Help me solve Ad-hoc lagging !!?!

[TakumiGT]

Hi, im currently still playing GT PSP with my friend via ad-hoc mode in the game. But the problem is, the fps seem drop in half when I begin enter the room in ad-hoc. When I play offline, the game work just fine and smooth at 60 fps. Im using Android and GT EU ver 2.0. Can anyone help me solve this problem please ? Thank you so much !!!