So background is, I have a MK6 GTI IHI turbo thats been retro fitted to the 1.8T 20V in my Polo 9N3. To get the compressor exit pipe to fit I had to cut off the muffler/canister on the compressors outlet pipe and weld on a plain elbow in its place. Now this turbo, despite it being on a 1783cc vs a 2L engine, spools very early at small throttle openings. I'm getting what feels to be a compressor surge where it starts to boost and despite no throttle pedal change you can feel it go flat, then want to run up again etc. To my mind its comp surge but it surprises me how low in the rev range its happening. Now I made a similar mod to a K03s (standard 1.8t 20V turbo) at one stage and it behaved similarly leading me to think that the turbo muffler also acts as an expansion chamber that moves the surge line. But I cant be sure back to back if the tune wasnt changed back then too.

Sooooo.... what I'm wondering is, have any of you guys found that the fitment of a turbo muffler delete to the factory GTI MK6 turbo resulted in a low rev spooling surge? If its happening for me on 1.8L then to my mind it might show up more readily on a 2L engine. It could be that your electric DV is operating with some magic to mitigate it, but either way I'd love to hear whether this is a thing or not?