LTFT's
LTFT's
I'm having some slight KR issues on my LS1 GTO. I had to pull some timing to kill KR and I still have some at mid throttle, then I looked at my Long Terms. I started at 7.03% at cruise, adjusted slope to -8% and WOT fuel to -7% and ended up with -.78%. Part throttle KR dropped to .43 fairly regularly. Would adding another 1% to WOT fuel be a good decision at this point? I don't want to pull more timing as I'm at -10%, which works out to 2 degrees pulled at WOT throttle before heatsoak starts robbing me.
RE: LTFT
sure, you can do that... won't hurt anything...
you're probably getting the KR at WOT because you took out too much fuel in the PE settings and are now too lean...
what I do is, I get my slope adjusted to get my ltft's at -1, and then leave my PE settings alone at the default 0 settings... and this gives me an AFR at WOT of 12.6 to 12.8....
get your ltft's dialed in, put the PE fueling settings back to the default settings of 0, and put your timing back to where it was originally.
then do another run and let's see what'cha got
also, what tune are you using, and what gas? what brand?? you want to use good fuel such as Mobil, Exxon, Sunoco, Amoco or BP... bad fuel will cause KR issues as well... I used to have a ton of KR when I used to use Shell gas... after switching over to Mobil 93 octane, the bad KR issues went away...
you're probably getting the KR at WOT because you took out too much fuel in the PE settings and are now too lean...
what I do is, I get my slope adjusted to get my ltft's at -1, and then leave my PE settings alone at the default 0 settings... and this gives me an AFR at WOT of 12.6 to 12.8....
get your ltft's dialed in, put the PE fueling settings back to the default settings of 0, and put your timing back to where it was originally.
then do another run and let's see what'cha got
also, what tune are you using, and what gas? what brand?? you want to use good fuel such as Mobil, Exxon, Sunoco, Amoco or BP... bad fuel will cause KR issues as well... I used to have a ton of KR when I used to use Shell gas... after switching over to Mobil 93 octane, the bad KR issues went away...
06MonteSS / DiabLew Tune
2014 Camaro SS - 2SS, RS pkg., short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com -- www.diablocustomtuning.net
2014 Camaro SS - 2SS, RS pkg., short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com -- www.diablocustomtuning.net
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sickREDsierra
- Posts: 979
- Joined: Thu Nov 01, 2007 1:06 pm
RE: LTFT
he was listening to jsk06c6's suggestions, i would think.
i agree with Lew....tuning IMO should be done one setting at a time. get your LTFT's dialed in, double check them, then monitor at WOT for your A/FR and KR. make adjustments from there. if you change a lot of stuff at once, its hard to tell where the real adjustment was made, and it affects every other parameter.
i agree with Lew....tuning IMO should be done one setting at a time. get your LTFT's dialed in, double check them, then monitor at WOT for your A/FR and KR. make adjustments from there. if you change a lot of stuff at once, its hard to tell where the real adjustment was made, and it affects every other parameter.
2007 Sierra, 370 C.I. , Custom CompCam, ProEdge 3600 converter, 4.11's with eaton LSD, Foose 20's, DynoTune Nitrous, Patriot CNC'd heads
RE: LTFT
I zeroed out my PE settings and took it for a drive, still getting very light KR under heavy throttle. I took the slope setting from -8 to -9 and it disappeared, so I bumped my timing back to 0 advance/retard and no KR at all. I probably could advance timing a bit with my settings, but I'm thinking that's a bit ambitious on 91 octane on the Performance/Diablo tune. It worked well, but I'll have to keep an eye on it when the climate changes as our gas isn't as good during the summer. I wish we had better than 91 though.
I'm sitting right at -.78/-1.56 at cruise. I think I finally got it dialed in just right.
I'm sitting right at -.78/-1.56 at cruise. I think I finally got it dialed in just right.
RE: LTFT
aaaah, yeah... the Diablo tune is really made for good 93 octane gas, as it has more advanced timing in it already compared to the 91 tune...
nice LTFT numbers man! sounds/looks like ya got it!!
how's the car feel now???
nice LTFT numbers man! sounds/looks like ya got it!!
how's the car feel now???
06MonteSS / DiabLew Tune
2014 Camaro SS - 2SS, RS pkg., short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com -- www.diablocustomtuning.net
2014 Camaro SS - 2SS, RS pkg., short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com -- www.diablocustomtuning.net
RE: LTFT
It feels strong, from about 10-15mph it lit the tires straight up and started going sideways. I can't believe I'm not getting KR with 91 octane. I thought my problem was crap gas, but it was all in a tune. My fuel mileage increased as well, I think the car was dumping too much gas trying to overcompensate at cruise.