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ltft?

jim97regalgs

jim97regalgs

New member
just wondering what everyone's ltfts look like. especially at idle and cruise. mine at wot is anywhere from -2 to -4 and in cruise it mostly at -10, idle goes from 0 to -12s. oh my car is a 97 regal gs btw. using hpt.
 


thanks guys. 01gpgt01 that is the thread we been using to tune my car but we only did the histogram scanning part once. theses numbers i posted were after 3 days of driving since the tune. the tune was pretty locked in the day we tuned it but after a few days of driving the numbers have changed.is that normal? i will redo it a few more times and try to get the ltft locked in at zero at wot and as close to zero as i can at cruise like u said.
 


It would be a good idea to retune, when you do you won't get everything to 0%. As long as the values are between -5% and 5% then you're doing good. I borrowed the tuner I used but I know from watching my WB that I've got some tweaking to do when I though I was done.
 
Remember that your "tune" is no better or worse if you have less trims...

if you have a fueling of lets say 10, and a LTFT of -2, you have an actual fueling of 8... You come through and "tune" your fuel to 8, now you have a LTFT of 0, and an actual fueling of 8.
 
darkhorizon said:
Remember that your "tune" is no better or worse if you have less trims...

if you have a fueling of lets say 10, and a LTFT of -2, you have an actual fueling of 8... You come through and "tune" your fuel to 8, now you have a LTFT of 0, and an actual fueling of 8.
Click to expand...

lost me on that one lol.
 
darkhorizon said:
Remember that your "tune" is no better or worse if you have less trims...

if you have a fueling of lets say 10, and a LTFT of -2, you have an actual fueling of 8... You come through and "tune" your fuel to 8, now you have a LTFT of 0, and an actual fueling of 8.
Click to expand...

true for part throttle... but at WOT if your trims are locking in wrong you are just setting up for KR. if the trims are Neg as it gets into WOT it will stay Neg and if you need more fuel the car wont be giving it. you go lean and hopefully not BOOM.

best thing for people to do when learning to tune is... make small changes, and read and reread and rerereread jerrys tune notebook. and don't make any changes in the bin unless you know why it needs changed and know how to verify the change worked. flipping switches just to see what happens doesn't always have favorable results.
 


well turns out i need to tune it better. my tune keeps changing for some odd reason. every time we tune it my afrs and ltft change with in a week or more of normal driving. i dont know if we are doing thing wrong or what. but we tune it and get the ltft locked in and afr in the mid 11s then after a week or so my ltft are whack high and my afr always settle to 12.2s max. when this happens i sometimes get kr. anyone have any idea? we are using this thread for tuning= http://www.grandprixforums.net/starting-hptuners-43997.html
 
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