None. I have a smoker machine tester which pumps smoke inside the engine.
It's absolutely amazing!
https://www.ebay.co.uk/itm/SMOKE-Dia...72.m2749.l2649
Someone on this forum suggest the turbo actuator as I had it off and messed. I'm running a 19T and getting the rod in the right place was a real pain and it was never right. I removed it and found it's been rubbing on the oil return.
lucacarmods.com sells a kit to location it into the correct place. I fitted one and now i'm seeing a power increase and no stalling (YET)
The kit did not 100% fit as I have a aftermarket 19t cold side and silicone hose but I made it fit.