09 C6 BTR Stage 4 Cam Bucking When Cruising

[LS ROB]

I am chasing a fix for bucking on my buddies C6. It was tuned from a 'reputable' shop and the car drive like shit for the lack of better terms. I have changed a lot in the tune from transmission tuning to raise the cruising rpm and a lot on the engine side but the car bucks pretty bad when cruising. The car is a A6 with a 3200-3400 triple disc lock up converter, ported heads and exhaust stock TB and intake. TR6 plugs gapped at .032." The VE table is a little inflated at cruising range in hopes to alleviate this issue. I have lowered cruising spark, added fuel, lowered minimum air flow to no avail. It is better but you really feel it when the converter is locked. If it is under load even at the lower RPMs you don't feel it. I have used this forums advice on some of the things. I will attach the most recent log and tune. Any insight is greatly appreciated.
Attachment 130889Attachment 130890

Not sure if i can be of any help but hoping to gain some insight and maybe spurn some ideas to try. I have an ls7 that does this same stuff at light throttle/steady state cruise. Been fighting it for well over a year it seems. Ive tried everything i know and have been told to try with no luck. I even went as far as having the car tuned by an actual tuner. If you look in your log, it will be the small half a degree change in timing that you are feeling. I have a wideband and my AFR spikes lean for a split second when this happens. Your AFR will fluctuate, MAP & Throttle position changes, and from what im seeing in your log, MAF drops. Idk where it comes from as mine initially coincided with my over/under spark tables. Overspeed to be exact. Lowering BRAF seemed to help it the most but im still searching for a fix myself. Good luck with it.

[morepowerjoe]

I don't understand why you have PE delay set to 700 rpm. And I don't know why you insist on locking the tcc up in 4th at 50 mph. That will definitely cause bucking. Try locking it only in 6th gear at 55 mph and see if the bucking goes away