how to fine tune between shifts

[cdritter]

spent 9 hours on dyno the other day, driveability is great, wot is great, just have a loud backfire between shifts if i shift fast as like you would racing. wot shift and wot. Any suggestions on how to tune this out, thanks

[S. Armish]

It is probably too rich in the high RPM, high vacuum area of your fuel map.

SA