How to tune LTrims using LS1 Edit ???
Thread Starter
Joined: Nov 2001
Posts: 10,060
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From: Canton, GA
How to tune LTrims using LS1 Edit ??? Did a long cruise in the car and logged the LTrims. I have the SLP MAF with stock LS1 tuning. LTrims averaged out to about 10.7 through the cruise (a little lean).
What do I do in LS1 Edit to richen the LTrims up? Need to get these to a nice level before I finalize my A/F adjustments for WOT. Right now, I am pulling fuel in ther PE vs. RPM table, and I'm still a little rich.
I asked this on LS! Edit email list, but haven't gotten any answers <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />
What do I do in LS1 Edit to richen the LTrims up? Need to get these to a nice level before I finalize my A/F adjustments for WOT. Right now, I am pulling fuel in ther PE vs. RPM table, and I'm still a little rich.
I asked this on LS! Edit email list, but haven't gotten any answers <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />
Teching In
Joined: Jan 2002
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From: NJ
Re: How to tune LTrims using LS1 Edit ??? Reckless,
You don't say what other mods you have. If the injectors are stock, why would you change the Injevtor tables. What you say you swapped out was the MAF, so I would start to trim it with the MAF table.
KenK
You don't say what other mods you have. If the injectors are stock, why would you change the Injevtor tables. What you say you swapped out was the MAF, so I would start to trim it with the MAF table.
KenK
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From: College Station, Tx
Re: How to tune LTrims using LS1 Edit ??? I would shoot for -4 to -5 on the l-trims - you can adjust the timing to whatever you desire, so that shouldn't be a consideration (with ls1 edit).
To tune at part throttle (adjusting l-trims) your best bet is to tweak the MAF transfer function.
Log your runs, import the file into excel and make a little chart that plots afgs as a function of frequency (maf) and l-trims. You might try a pivot table, etc. Now find the points where your l-trims are, and scale those airflow values at that frequency by the percent change you need.
Program, autotap, and repeat as needed.
Chris
To tune at part throttle (adjusting l-trims) your best bet is to tweak the MAF transfer function.
Log your runs, import the file into excel and make a little chart that plots afgs as a function of frequency (maf) and l-trims. You might try a pivot table, etc. Now find the points where your l-trims are, and scale those airflow values at that frequency by the percent change you need.
Program, autotap, and repeat as needed.
Chris
Thread Starter
Joined: Nov 2001
Posts: 10,060
Likes: 33
From: Canton, GA
Re: How to tune LTrims using LS1 Edit ??? OK. My fuel system is the farthest thing from stock:
Weldon 2025 pump
-8AN line to front into two -6AN lines (one for each rail)
SVO 42lb injectors
Paxton Regulator on the rails
I set up the injector flow using the injector scaling file Chris provided (MS Excel). I played and played with the PE vs. RPM yesterday, and it took forever to bring the WOT O2s down.
So today, I stumble across an old post talking about LTrims and how to richen in the "MAF" table. I tried that out. GAWD! Worked very well to richen the LTrims at cruise. I was right around -2 cruising and -2 to 0 at idle <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Time for a WOT autotap run! Yikes! O2s dropped like a freakin lead balloon! I guess now that I have the MAF tuned in, I've got to go back to the drawing board on the PE vs. RPM tables. I had most of the table set to -1.5 to pull some fuel out. I reset them all to zero across the board and will allow time for driving adjustment. I will do another Autotap at WOT tomorrow and see what I get.
Funny thing, as lean as it was, I still saw NO KR! My KR was desensitized some by Ed, but I need to learn that next. Damn I have a lot to learn <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
Todd
Weldon 2025 pump
-8AN line to front into two -6AN lines (one for each rail)
SVO 42lb injectors
Paxton Regulator on the rails
I set up the injector flow using the injector scaling file Chris provided (MS Excel). I played and played with the PE vs. RPM yesterday, and it took forever to bring the WOT O2s down.
