Major power loss after a few minutes of driving~ Sorry kinda long

[89ntrcptr]

ok heres the deal, when i first fire my car up and take it out it seems as if she has all the power in the world, feels as if you are hitting nitrous when it gets into boost in 2nd, but then after the car is warmed up it has no where near the power, it still gets into boost and gradualy climbs but no where near the way it does when its cool. say same speed in 2nd u cant realy feel it get into boost but u look at the gauge and its making the same amount, but is so much slower u dont feel the boost, when its cool it just screams when it gets into boost, what could be causing this? i have to wait for the car to cool all the way down for a couple hours just to get that feeling when the boost kicks in, i have a novi 1k with a basicaly stock motor with headers, offroad h-pipe, was running the fmu with 19lbers, well not to long ago i upgraded, got a 255 pump, 42's, prom 80mm maf, and adj reg, and put a f-150 crank pulley on, first time i took it out the motor was cool, OMG felt so strong, drove it a few more minutes and it just falls flat, after its warm even with the addition of these mods and couple more pounds of boost it feels just as fast as it was when i had less boost and stock fuel system, it just dont seem to have the get up and go when it warms up, Plz help me, this is bugging the hell out of me, if i cant have a supercharger make the power i want for more than a just few minutes im going to go insane