As far as i know, 80kph is the real speed limit. This one's from Republic Act 4136, otherwise known as the "Land Transportation and Traffic Code". As far as i know, this one has not yet been amended.

CHAPTER IV
TRAFFIC RULES

ARTICLE I
Speed Limit and Keeping to the Right

Section 35. Restriction as to speed. -

(a) Any person driving a motor vehicle on a highway shall drive the same at a careful and prudent speed, not greater nor less than is reasonable and proper, having due regard for the traffic, the width of the highway, and of any other condition then and there existing; and no person shall drive any motor vehicle upon a highway at such a speed as to endanger the life, limb and property of any person, nor at a speed greater than will permit him to bring the vehicle to a stop within the assured clear distance ahead.

(b) Subject to the provisions of the preceding paragraph, the rate of speed of any motor vehicle shall not exceed the following:


MAXIMUM ALLOWABLE SPEEDS Passengers
Cars and Motorcycle Motor trucks and buses
1. On open country roads, with no "blinds corners" not closely bordered by habitations. 80 km. per hour 50 km. per hour
2. On "through streets" or boulevards, clear of traffic, with no " blind corners," when so designated. 40 km. per hour 30 km. per hour
3. On city and municipal streets, with light traffic, when not designated "through streets". 30 km. per hour 30 km. per hour
4. Through crowded streets, approaching intersections at "blind corners," passing school zones, passing other vehicles which are stationery, or for similar dangerous circumstances. 20 km. per hour 20 km. per hour


(c) The rates of speed hereinabove prescribed shall not apply to the following:

(1) A physician or his driver when the former responds to emergency calls;

(2) The driver of a hospital ambulance on the way to and from the place of accident or other emergency;

(3) Any driver bringing a wounded or sick person for emergency treatment to a hospital, clinic, or any other similar place;

(4) The driver of a motor vehicle belonging to the Armed Forces while in use for official purposes in times of riot, insurrection or invasion;

(5) The driver of a vehicle, when he or his passengers are in pursuit of a criminal;

(6) A law-enforcement officer who is trying to overtake a violator of traffic laws; and

(7) The driver officially operating a motor vehicle of any fire department, provided that exemption shall not be construed to allow unless or unnecessary fast driving of drivers aforementioned.

Section 36. Speed limits uniform throughout the Philippines. - No provincial, city or municipal authority shall enact or enforce any ordinance or resolution specifying maximum allowable speeds other than those provided in this Act.

Section 37. Driving on right side of highway. - Unless a different course of action is required in the interest of the safety and the security of life, person or property, or because of unreasonable difficulty of operation in compliance herewith, every person operating a motor vehicle or an animal-drawn vehicle on a highway shall pass to the right when meeting persons or vehicles coming toward him, and to the left when overtaking persons or vehicles going the same direction, and when turning to the left in going from one highway to another, every vehicle shall be conducted to the right of the center of the intersection of the highway.

Section 38. Classification of highways. - Public highways shall be properly classified for traffic purposes by the provincial board, municipal board or city council having jurisdiction over them, and said provincial board, municipal board or city council shall provide appropriate signs therefor, subject to the approval of the Commissioner. It shall be the duty of every provincial, city and municipal secretary to certify to the Commissioner the names, locations, and limits of all "through streets" designated as such by the provincial board, municipal board or council.