[Jeff86]

Yeah I agree... maybe not slamming closed since it's revving and would be open, but it does sound like something mechanical is "catching". I don't believe that's knock, but I can certainly see the sensor picking it up.

Edit: It's hard to tell, but it could be throttle slamming closed if you are instantly releasing after stabbing the throttle or perhaps reaching the end of its travel on open?

I like those wheels btw!