I'm playing around with my timing (trying to get a little more advance) and after I logged a pull and let off the throttle it backfired. It was at @7700, 20 load (2 byte), 10 counts of knock. My question is did the knock register because of the backfire or is the backfire caused by the knock? Logically I can see both.

 

In most cases the backfire is just a cause of having a pretty rich AFR. When it gets so rich and you have been beating on the car for a bit the hot exhaust and turbine assembly can ignite the rich AFR exhaust gases and lead to a backfire. 10 counts is a good bit of knock though. What were the AFRs?