diff --git a/src/collision/Manager.js b/src/collision/Manager.js
deleted file mode 100644
index e996ba9..0000000
--- a/src/collision/Manager.js
+++ /dev/null
@@ -1,118 +0,0 @@
-/**
-* _Internal Class_, not generally used outside of the engine's internals.
-*
-* @class Manager
-*/
-
-var Manager = {};
-
-(function() {
-    
-    var _pairMaxIdleLife = 1000;
-
-    /**
-     * Description
-     * @method updatePairs
-     * @param {object} pairs
-     * @param {collision[]} collisions
-     */
-    Manager.updatePairs = function(pairs, collisions, timestamp) {
-        var pairsList = pairs.list,
-            pairsTable = pairs.table,
-            collisionStart = pairs.collisionStart,
-            collisionEnd = pairs.collisionEnd,
-            collisionActive = pairs.collisionActive,
-            activePairIds = [],
-            collision,
-            pairId,
-            pair,
-            i;
-
-        // clear collision state arrays, but maintain old reference
-        collisionStart.length = 0;
-        collisionEnd.length = 0;
-        collisionActive.length = 0;
-
-        for (i = 0; i < collisions.length; i++) {
-            collision = collisions[i];
-
-            if (collision.collided) {
-                pairId = Pair.id(collision.bodyA, collision.bodyB);
-                activePairIds.push(pairId);
-                
-                if (pairId in pairsTable) {
-                    // pair already exists (but may or may not be active)
-                    pair = pairsTable[pairId];
-
-                    if (pair.isActive) {
-                        // pair exists and is active
-                        collisionActive.push(pair);
-                    } else {
-                        // pair exists but was inactive, so a collision has just started again
-                        collisionStart.push(pair);
-                    }
-
-                    // update the pair
-                    Pair.update(pair, collision, timestamp);
-                } else {
-                    // pair did not exist, create a new pair
-                    pair = Pair.create(collision, timestamp);
-                    pairsTable[pairId] = pair;
-
-                    // push the new pair
-                    collisionStart.push(pair);
-                    pairsList.push(pair);
-                }
-            }
-        }
-
-        // deactivate previously active pairs that are now inactive
-        for (i = 0; i < pairsList.length; i++) {
-            pair = pairsList[i];
-            if (pair.isActive && activePairIds.indexOf(pair.id) === -1) {
-                Pair.setActive(pair, false, timestamp);
-                collisionEnd.push(pair);
-            }
-        }
-    };
-    
-    /**
-     * Description
-     * @method removeOldPairs
-     * @param {object} pairs
-     */
-    Manager.removeOldPairs = function(pairs, timestamp) {
-        var pairsList = pairs.list,
-            pairsTable = pairs.table,
-            indexesToRemove = [],
-            pair,
-            collision,
-            pairIndex,
-            i;
-
-        for (i = 0; i < pairsList.length; i++) {
-            pair = pairsList[i];
-            collision = pair.collision;
-            
-            // never remove sleeping pairs
-            if (collision.bodyA.isSleeping || collision.bodyB.isSleeping) {
-                pair.timeUpdated = timestamp;
-                continue;
-            }
-
-            // if pair is inactive for too long, mark it to be removed
-            if (timestamp - pair.timeUpdated > _pairMaxIdleLife) {
-                indexesToRemove.push(i);
-            }
-        }
-
-        // remove marked pairs
-        for (i = 0; i < indexesToRemove.length; i++) {
-            pairIndex = indexesToRemove[i] - i;
-            pair = pairsList[pairIndex];
-            delete pairsTable[pair.id];
-            pairsList.splice(pairIndex, 1);
-        }
-    };
-
-})();
\ No newline at end of file