Hi, I'm belatedly upgrading my app framework to Vuforia 8 from Vuforia 6. I have successfully got the tracked objects placed where they appear with V6, but when not tracking I'm getting a different projection matrix between the versions, so my non-tracked objects are placed differently.:

The code is given below, and called at screen re-orientation. 

// Cache the projection matrix:

#ifdef VUFORIA_V8
        Vuforia::TrackerManager& trackerManager = Vuforia::TrackerManager::getInstance();
        const Vuforia::State state = trackerManager.getStateUpdater().updateState();
        Vuforia::RenderingPrimitives *renderingPrimitives = new Vuforia::RenderingPrimitives(Vuforia::Device::getInstance().getRenderingPrimitives());
        Vuforia::Matrix34F projMatrix = renderingPrimitives->getProjectionMatrix(Vuforia::VIEW::VIEW_SINGULAR, state.getCameraCalibration());
        qUtils.projectionMatrix = Vuforia::Tool::convertPerspectiveProjection2GLMatrix(projMatrix,1.0f,2500.0f);
#else

        const QCAR::CameraCalibration& cameraCalibration = QCAR::CameraDevice::getInstance().getCameraCalibration();
        qUtils.projectionMatrix = QCAR::Tool::getProjectionGL(cameraCalibration, 1.0f, 2500.0f);
#endif

For V6 I get:

data = {
      [0] = 0
      [1] = -1.86011815
      [2] = 0
      [3] = 0
      [4] = -3.30687666
      [5] = 0
      [6] = 0
      [7] = 0
      [8] = 0
      [9] = -0.00156250002
      [10] = 1.00080037
      [11] = 1
      [12] = 0
      [13] = 0
      [14] = -2.00080037
      [15] = 0
    }

And for V8:

{
    [0] = 0
    [1] = -1.45888376
    [2] = 0
    [3] = 0
    [4] = 2.59219289
    [5] = 0
    [6] = 0
    [7] = 0
    [8] = -0.033016853
    [9] = 0.00614670897
    [10] = -1.00080037
    [11] = -1
    [12] = 0
    [13] = 0
    [14] = -2.00080037
    [15] = 0
  }