Heads/Cam Z06,Torque Management Adv Pulling Spark Causing Bucking at Low Rpm Cruise

[Tally TransAm]

Upon searching this seems to be a known issue a few people have experienced but I have not been able to find an exact solution.

Car is a heads/cam/bolton 08 Z06, actually has the LPE 660 package. Camshaft specs are 243/259 691/702 112 LSA. Car starts fine, idles fine, trims in line, dynos well, but there is an issue with light throttle input cruising in higher gears below approx 1700-1800 rpms.

Basically torque management advance begins to pull large amounts of timing (10-15 deg) in these large rapid spikes which causes the bucking. Torque management in the tune is all shutdown. I have read the issue is related to spark smoothing. I lowered the values in 6th gear (the most effected) and it made a minimal difference but certainly didnt correct the issue.

Any one have an exact fix for this, I was thinking of lowering the base timing in this area to see if the spark swings would be less and consequently have less feel. I attached a tune, unfortunately i did not save a data log of the problem, but like i said tm adv is pulling rapid timing spikes which is the cause of the bucking.

Thanks
Ryan

[rynez06]

Upon searching this seems to be a known issue a few people have experienced but I have not been able to find an exact solution.

Car is a heads/cam/bolton 08 Z06, actually has the LPE 660 package. Camshaft specs are 243/259 691/702 112 LSA. Car starts fine, idles fine, trims in line, dynos well, but there is an issue with light throttle input cruising in higher gears below approx 1700-1800 rpms.

Basically torque management advance begins to pull large amounts of timing (10-15 deg) in these large rapid spikes which causes the bucking. Torque management in the tune is all shutdown. I have read the issue is related to spark smoothing. I lowered the values in 6th gear (the most effected) and it made a minimal difference but certainly didnt correct the issue.

Any one have an exact fix for this, I was thinking of lowering the base timing in this area to see if the spark swings would be less and consequently have less feel. I attached a tune, unfortunately i did not save a data log of the problem, but like i said tm adv is pulling rapid timing spikes which is the cause of the bucking.

Thanks
Ryan

disabling spark smoothing definitely helps, as well as lowering the base timing in those areas (sometimes as low as 28-30 degrees) helps. With a cam that large I personally have never been able to get the car silky smooth at 1500 rpm and below.

[Tally TransAm]

so just disable spark smoothing completely?

any adverse side effects?

the car is out of town so I cant really tinker with it. Ill be seeing it again in a couple weeks

[rynez06]

so just disable spark smoothing completely?

any adverse side effects?

the car is out of town so I cant really tinker with it. Ill be seeing it again in a couple weeks

yes i disable it entirely, i havent seen or felt any adverse side effects