question about positive LTRIMS at WOT
question about positive LTRIMS at WOT My Ltrims are averging around 1.5+ on a 20 minute drive, but at WOT they are 4.7+ and 5.5+. does this mean they are adding that much more fuel @ WOT? and if so, does that effect the 02 reading in anyway?
should i adjust my Ltrims going off of the 1.5+ on regular driving or should i lean it out about 6% becuz its about 5+ at wot?
the reason i ask this is becuz ive read alot of stuff lately about ltrims at wot
thanks
should i adjust my Ltrims going off of the 1.5+ on regular driving or should i lean it out about 6% becuz its about 5+ at wot?
the reason i ask this is becuz ive read alot of stuff lately about ltrims at wot
thanks
On The Tree
Joined: Aug 2002
Posts: 149
Likes: 0
From: NorCal
Re: question about positive LTRIMS at WOT positive(+) numbers mean you are running lean. I don't know that much about tuning, but I know you don't want to be running lean. Hope someone else can help you with the tuning part.
TECH Apprentice
Joined: Dec 2001
Posts: 351
Likes: 0
From: CA
Re: question about positive LTRIMS at WOT </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by WicketMike:
<strong>My Ltrims are averging around 1.5+ on a 20 minute drive, but at WOT they are 4.7+ and 5.5+. does this mean they are adding that much more fuel @ WOT? and if so, does that effect the 02 reading in anyway?
should i adjust my Ltrims going off of the 1.5+ on regular driving or should i lean it out about 6% becuz its about 5+ at wot?
the reason i ask this is becuz ive read alot of stuff lately about ltrims at wot
thanks</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Most people find tuning with the LTFT positive is a pain in the ***, for the same reasons you're talking about. That's why people usually get them to be slightly negative.
Anyway, your O2 readings will reflect the +4.7 and +5.x, so if you're running okay with those, then you don't really have to worry about it.
<strong>My Ltrims are averging around 1.5+ on a 20 minute drive, but at WOT they are 4.7+ and 5.5+. does this mean they are adding that much more fuel @ WOT? and if so, does that effect the 02 reading in anyway?
should i adjust my Ltrims going off of the 1.5+ on regular driving or should i lean it out about 6% becuz its about 5+ at wot?
the reason i ask this is becuz ive read alot of stuff lately about ltrims at wot
thanks</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Most people find tuning with the LTFT positive is a pain in the ***, for the same reasons you're talking about. That's why people usually get them to be slightly negative.
Anyway, your O2 readings will reflect the +4.7 and +5.x, so if you're running okay with those, then you don't really have to worry about it.
TECH Addict
Joined: Dec 2001
Posts: 2,850
Likes: 0
From: Plainville,MA
Re: question about positive LTRIMS at WOT Reading this helped me a lot ! <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
http://www.c5forum.com/diy/ltft.php
<small>[ September 09, 2002, 05:02 AM: Message edited by: Orange Krush ]</small>
http://www.c5forum.com/diy/ltft.php
<small>[ September 09, 2002, 05:02 AM: Message edited by: Orange Krush ]</small>
Re: question about positive LTRIMS at WOT my avg. ltrims where at about 3+ so i leaned it out 5%, now they avg. about 1.5-.. so that looks good, but my ltrims are still positive at WOT, shouldnt they be 0 @ WOT ?
at WOT my ltrims now are about 3+
at WOT my ltrims now are about 3+
TECH Apprentice
Joined: Mar 2002
Posts: 357
Likes: 0
From: Newfoundland, Canada
Re: question about positive LTRIMS at WOT If your ltrims are "positive" it means you're already running lean so if you "leaned it out another 5%", you were only making it worse. With ltrims averaging around +3 like you said, try richening it by 5% and check it again. Should land you on the slighty negative side with ltrims.
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Re: question about positive LTRIMS at WOT Your car is not running rich or lean as long as your Lterms are properly controlling. Your Lterms just mean that your car is percieving a slightly rich or lean condition, and is correcting accordingly. If your Lterms start to get either greater than +25% or less than -25%, then you have a problem, and the car is running so rich or lean that the computer cannot properly compensate. You will set an SES light
AS LONG AS YOU SEE LTERM VALUES WITHIN THESE RANGES, YOU ARE NOT DAMAGING YOUR CAR <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" /> because you are still maintaining the target a/f ratio of 14.8% Too many poeople get concerned with trying to dial in their LTerms to exactly 0.
The way LTerms contribute to WOT is that positive LTerms are added to the current Power Enrichment at WOT. This makes it a total pain in the **** to tune WOT because depending on what the Lterms were when the car went WOT your WOT a/f ratio will be altered accordingly. If the Lterms are negative when the car goes WOT, then the Lterms are dismissed.
