It's not only the weight and power. Wheelbase is slightly shorter in ChampCars, which means less weight transfer. Turbocharged engines respond in a different way, once they kick in they have a flatter rpm-torque curve.
Champ Cars had over 1.000 hp as recently as 2000, when JPM drove them. During the 70's, Champ Cars were definitely more potent than F1 cars. They've been using a 2.65 liters turbocharged V8 since I remember.
Champ Cars had undersides (kind of skirts), banned in F1. They develop most of their force from the tunnels in the underbody, allowing easier overtaking. This means that at slow tracks, like Laguna Seca, Bourdais was faster than Zonta by 1 second.
So, if you ask me, both series are very similar, the only difference is about 300 million dollars per season per team.
Besides, that's irrelevant: NHRA leaves an F1 car in the dust any day. The couple of dragsters you see at the starting line, at over 7.000 hp each, have more power than the entire F1 grid...
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(in fact I would like it evolves and crush IRL and becomes big like once it was Indycar series)
So, you don't need the national gross product of a small country to develop one.
