It involves a little fabrication work on the pipes, but basically you can move them where ever aslong as the direction of air flow stays the same. With the twin AFM's of a GTR it makes it a little harder to position them, but even just moving them away from the compressor housing a litlle reduces the strength of the pulsing air.
On RB25's i've seen them mounted just after the intercooler in the RH side under the front guard, just running extended wiring.
Or even on an off chance it could be your AAC valve playing up or even a coil pack on its way out too!