So today, I stumble across an old post talking about LTrims and how to richen in the "MAF" table. I tried that out. GAWD! Worked very well to richen the LTrims at cruise. I was right around -2 cruising and -2 to 0 at idle <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Time for a WOT autotap run! Yikes! O2s dropped like a freakin lead balloon! I guess now that I have the MAF tuned in, I've got to go back to the drawing board on the PE vs. RPM tables. I had most of the table set to -1.5 to pull some fuel out. I reset them all to zero across the board and will allow time for driving adjustment. I will do another Autotap at WOT tomorrow and see what I get.
Funny thing, as lean as it was, I still saw NO KR! My KR was desensitized some by Ed, but I need to learn that next. Damn I have a lot to learn <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
Todd
Trending Topics
Re: How to tune LTrims using LS1 Edit ??? Reckless,
Do a search on this matter.
If you swapped out the MAF, then you should modify the MAF table with LS1Edit. Thats what I did and got my Ltrims from +15% to +20% down to 0% to -3%.
Do a search on this matter.
If you swapped out the MAF, then you should modify the MAF table with LS1Edit. Thats what I did and got my Ltrims from +15% to +20% down to 0% to -3%.
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Verdad Gallardo Thread Starter
Joined: Nov 2001
Posts: 10,060
Likes: 33
From: Canton, GA
Re: How to tune LTrims using LS1 Edit ??? Thanks everyone so far. The trick to tuning the MAF in the "MAF" table is:
Higher numbers = richer LTrims
Lower Number = leaner LTrims
So if you are lean due to a MAF swap, highlight from 1500-600Hz and multiply all these cells by 120%.
After that, multiply one cell at a time (moving right) by the next lower value (i.e., 119%, 118%, 117%, etc.). This will net about a 15% change overall in the MAF. So if you are at +10 - +15 on your LTrims, use this. If you are on the rich side for LTrims, do the opposite.
OBTW....you can stop multiplying when you get to 100% <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Don't think "exact" numbers are imnportant, you just want to richen or lean across the board evenly.
This info was provided in an earlier post by Doc99SShome here: https://ls1tech.com/ubb/cgi-bin/ulti...;f=23;t=000205
Todd
<small>[ March 18, 2002, 11:51 AM: Message edited by: Reckless ]</small>
Higher numbers = richer LTrims
Lower Number = leaner LTrims
So if you are lean due to a MAF swap, highlight from 1500-600Hz and multiply all these cells by 120%.
After that, multiply one cell at a time (moving right) by the next lower value (i.e., 119%, 118%, 117%, etc.). This will net about a 15% change overall in the MAF. So if you are at +10 - +15 on your LTrims, use this. If you are on the rich side for LTrims, do the opposite.
OBTW....you can stop multiplying when you get to 100% <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Don't think "exact" numbers are imnportant, you just want to richen or lean across the board evenly.
This info was provided in an earlier post by Doc99SShome here: https://ls1tech.com/ubb/cgi-bin/ulti...;f=23;t=000205
Todd
<small>[ March 18, 2002, 11:51 AM: Message edited by: Reckless ]</small>
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Joined: Feb 2002
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From: the moon
Re: How to tune LTrims using LS1 Edit ??? you can change a-tap parameters to either show standard or metric.
Windows a-tap will do both at the same time.
simple math to convert though.
either x or / by 7.56 to switch back and forth between g/sec or lb/min <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
Steve
Windows a-tap will do both at the same time.
simple math to convert though.
either x or / by 7.56 to switch back and forth between g/sec or lb/min <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
Steve
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From: College Station, Tx
Re: How to tune LTrims using LS1 Edit ??? I really wouldn't just select an arbitrary selection and multiply by a percent. Seriously, use Excel <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> .
1) Log your MAF and L-trims and Raw MAF Hz with autotap.
2) Export to a CSV file
3) Open/import the file into excel.
4) Make a new column with your left and right l-trims averaged (if you have a large split at anywhere but idle address that first)
5) Make a Pivot table that plots your Hz on the X-axis and your MAF airflow on the right axis with L-trims populating the table.
6) Find the correction factor you need to bring your l-trims down to -2 to -4, apply those factors to the MAF AFGS values, then display the results as a new table (Hz with the new corrected MAF airflow).
If you are just off by a factor across the board then you can try scaling your MAF table by a percentage across the board.
