Advance timing

Hi, has anyone here advanced their timing ? If so how much degrees did they change? And what benefits did you get thanks?

Bump

i doubt if you would see any gains eddie, mine recorded 3 more hp when i retarded it 10 deg (at the bromsgrove group dyno session, printout in one of my blogs on here) tho it made the car sluggish/hesitant low down, and i re-advanced it on the way home.
but going by my running n/a this week, i think there are gains to be had by altering the whole sparkmap tho

Thank you frank