We have been staging between 130 - 140 running 200ft in the mud crossing the line @ 180 - 190 hitting 200 on the return then shuttin down 200-210, It takes around 4 min to cool off to 100-120 with the engine off and the pump & fan on, We see a 40 to 50 degree temp rise in around 3.5 secs @ wot, I have a single pass rad with a 2800 cfm fan with no fan shroud, Don't have too much room in between the moroso electric pump and the single pass rad around 1/4", The fan is mounted in front of the rad pulling air out of the front of the truck to help clear the rad fins,so I dont run the fan during the pass, I switch it on @ the turn on to the return road, We have been gettin along with this set up for 4 seasons without overheating....But we have plans to run out of state in @ a 300ft track... so its time to up grade,Current rules state cant fool with the fire wall so I can only go forward, Trying to keep the stock grill in place so any one got any ideas