Strange knock (tap) noise

[CJ_Derv]

Hey guys,

Now i may be being daft here, but since fitting the TD04 ive got a tap ( knock) noise now and then against the bulkhead, there is roughly 5mm between turbo and bulkhead and doesnt touch when idle or revd standing, now i havent had a proper look but thinking maybe exhaust against tunnel with new turb, or the actual turbo itself

Now its wierd because it doesnt always do it, it mainly does it if i jolt the throttle, ie press and release quickly, or sometimes when change gear,

i coudl possible do with checking top mount as had this go before just cant get my head round it and it irritates the shit outa me its that loud when it does it people walking by hear it lol

any idead guys?