And the clencher... Unless you are running without cats with the cat overtemperature protection off, then IMO you are wasteing your time. As long as your CAT overtemperature protection is in (which you need if you have cats), your car is going to get tanked to a low 11 a/f ratio anyways at WOT to protect your cats, so getting your Lterms to slightly negative won't make a difference anyways.
Just make sure your Lterms are within +/- 10% and call it a day. (Until you pull the cats)
AS LONG AS YOU SEE LTERM VALUES WITHIN THESE RANGES, YOU ARE NOT DAMAGING YOUR CAR <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" /> because you are still maintaining the target a/f ratio of 14.8% Too many poeople get concerned with trying to dial in their LTerms to exactly 0.
The way LTerms contribute to WOT is that positive LTerms are added to the current Power Enrichment at WOT. This makes it a total pain in the **** to tune WOT because depending on what the Lterms were when the car went WOT your WOT a/f ratio will be altered accordingly. If the Lterms are negative when the car goes WOT, then the Lterms are dismissed.
And the clencher... Unless you are running without cats with the cat overtemperature protection off, then IMO you are wasteing your time. As long as your CAT overtemperature protection is in (which you need if you have cats), your car is going to get tanked to a low 11 a/f ratio anyways at WOT to protect your cats, so getting your Lterms to slightly negative won't make a difference anyways.
Just make sure your Lterms are within +/- 10% and call it a day. (Until you pull the cats)
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Verdad Gallardo TECH Apprentice
Joined: Mar 2002
Posts: 357
Likes: 0
From: Newfoundland, Canada
Re: question about positive LTRIMS at WOT </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by NoGo:
<strong>The way LTerms contribute to WOT is that positive LTerms are added to the current Power Enrichment at WOT. This makes it a total pain in the **** to tune WOT because depending on what the Lterms were when the car went WOT your WOT a/f ratio will be altered accordingly. If the Lterms are negative when the car goes WOT, then the Lterms are dismissed.
And the clencher... Unless you are running without cats with the cat overtemperature protection off, then IMO you are wasteing your time. As long as your CAT overtemperature protection is in (which you need if you have cats), your car is going to get tanked to a low 11 a/f ratio anyways at WOT to protect your cats, so getting your Lterms to slightly negative won't make a difference anyways.
Just make sure your Lterms are within +/- 10% and call it a day. (Until you pull the cats)</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thanks! Haven't heard it put quite that succinctly before! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
<strong>The way LTerms contribute to WOT is that positive LTerms are added to the current Power Enrichment at WOT. This makes it a total pain in the **** to tune WOT because depending on what the Lterms were when the car went WOT your WOT a/f ratio will be altered accordingly. If the Lterms are negative when the car goes WOT, then the Lterms are dismissed.
And the clencher... Unless you are running without cats with the cat overtemperature protection off, then IMO you are wasteing your time. As long as your CAT overtemperature protection is in (which you need if you have cats), your car is going to get tanked to a low 11 a/f ratio anyways at WOT to protect your cats, so getting your Lterms to slightly negative won't make a difference anyways.
Just make sure your Lterms are within +/- 10% and call it a day. (Until you pull the cats)</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thanks! Haven't heard it put quite that succinctly before! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Teching In
Joined: Sep 2002
Posts: 38
Likes: 0
From: Jensen Beach, FL
Re: question about positive LTRIMS at WOT </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by WicketMike:
<strong>My Ltrims are averging around 1.5+ on a 20 minute drive, but at WOT they are 4.7+ and 5.5+. does this mean they are adding that much more fuel @ WOT? and if so, does that effect the 02 reading in anyway?
should i adjust my Ltrims going off of the 1.5+ on regular driving or should i lean it out about 6% becuz its about 5+ at wot?
the reason i ask this is becuz ive read alot of stuff lately about ltrims at wot
thanks</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Dude, go one more click positive on your MAFT BASE. This will add more fuel and force your fuel trims to back off. It should put you into the negative trims. For some reason the engine always runs better when pulling fuel than adding it. When doing this Keep your WOT set at 0 till your BASE trims stabilize (10 or 20 miles) Then run a new tap and see where wot needs to be. You may not even need to add any more at that point.
I used to run +5BASE and +6 on WOT I had positive fuel trims and no knock but the motor did not feel "SPUNKY"
I since changed to +10 on base and 0 on WOT, now I get a negative fuel trim and very little (1 or 2 degrees) K/R on WOT. The motor is very spunky now. I may just pop the WOT one click...
