Lol, didn't realise that about a specific tune needed for the IE manifold! Their's seemed really decent with the CAD optimized velocity stacks....all the good stuff. What a shame!
It reminds me of HPA's intake for the R32. Someone fitted one and it lost 50lbft over the standard intake immediately
Lots of forum debate about it. HPA got involved and said (surprise surprise) "you need our special cams and tune to get the torque back". But it never did get back to standard levels of torque with those extras! It was primarily designed for forced induction, but losing that much torque didn't win them many customers iirc.
I think the same is true of HPA's own TFSI intake. "Yeah, you need our tune otherwise it won't run properly".
Seems to be a bit of a theme with the Americans. They go bigger and better on the flow but it royally messes with the engine dynamics, so they have to then mess around with the ECU to try and get you back to where you started with the standard manifold
So erm, yeah, squirt the meth into the standard intake!