Ltft's doable need help
Thread Starter
Racer
Joined: Oct 2007
Posts: 332
Likes: 23
Ltft's diablo need help
I was bored last night so I performed a cruise log with my diablo predator. My ltft's are -2.34 and -3.12 . Should I be concerned?
Last edited by netster; Jul 13, 2010 at 10:47 PM.
Supporting Vendor
Joined: Aug 2007
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From: CT
go +1% on the injector slope setting...
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06MonteSS / DiabLew Tune
2014 Camaro 2SS/RS LS3, short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake, catch-can, ported/polished TB, Custom DiabLew Tune
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com
06MonteSS / DiabLew Tune
2014 Camaro 2SS/RS LS3, short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake, catch-can, ported/polished TB, Custom DiabLew Tune
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com
Thread Starter
Racer
Joined: Oct 2007
Posts: 332
Likes: 23
I guess this means I'm running a little rich? So I'll upload the same tune that's in the car now, but adjust the IS before I upload to the car. Does the adjusted IS get saved to the tune that is currently on the predator or would I have to adjust again in the future? I don't know why i'd have to upload it again, just a general question?
Supporting Vendor
Joined: Aug 2007
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From: CT
I guess this means I'm running a little rich? So I'll upload the same tune that's in the car now, but adjust the IS before I upload to the car. Does the adjusted IS get saved to the tune that is currently on the predator or would I have to adjust again in the future? I don't know why i'd have to upload it again, just a general question?
if you change tunes or restore original backup, you will have to make the change again when you reinstall the tune... it does not alter the canned/preset diablo tune that is on the predator...
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Instructor
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From: Lenexa KS
yes. the STFT/LTFT is the percent change in delivered gas that the car has to make to get your AFR to stoich. so, positive means that its adding more gas, so its leaner (before the correction). negative means that its pulling gas, so its richer (before the correction)
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Joined: Aug 2007
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From: CT
when you adjust the slope negative, that tells the ecm that your injectors are smaller and to spray MORE fuel, thus making you richer...
when you adjust the slope positive, it tells the ecm that your injectors are bigger, and to spray LESS fuel, thus making you leaner...
so, negative = richer... positive = leaner
BUT, that's only for the part-throttle fueling / injector slope...
when you adjust the WOT/PE fueling, negative = leaner, and positive = richer
when you adjust the slope positive, it tells the ecm that your injectors are bigger, and to spray LESS fuel, thus making you leaner...
so, negative = richer... positive = leaner
BUT, that's only for the part-throttle fueling / injector slope...
when you adjust the WOT/PE fueling, negative = leaner, and positive = richer
Last edited by 06MonteSS; Jul 14, 2010 at 09:55 AM.
Thread Starter
Racer
Joined: Oct 2007
Posts: 332
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Le Mans Master
Joined: Aug 2005
Posts: 5,375
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From: CA.
St. Jude Donor '13-'14-'15
when you adjust the slope negative, that tells the ecm that your injectors are smaller and to spray MORE fuel, thus making you richer...
when you adjust the slope positive, it tells the ecm that your injectors are bigger, and to spray LESS fuel, thus making you leaner...
so, negative = richer... positive = leaner
BUT, that's only for the part-throttle fueling / injector slope...
when you adjust the WOT/PE fueling, negative = leaner, and positive = richer
when you adjust the slope positive, it tells the ecm that your injectors are bigger, and to spray LESS fuel, thus making you leaner...
so, negative = richer... positive = leaner
BUT, that's only for the part-throttle fueling / injector slope...
when you adjust the WOT/PE fueling, negative = leaner, and positive = richer
"Injector flow rate " If so that table is scaled by manifold vaccum
usually in KPA and in the recipricol where "0" vacuum= 100 KPA or WOT
There is not (in EFILIVE anyway) any refernce to PE or P/T closed loop fueling --smaller IFR #'s should make it leaner--everywhere--- ????
