Hi everyone. Got a Sierra Cosworth track day car that overheats. Fitted with ally rad, header,4x4 waterpump,thermostat housing, swirl pot,82degree stat,Roose hose set. All new. Link storm ecu and pro2dash. Defo overheating as the figures on the dash correspond with heat gun readings taken. We don't have a heater or oil modine in the system and there is a Roose bypass hose fitted from rear of head back to the thermostat housing. Have checked the flow back to thermostat from rear of the head and there is loads. Has anyone heard of a restrictor needed to be fitted in this pipe to compensate for there not being a heater in the system. I'm assuming that the flow would be conderably less if the heater was in the system. Any suggestions or advise would be really appreciated as starting to run out of ideas. Thanks. Chas.