Evo X wont accelerate or speed up at cruse

Hello :) so I have a used 2013 Evo X GSR with 40 k miles and im having a problem where if im at cruising speeds around 70-75 and I try give it gas nothing happens, doesn't rev up or speed up, ill keep my foot on the gas and it takes a couple of seconds before it kicks in again and I get a small increase in speed then I lose power again and I hear the blow off valve go off and this problem seems to go away when I turn the car off and it looks like its been happening at night, help please!!!