<strong>My Ltrims are averging around 1.5+ on a 20 minute drive, but at WOT they are 4.7+ and 5.5+. does this mean they are adding that much more fuel @ WOT? and if so, does that effect the 02 reading in anyway?
should i adjust my Ltrims going off of the 1.5+ on regular driving or should i lean it out about 6% becuz its about 5+ at wot?
the reason i ask this is becuz ive read alot of stuff lately about ltrims at wot
thanks</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Dude, go one more click positive on your MAFT BASE. This will add more fuel and force your fuel trims to back off. It should put you into the negative trims. For some reason the engine always runs better when pulling fuel than adding it. When doing this Keep your WOT set at 0 till your BASE trims stabilize (10 or 20 miles) Then run a new tap and see where wot needs to be. You may not even need to add any more at that point.
I used to run +5BASE and +6 on WOT I had positive fuel trims and no knock but the motor did not feel "SPUNKY"
I since changed to +10 on base and 0 on WOT, now I get a negative fuel trim and very little (1 or 2 degrees) K/R on WOT. The motor is very spunky now. I may just pop the WOT one click...
Re: question about positive LTRIMS at WOT i dont have MAFT anymore, i have ls1edit,
i have it set at 8% more right now on base, and im getting .8 ltrims at WOT, so i got it down alot,im going to try 9% and 10% to see if that will take care of it.
let you know if it works
i have it set at 8% more right now on base, and im getting .8 ltrims at WOT, so i got it down alot,im going to try 9% and 10% to see if that will take care of it.
let you know if it works
Teching In
Joined: Sep 2002
Posts: 38
Likes: 0
From: Jensen Beach, FL
Re: question about positive LTRIMS at WOT </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by WicketMike:
<strong>i dont have MAFT anymore, i have ls1edit,
i have it set at 8% more right now on base, and im getting .8 ltrims at WOT, so i got it down alot,im going to try 9% and 10% to see if that will take care of it.
let you know if it works</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yeah, that's he nice thing about LS1-EDIT... The granularity down to 1%. The MAFT was 5% every time... <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />
I should have my LS1-Edit in a week or 2... I can't wait... Goodbye MAFT
<strong>i dont have MAFT anymore, i have ls1edit,
i have it set at 8% more right now on base, and im getting .8 ltrims at WOT, so i got it down alot,im going to try 9% and 10% to see if that will take care of it.
let you know if it works</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yeah, that's he nice thing about LS1-EDIT... The granularity down to 1%. The MAFT was 5% every time... <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />
I should have my LS1-Edit in a week or 2... I can't wait... Goodbye MAFT
Re: question about positive LTRIMS at WOT I am a bit confused about this cat thing and wot..I can dial my car down with my maft and the o2s stay down..I can change my air fuel as evidence by increasing knock when I got leaner and car feels different at different settings and gets slower too rich..I have seen lots of dyno graphs with cars at 13.1 wide open and some of those have cats..so how can the cars be running at like 11.7??? Makes no sense..anyone else know something about this....are you telling me my cats will die running in the ideal 12.8 to 13.2 range..?? I had my car leaned down for many thousand miles before with my maft and stock cats with no problems....
Teching In
Joined: Sep 2002
Posts: 38
Likes: 0
From: Jensen Beach, FL
Re: question about positive LTRIMS at WOT </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by MY99TAWS6:
<strong>I am a bit confused about this cat thing and wot..I can dial my car down with my maft and the o2s stay down..I can change my air fuel as evidence by increasing knock when I got leaner and car feels different at different settings and gets slower too rich..I have seen lots of dyno graphs with cars at 13.1 wide open and some of those have cats..so how can the cars be running at like 11.7??? Makes no sense..anyone else know something about this....are you telling me my cats will die running in the ideal 12.8 to 13.2 range..?? I had my car leaned down for many thousand miles before with my maft and stock cats with no problems....</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have gutted cats and O2 simms <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> So I dont have that problem. But once I get my LS1-Edit it's COTS disabled for me..
I wish I knew exactly how dangerous it is to let the CATS get hot...If it just wrecks the CAT who cares. I just don't want a fire under the tunnel <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />
<strong>I am a bit confused about this cat thing and wot..I can dial my car down with my maft and the o2s stay down..I can change my air fuel as evidence by increasing knock when I got leaner and car feels different at different settings and gets slower too rich..I have seen lots of dyno graphs with cars at 13.1 wide open and some of those have cats..so how can the cars be running at like 11.7??? Makes no sense..anyone else know something about this....are you telling me my cats will die running in the ideal 12.8 to 13.2 range..?? I had my car leaned down for many thousand miles before with my maft and stock cats with no problems....</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have gutted cats and O2 simms <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> So I dont have that problem. But once I get my LS1-Edit it's COTS disabled for me..
I wish I knew exactly how dangerous it is to let the CATS get hot...If it just wrecks the CAT who cares. I just don't want a fire under the tunnel <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />
