high load low rpm bog

[4.8t]

ok i have this horrable low rpm high load bog that is driving me up the wall. i can't get it and its not timming i change it alot and didn't help but i pulled some full and it help some but i'm afraid to pull to much any clue's ???

[S2H]

tuning with LTFT or wideband??
with a wideband you can just shoot for 14.63 using afr error....or when you kick into PE use whatever value its commanding
also depends on what gear you are in
6th gear will always feel liek a turd at low rpm...nature of the beast...
just remember how little torque you have down low when grogging along

[jimmyblue]

You don't want to be at low RPM with high load.
That's the bottom line. Try adjusting the A4 shift
profile to put you in the powerband and you can
maybe quit worrying about the "bog". A better
torque converter will also make up for some of
this.

But I'd have a look at delivered spark advance
relative to what your high octane table asks for,
by way of seeing whether this truck has the same
lousy burst knock action I've seen on earlier 5.3s;
look at the PE enrichment rate and mode delay
to see if you're being held lean and getting knock
retard on account of it. Maybe you are in fact
over-enriched at high MAP, low RPM (or all RPM),
decide whether your open loop fuel air table is
excessively fat, or your PE table.

But powerband management will put you to a
happier place.

[4.8t]

ok i updated the signature so all know what i got to better help. well this bog also affects me becouse it hit this load on hard launch. some times down in the 1.12 and 1.20 on the spark and 95 and 100 kpa on the ltft all at 1200-1600 rpm but i think i found the fat side of things and i leaned it up some. i remimber fattening it up in this area to get rid of nock but did not work and when i retarded the timming i forgot to lean it back out. i'm running an 05 cts-v retard tables becouse i installed the 5.7 and took out the iron block so i figured i would get kr tables for something a little closer to what i have and i figured 05 tables would be the latest and greatest so i used these. but i seem to get alot of kr at load but at wot its good until about 90-100 i start getting kr again and it sucks becouse the thing is still pulling hard as hell. thanks for all the help. and any more thoughts

[4.8t]

tuning with LTFT or wideband??

ltft and stft

[S2H]

ltft and stft

you might want to check it with a wideband too if you can...
get the LTFT's areound 0 and then make sure you dont hit PE...or filter it out for the sake of LTFT
then just add a little bit of fuel in the highest load cells to keep you safe...its about the only ting you can do other than fixing the power band issue...

[4.8t]

i wish i had a wb but i dont just YET.

[jimmyblue]

I think that cam is begging for at least a moderate
torque converter. And you want to have a look at
the speed density tune quality below 2000RPM, the
cam will affect it and tip-in mixture, the "bog" may
just be the time it takes for STFTs to bring you into
line (down low the MAF can't, in PE mode the closed
loop isn't, but if closed loop and bogging look at the
STFT locally over time and look for the O2s dropping
out or pegging high local to the event as an indicator.
Check that the "homemade exhaust" is not liable to
put O2s to sleep, at the low RPM/load preceding
your roll-on.

[4.8t]

ok i'm in sd mode maf turned off. and the bog really is more of a bog go bog go bog go at this area like your body jolts back and forth like some one taking of in a stick for the first time. and right at this point you can watch the timming drop and rise with the bog and go. hope that made since and its funny alot of time this point will have a 0 on the scan for stft but then again i don't stay there long so this could be why. but i did find this last time that i had +5,6's in this range so i just took some fuel in that area via the ve table and i'll see today what it does.this bog go thing was REALLY bad because i added fuel to try and fix some kr but when i found it didn't help i thought i took it all back out but maybe i didn't

[4.8t]

the exhaust all i did was remove the muffler and striaght pipe it so i don't think it should have effected it.