I have tested the 41032 with the prototype engine last year. It's a much shorter manifold, giving you higher top-speed, but I haven't been happy with the bottom power in the thight infield sections of the track. As said before, I have come back to the standard 2068 pipe with standard manifold always. It just seems to be the best combination for this engine, working on short and thight tracks as well as on wide and flowing tracks.