[Tervuren]

the ruling bodies of each try to dictate a rules package with track layout and safety in mind.

If F1 didn't change their track layouts, adding chicanes, etc, then the performance of the F1 car would have to be dialed back by the ruling body.

Indy has to run at tracks where there isn't run off. They'd lose their audience if they put in chicanes.

This means they have to dial the cars back via the rules much further than F1 as they have less control of safety via track changes.

Safer barriers have helped Indy cars be at very high speeds, but the Indy cars could be much faster if they added Chicanes on each straight of Indy...(Imagine the outrage!)

In both F1 and Indy, whatever the teams come up with to go faster than intended will result in a new set of rules with speeds in mind.

In terms of spending, this is not so much dictated by the rules but by the value of the money stream to the teams. Teams will find a way to spend their money no matter what attempt is made to cut costs.

The rise of virtual testing came about from attempting to cut costs by limiting real testing. It is possible that this has made it even harder for starting teams as the process of calibrating virtualization without testing is extremely difficult.

Tires also play a part, what sort of degredation is the series aiming for? You can compare one lap runs, but what happens when you go longer? Porsche did their wide body 911's not for qualifying speed, but for the long run advantage.

An aspect that hasn't been mentioned is that you could take the budgets for Indy Car and make a car that is much faster than a F1 car. It just would not be eligible for either series.

Both series are limiting the potential for lap time according to track adaptions and their view of what results from budget and knowledge of the teams.