Chris
1) Log your MAF and L-trims and Raw MAF Hz with autotap.
2) Export to a CSV file
3) Open/import the file into excel.
4) Make a new column with your left and right l-trims averaged (if you have a large split at anywhere but idle address that first)
5) Make a Pivot table that plots your Hz on the X-axis and your MAF airflow on the right axis with L-trims populating the table.
6) Find the correction factor you need to bring your l-trims down to -2 to -4, apply those factors to the MAF AFGS values, then display the results as a new table (Hz with the new corrected MAF airflow).
If you are just off by a factor across the board then you can try scaling your MAF table by a percentage across the board.
Chris
Thread Starter
Joined: Nov 2001
Posts: 10,060
Likes: 33
From: Canton, GA
Re: How to tune LTrims using LS1 Edit ??? HAHA Chris! You crack me up! You must be one hella Excel geek! I thought I knew Excel pretty well, but you lost me at about step 4. How about I reset the MAF readings to stock, then ATAP, and then email you the file? <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Todd
Todd
Re: How to tune LTrims using LS1 Edit ??? ChrisB, excellent idea!
I just want to point out that ATAP records the MAF flow rate in Lbm/min, while the MAF table in LS1Edit is in units of: gms/sec
conversion: ATAP value * 453.6/60 = MAF table
I believe that this is the correct conversion. Can anyone confirm this?
I take my ATAP log files over into Excel and insert a new column next to the column containing my MAF flow rate values. Then I create a formula that converts the MAF flow rate from lbm/min to gm/sec. (FWIW)
I just want to point out that ATAP records the MAF flow rate in Lbm/min, while the MAF table in LS1Edit is in units of: gms/sec
conversion: ATAP value * 453.6/60 = MAF table
I believe that this is the correct conversion. Can anyone confirm this?
I take my ATAP log files over into Excel and insert a new column next to the column containing my MAF flow rate values. Then I create a formula that converts the MAF flow rate from lbm/min to gm/sec. (FWIW)
Oz Director
Joined: Nov 2001
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From: Australia
Re: How to tune LTrims using LS1 Edit ??? ChrisB
Very interesting topic, i was hoping someone to finish it, as i can host the tables if you need someone to.
If don't mine can you sent me the excel file to andrew@holdenls1.com
Thank's.
Very interesting topic, i was hoping someone to finish it, as i can host the tables if you need someone to.
If don't mine can you sent me the excel file to andrew@holdenls1.com
Thank's.
Re: How to tune LTrims using LS1 Edit ??? Chris, we NEED that sheet <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> Please please <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
TECH Addict
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From: College Station, Tx
Re: How to tune LTrims using LS1 Edit ??? Whoops - not in town right now, but when I get back I will work one up.
It's not really a ready made spreadsheet per-se - I just do it on the fly when I need it.
If someone wants to mail me a log file to look at with pertinent data I will do one based on that.
Give me at least 15 or so minutes of logging, export it as a CSV. I need MAF (g/sec) as well as "RAW MAF INPUT FREQUENCY" (Hz). L-trim data as well.
Chris
It's not really a ready made spreadsheet per-se - I just do it on the fly when I need it.
If someone wants to mail me a log file to look at with pertinent data I will do one based on that.
Give me at least 15 or so minutes of logging, export it as a CSV. I need MAF (g/sec) as well as "RAW MAF INPUT FREQUENCY" (Hz). L-trim data as well.
Chris
Re: How to tune LTrims using LS1 Edit ??? Chris, I'd pay your for a spreadsheet so that what I imported my .csv file it be tabulated and I could see where to adjust my MAF flow based on the plot. Tuning part throttle LTRIMs is the cornerstone to having a properly tuned vehicle, IMO.
Also, when you said above to average the LTRIMs into a column did you mean to avg both banks LTRIMs into one column? Thanks.
<small>[ May 07, 2002, 08:10 PM: Message edited by: NastyC5 ]</small>
Also, when you said above to average the LTRIMs into a column did you mean to avg both banks LTRIMs into one column? Thanks.
<small>[ May 07, 2002, 08:10 PM: Message edited by: NastyC5 ]</small>