PS: every tuner uses different methods of tuning . I was taught to NEVER mess with the IFR table unless you change injectors---i always make minor LTFT corrctions with the MAF table and WOT corrections with the PE table
Melting Slicks
Joined: Feb 2006
Posts: 2,163
Likes: 5
From: Houston
Not quite sure I understand what you mean-- You guys refer to "Injector slope" not familiar with that term---Do you mean the
"Injector flow rate " If so that table is scaled by manifold vaccum
usually in KPA and in the recipricol where "0" vacuum= 100 KPA or WOT
There is not (in EFILIVE anyway) any refernce to PE or P/T closed loop fueling --smaller IFR #'s should make it leaner--everywhere--- ????
PS: every tuner uses different methods of tuning . I was taught to NEVER mess with the IFR table unless you change injectors---i always make minor LTFT corrctions with the MAF table and WOT corrections with the PE table
"Injector flow rate " If so that table is scaled by manifold vaccum
usually in KPA and in the recipricol where "0" vacuum= 100 KPA or WOT
There is not (in EFILIVE anyway) any refernce to PE or P/T closed loop fueling --smaller IFR #'s should make it leaner--everywhere--- ????
PS: every tuner uses different methods of tuning . I was taught to NEVER mess with the IFR table unless you change injectors---i always make minor LTFT corrctions with the MAF table and WOT corrections with the PE table
Supporting Vendor
Joined: Aug 2007
Posts: 1,453
Likes: 86
From: CT
Not quite sure I understand what you mean-- You guys refer to "Injector slope" not familiar with that term---Do you mean the
"Injector flow rate " If so that table is scaled by manifold vaccum
usually in KPA and in the recipricol where "0" vacuum= 100 KPA or WOT
There is not (in EFILIVE anyway) any refernce to PE or P/T closed loop fueling --smaller IFR #'s should make it leaner--everywhere--- ????
PS: every tuner uses different methods of tuning . I was taught to NEVER mess with the IFR table unless you change injectors---i always make minor LTFT corrctions with the MAF table and WOT corrections with the PE table
"Injector flow rate " If so that table is scaled by manifold vaccum
usually in KPA and in the recipricol where "0" vacuum= 100 KPA or WOT
There is not (in EFILIVE anyway) any refernce to PE or P/T closed loop fueling --smaller IFR #'s should make it leaner--everywhere--- ????
PS: every tuner uses different methods of tuning . I was taught to NEVER mess with the IFR table unless you change injectors---i always make minor LTFT corrctions with the MAF table and WOT corrections with the PE table
using the diablo CMR tuning software, yes, you have access to all the parameters in the tune file, like the MAF table... so it can be done that way using the tuning software if the person gets a custom tune... but there's no way you're going to be able to adjust that table with a handheld device... hahaha... so, they are given the injector slope (flow rate) parameter to adjust... 100% correct way to do it? probably not... but does it work??? yes it does...
Melting Slicks
Joined: May 2008
Posts: 2,606
Likes: 355
From: Rochester New York
Slightly negative or 0 LTFT is GOOD. Any more than 1-2% and I would make some adjustments. Also, negative means its leaning it out. So make sure you know why its leaning it out. A high IAT can cause this. So can coming to an idle after a WOT pull. I think it might be a better idea to adjust your MAF -1% for starters. You might have it set too high. I wouldn't mess with the injector settings if you have stock injectors.
Supporting Vendor
Joined: Aug 2007
Posts: 1,453
Likes: 86
From: CT
Slightly negative or 0 LTFT is GOOD. Any more than 1-2% and I would make some adjustments. Also, negative means its leaning it out. So make sure you know why its leaning it out. A high IAT can cause this. So can coming to an idle after a WOT pull. I think it might be a better idea to adjust your MAF -1% for starters. You might have it set too high. I wouldn't mess with the injector settings if you have stock injectors.
