the closer you get to the intake manifold the more I would hesitate to modify anything.... the further away from the intake manifold (pre MAF closer to atmosphere) the more safe it is... I would even venture to say this is where most car manufactures cut corners to save money... Intake runners depend on several flow volume variables to equalize the air flow evenly to each cylinder you may just create idle, WOT issues and misfires which you don't want to venture into with a multi spark per cylinder car.

My advice... find a way to modify our crappy air box to be less restrictive and don't mess around with anything past the maf going toward the intake manifold.... runners need the OE enginnering.

now you can see why it is safe to modify intake pre maf... Maf still straightens the air properly for calc.... sometimes even better when there is less restriction and no obsticles (smooth tubing for the intake) creating uneven air current.

I use to have a Stage III Volkswagen GTI from APR tuning... the turbo collected air so fast with so much pressure the one and only silcone intake elbow would collapse. The airbox did not have enough inter volume to handle the turbos need for air.... the airbox even had to be modified with an air horn to collect air and straighten air it even before the MAF cause the turbo was sucking so damn hard and the maf could not send a good signal cause the airflow has so much current....

I.E. out with the the airbox.... new solid intake elbow and wider mouth to the collector horn that was once inside the airbox, now it is inside an open element K&N.... Al la ChrisG enginnering.

Pics below





Hope this helps... Kids are one now, in good health, advancing out of premature birth issues day by day.... pretty cool being a dad to the power of 3 instantly.

Now you know why I have a Crossfire... My little piece of vacation on 4 wheels. Kids were NOT products of fertility drugs.... my wife has twins in her genes... we are very blessed.