E85 Timing

When converting to E85 is there a need to adjust ignition tables if they were dialed in on pump gas? Is there a general rule to follow when making this conversion?

E85 has a higher octane of about 105 RON, compared to between 91 RON and 98 RON for pump petrol. The higher octane fuel actually burns slower, so for best torque you advance the ignition timing compared to pump fuel.