I have a RB cooler on it, we took the cooler out of the loop and put a longer line prom the pipe to the tank and it seemed to help a bit. Carb is open about 1mm. I listen to the other sedans and they come off of WOT and right to idle no hanging of RPM. I am starting to wonder if I have a carb problem. I do have a Picco evo 2 i can try that carb I guess. Sucks I have to wait a couple of weeks between races to try it. On the street in front o the house the traction is so bad i can get any good load on the car to see if it still hangs the rpm. Really just want to get it sorted before I overheat this motor and hurt it. Thanks for the help and ideas so far .