I appreciate this is likely old news, but in the interests of sharing.....there's a lot of interesting info in this (6 year old!) thread -
http://www.vwgolf.net.au/showthread.php?11812-Forge-Wintake-amp-MAF-sensor-read-issueAccording to that thread, the Volant intake shows 3% trims and was the one the tuners in that thread recommended back in 2012. The info and testing relates to the MK6 R, so very relevant to ED30 owners.
Other useful little nuggets I picked out of that thread:
The top end AFRs can be 0.5 leaner than requested if the trims are not correct, which is dangerous at 2+ levels of tune.
Most of the tables in the ECU rely on accurate MAF readings, therefore it is recognized that software tuners don't (or shouldn't at least) modify the MAF table, otherwise the engine would be locked down to a particular intake for life and skew other calibrations.
The regular K03 engine doesn't seem to suffer with wild fluctuations as much as the KO4 engines. Must be a flow dynamics difference between the two compressor wheels.
This little beauty
http://www.42draftdesigns.com/fsi-oem-style-maf-housing/ Hats off to them for that one. Very neat.
Adding a laminar grid has shown improvements.
And some other bits n bobs.
In other news, Revo 2+ continuing to drive very nicely indeed with the stock intake. Kept up with a new shape 335d no problem on the way into work this morning, so that's a good sign things are healthy as they are bloody quick in the midrange.
Cold starting and hot and cold idles are also considerably better compared to the Revo intake. As is part throttle smoothness.
Thinking of just throwing both intakes onto ebay to be honest. Feeling a bit indecisive. I don't think the modest top end gains are worth the high price of the intake, the noise, or the idle/part throttle rubbishness in all honesty.