Limiting frame rate

i know how to limit the frame rate in X-code after compilation from Unity but I need to impose the same fps limit in Unity because the difference is making it difficult to get my sound design timing accurate. How can I do this?

come to think of it there shouldn’t be a difference between Iphone Unity
using this sort of code (which i have done religiously)

		t = 0.0;
		while (t < 1.0)
		{		
			t += Time.deltaTime * speed;						
			transform.position = Vector3.Lerp(startPosition, endPosition, t);
			transform.rotation = Quaternion.Lerp(startRotation, endRotation, t);
			yield;		
		}