I am yet to be delighted by my twintercooler, but I am at REVO tomorrow to see why it feels less responsive than before fitting. I'll report back, if I had my time again I'd go straight for the THS
Bigger area to fill with air compared to standard so will result in more turbo lag. Revo should ba able to adjust your settings to make it better.
Sorry to say, this does not appear to explain the performance, lag via this level of volume increase is potentially a miconception. I had a long conversation with a friend who is probably one of the best UK race engine mappers and veryexperienced with turbo motors (Including Lemans). Okay a different league to road cars, but he said to me categorically on a turbo motor of this configuration the increae in volume will not be noticeable.
Do a little match and even at 3,000 rpm the GTi will be consuming 50+ litres of air, I don't know how many litres the full inlet track is but the upstream impact will be very little in additional time to fill. The other point is that the reduction in pressure differential will go down and hence the required boost at the turbo to meet inlet boost will be slightly less
I hope Revo can bring back the 'drive' pre intall