No idea, but one of the cars that I learned to drive stick in was a friend's 2003 Mustang Cobra. All cast iron engine and something like 400WHP. I don't know that the weight of the flywheel was everything, the crankshaft weighs a lot and I think even the moving mass of the pistons and rods translates into rotational inertia. Finally having 8 cylinders versus 4 means that your engine response time is theoretically twice as fast.

When the clutch engagement time is say 1 second and your engine is idling at 900 rpm you're only doing 1.5 rev/sec. In a four stroke, four cylinder engine that means you're getting on average 1.5 combustion events per second. In the 1 second engagement, you get 1 or 2 combustion events. In the 8 cylinder you get at least 2 and probably 3.

I thought about doing the math for how much energy is in a cylinder firing versus stored in the rotational inertia of the moving parts, but honestly I don't know that I really care. I know anecdotally that big engines make it easier to get cars moving for some reason, and that smaller engines make it a little more difficult. I just speculated as to why I thought that might be.