car sluggish after few mins of running

cant seem to figure this one out. car runs fine and is very strong for about the first 10 mins of driving it then when i have to stop for a light or something and then start to accelerate it almost feels like im towing something.. car seems to lost most of its power.. if i give it more gas u can really tell its running sluggish... car has a 2001 saleen s281sc motor and tranny setup in it with computer and all the wiring from the saleen... if anyone knows what i can check on it that may be the problem i would be thankful.. i have no check engine lights or anything on other than the airbag and abs lights cause i unhooked those items

im not sure if the guage is working correctly or not but the ic seems to never get above 75-80 the pump and fans on the ic run all the time when the ignition is on and the temp guage for the motor stays about mid way.

no pretty much just finishing up the car been swaping this motor and stuff in since february its in a 89 coupe... is there a fuse i may have blown? i did pop a fuse one day when i was messing with the harness to the ic temp and boost guages... thought i changed the fuse out but i may have changed a different one that was bad.. my boost guage never seems to work is there something i can check to make sure the sensor is working?