Believe it or not it actaully cools down the intake once the car has been runing a while. The heat from the block radiates into the intake (Especially our Duratech!)
So there is NO benefit to doing such a mod. It's probably a placebo effect they feel (the need for it to work)
BTW - If you are thinking it will help during first start up; it won't. The thermostat is closed until the engine heats up. Not only that, but the engine is in closed loop mode. Besides no one in their right mind would go race their car if it wasn't properly warmed up. That's just asking for engine damage...
Isn't the ECU coolant temp sensor located in the manifold? If so, then the engine would stay in closed loop mode too. (I.E. NO Performance!)
