For extra thread info, this is what the dyno chart looks like for the Metro's G10 engine. I pulled the torque info from the
BSFC chart we have in the wiki for the G10 and then calculated horsepower in excel and plotted both on the graph.
As we can see from this graph, at my cruising rpm of ~2200 (45 mph), I have on tap roughly 24 horsepower. This is more than enough on flat ground, and almost always enough to climb the hills on the way home. In winter I do loose a few mph while maintaining peak BSFC at around 75% load (
calculated via the BSFC info we have in the wiki).
If I end up making the header, I'll do an A-B test to get a before and after shot of how the header effects the torque curve.