Lechlis
Well-Known Member
I may have stumbled upon something interesting for those of us with manual transmissions.
When I am out for a spirited drive, I notice a power lag on quick shifts. Initially, I assumed it was turbo lag. After looking at the logs though, I found that the ignition timing was dropping significantly and taking approximately 1 second to recover once back at WOT.
In the picture below, the two vertical green bars represent 1 second. The top purple line is manifold pressure and the white line just below it is spark. There are two shifts in this picture and both times there is a delay (Poorly circled in red) before the ignition timing returns to the number specified in the timing tables.
I found that in the Transmission -> Torque Management tab there is Abuse Mode and Torque Reduction. I had always thought this would be ignored because this is a manual transmission vehicle, but I wondered if abuse mode might be kicking in, so I zeroed out all four of these tables. I was skeptical since it refers to transmission temp, but figured it could not hurt. Below is a snip of the HP Tuners screen.
Anyways, here is a snip of the first drive after making these changes. The timing lag is gone. There is still some true turbo lag as seen in the purple line, but the pick up after a shift is now much better.
When I am out for a spirited drive, I notice a power lag on quick shifts. Initially, I assumed it was turbo lag. After looking at the logs though, I found that the ignition timing was dropping significantly and taking approximately 1 second to recover once back at WOT.
In the picture below, the two vertical green bars represent 1 second. The top purple line is manifold pressure and the white line just below it is spark. There are two shifts in this picture and both times there is a delay (Poorly circled in red) before the ignition timing returns to the number specified in the timing tables.
I found that in the Transmission -> Torque Management tab there is Abuse Mode and Torque Reduction. I had always thought this would be ignored because this is a manual transmission vehicle, but I wondered if abuse mode might be kicking in, so I zeroed out all four of these tables. I was skeptical since it refers to transmission temp, but figured it could not hurt. Below is a snip of the HP Tuners screen.
Anyways, here is a snip of the first drive after making these changes. The timing lag is gone. There is still some true turbo lag as seen in the purple line, but the pick up after a shift is now much better.
Last edited:
