Your ram air system will have absolutely no (or very little) effect on the operating temperature of your engine. In fact, the colder the air the better off your engine is. When you worry about engine temps, that's when you worry about the cooling system of your car, but for you, go ahead, you will have no problems whatsoever, just make sure you can stop water from getting into your intake. That'd ruin a good day pretty quick.
If you're really interested about engine operating temperatures, here's the nitty gritty. High performance cars in places other than the States like to run a bit cooler (on the order of 75~85*C). Simply put, the colder the engine, the more power you're going to make. There is a trade off, however. Notice how I said "outside of the States." When you run your engine cold, you're also running less efficiently and creating more pollution. That's why some modern cars here have thermostats which OPEN at 85~90*C, which helps to lower emissions greatly.