Thread: please dont tell me this is knock

hmmm, sounds like what my car is doing under heavy throttle, stock m90 stock pulley

What kind of flow mods would you say would work? i have a 2.5" dp, would getting a 3" really do anything? Well above headers was suggested but dont headers just raise the powerband? I kind of want to avoid that.

But i just dont get how all of the sudden it just starts doing it