base timing in gear vs high octane question

[Kurtomac]

trying to get to the bottom of my bucking...its much calmer than it used to be...after i give this a try...next step is upgrading to cos3 or 5
and select different afr's in the area where im bucking....50-60kpa 1400-1900 area
anyways...checking out stock timing tables for 02Z06 ....idle timing in the base is gear with throttle closed is a lot lower than idle region that the same area in the high octane table and timing is different at the same values say .20 g/cyl at 2000 rpm in each table(question...my car being ETC....TPS is never 0 or closed...so is it actually using the in gear table or running of the high octane table?) but one thing i was thinking maybe at those light throttle/decel to accel transitions where it gets a little bumpy not sure if I need more timing or less timing on off throttle/decel areas than in the light throttle/on throttle area using the high octane table as my timing selection....if i match my timing tables as ive been doing...even though the base table isnt broken down as far as the high octane table rpm wise, I did this so when i interpolates between the table timing wouldnt bounce so much causing the bucking...but you guys know more than me...maybe my car is wanting more timing or even less timing at decel/throttle(app i assume) and might help with bucking....because ive had this bucking the whole time ive been cammed and nothin really seems to help a lot....if anything...bucking is worse as light throttle ie the point where its almost decel...but very light throttle...it doesnt really buck on decel so maybe you guys can figure out my issue
Im probably being picky and who knows if what i was saying even makes sense but im trying to figure this out....the car actually drives fairly well for the size cam im running
its a stock stortblock ls6
TFS 215 heads 11.1:1 CR
235 243 620 623 111+3 LSL comp cam...recently changed out from my old 236 238 cam...thus all the tuning changes
FAST 92 Ported LS2 tbody ported
1 7/8 in headers 3in ORX
all supporting mods with 390 gears
SD tuned....currently LTFT turned off and have my STFTs on...i dialed in my 15-80kpa portion of my VE table with them while logging with my serial LC1... for reference
Im waiting on my replacment serial LC1 cable from TAQ before i finish up my 80-105kpa area
attached is my current tune...any pointers guys?

thanks
Kurt

[ArKay99]

Sounds like your going through what I went through a while ago. Check out this post. It may help. Surge-Buck fix (http://forum.efilive.com/showthread.php?t=8702)

[TFZ_Z06]

trying to get to the bottom of my bucking...its much calmer than it used to be...after i give this a try...next step is upgrading to cos3 or 5
and select different afr's in the area where im bucking....50-60kpa 1400-1900 area
anyways...checking out stock timing tables for 02Z06 ....idle timing in the base is gear with throttle closed is a lot lower than idle region that the same area in the high octane table and timing is different at the same values say .20 g/cyl at 2000 rpm in each table(question...my car being ETC....TPS is never 0 or closed...so is it actually using the in gear table or running of the high octane table?) but one thing i was thinking maybe at those light throttle/decel to accel transitions where it gets a little bumpy not sure if I need more timing or less timing on off throttle/decel areas than in the light throttle/on throttle area using the high octane table as my timing selection....if i match my timing tables as ive been doing...even though the base table isnt broken down as far as the high octane table rpm wise, I did this so when i interpolates between the table timing wouldnt bounce so much causing the bucking...but you guys know more than me...maybe my car is wanting more timing or even less timing at decel/throttle(app i assume) and might help with bucking....because ive had this bucking the whole time ive been cammed and nothin really seems to help a lot....if anything...bucking is worse as light throttle ie the point where its almost decel...but very light throttle...it doesnt really buck on decel so maybe you guys can figure out my issue
Im probably being picky and who knows if what i was saying even makes sense but im trying to figure this out....the car actually drives fairly well for the size cam im running
its a stock stortblock ls6
TFS 215 heads 11.1:1 CR
235 243 620 623 111+3 LSL comp cam...recently changed out from my old 236 238 cam...thus all the tuning changes
FAST 92 Ported LS2 tbody ported
1 7/8 in headers 3in ORX
all supporting mods with 390 gears
SD tuned....currently LTFT turned off and have my STFTs on...i dialed in my 15-80kpa portion of my VE table with them while logging with my serial LC1... for reference
Im waiting on my replacment serial LC1 cable from TAQ before i finish up my 80-105kpa area
attached is my current tune...any pointers guys?

thanks
Kurt

I see you have the DFCO disabled by using a high enable temp.
I would wonder if this is causing you any grief.

[WeathermanShawn]

Though many have reduced timing in those areas successfully to reduce bucking, I had far more success with dialing in B4307 idle airflow and especially B4309 Throttle Cracker Table.

I have read that whether reducing timing or airflow to address bucking on decel or light throttle, you are essentially trying to reduce the natural tendency of the engine to gain in speed or rpm's as you let off the throttle. Whether timing, fuel, or airflow, it will have a tendency to jump 'cells'..and the infamous bucking begins.

I noticed your Desired Airflow is quite high. Also, the Throttle Cracker. I went with much lower airflow in both areas. I also did not like how my car felt with dropping timing so low in those decel cells. I went back to a much higher spark advance at .008-.020 g/cyl, and simply matched my high octane spark and base timing tables to the same value.

I would say 95% of the bucking is gone. You know you have it right when on light throttle or decel the car just slowly lowers its engine speed. Whether you successfully do it through timing or lowering your Airflow is by experimenting.

Your cam is more aggressive than mine, but I tamed that annoying bucking by reducing airflow.