Interesting.
I swapped out the OE intake hose (between the snorkel and the air cleaner housing) for a 3" pipe, (the original necks down to 2" at the water trap) and chopped the reducing spiggot off the snorkel box (ID 53mm/2.0625") yeas ago (no other mod at the time).
Result.
Nothing my bum dyno could detect.
Same result fitting a K&N filter (and long ago removed)
Often, one thing on it's own will show nothing, but in combination with other mods show an improvement. The old "the whole is greater than the sum of its parts".
What did make a large difference to my vehicles bottom end pick up (turbo spool up) was fitting a 3" mandrel bend exhaust. (max EGT's also dropped 20-30* on my test hills) Then an even greater improvement with tweaking the pump.
