On 2003-08-09 02:56, 1 Bad 88 GT wrote:
IMOE on a stock vehicle you gain lowend torque when you advance the timing and you tend to lose a little topend. The opposite is generally true as well, when you retard the timing it will increase the topend and lose lowend torque. This is not set in stone or true in all cases but it has been my experience.
That's probably because the maximum advance is (close to) right on, while in the knock sensitive range between idle and about 3500 rpm, the advance curve is set conservative, to avoid problems with knock.
Advancing the entire curve brings the low rpm timing closer to optimum (assuming that knock is not a problem), while the maximum advance may be a bit too much.