What would cause this?
 

So I'm playing around with the fuel in MS, between like 4-5300 RPMS @ WOT there is a random popping noise coming from what I assume to be the WG dump tube. It's not detonation, I'm thinking it might actually be running too rich and backfiring? The AFR reads just under 11 at WOT

By "under 11" you mean in the 10's? And by "dump tube" you mean your WG is VTA?

Yeah, me thinks it's probably afterfiring.

AFRs in the mid to high 10s are perfectly fine.... but I'm not sure what you are experiencing might be. :dunno:

Yea sorry lol it was reading in the mid tens. The WG is a Tail 38mm VTA with about a foot long pipe. It sounds fucking awesome @ WOT. Anyways, I leaned it out a bit, like mid to high elevens, and the problem didn't go away. Now I'm really confused. I have tried making it very rich (like 9:1) and then leanish (didn't go above 13:1 AFR) and it still does it...