[Serum]

At some point the wire thickness and resistance plays a part. No matter how hard you cool it. :)

That optimum point; I think it might be a bit more complicated and setup-dependent. Artur could elaborate on that much better than I ever can.

It also depends on timing. These new controllers with a timing-boost should be able help to get a higher top-end as well (I mean the ones that up their timing towards the end of the end-rpm) Never found a movie on youtube to back this theory though