d.php?t=250353 and for the 8 it is perfectly fine and will still be supported.
#13
Evolved Member
iTrader: (30)
No lean spool active, I have found that you can add about 1.44 to the value and be fairly close to WB AFR. If anything its a little low. Almost always its a direct correlation in change to effect. I havent noticed any big shifts (as in .5=1 or .75=1.5) and the small correction factors make this rule work for me. I used both a PLX and a NGK and was similar in my readings.
#14
Evolving Member
iTrader: (1)
Join Date: Sep 2004
Location: Abu Dhabi, UAE
Posts: 119
Likes: 0
Received 0 Likes
on
0 Posts
nj1266
i can see that you are using a screen shot from LogWorks2 software. x-axis is rpm and y axis is LOAD (i think this calculated load)
how can you calculate the load and use it as y-axis using LogWorks2?
i tried but i couldnt find? i searched but no luck
i can see that you are using a screen shot from LogWorks2 software. x-axis is rpm and y axis is LOAD (i think this calculated load)
how can you calculate the load and use it as y-axis using LogWorks2?
i tried but i couldnt find? i searched but no luck
#15
2. Use Tools/Calc to calculate the Load Trace (I've posted the calcs, but I can't remember if it was here or our support forum)
3. Use the calculated trace like any other when you create a new chart.
-jjf