Which Neu Motor

I'm having another issue with maxamps and I'm not getting my battery, so this brings more questions to mind.

If the 1515 line of motors are 1500 watt motors, then on 4S the maximum constant current draw on 4S will be about 107A, right? If this is true, then the maximum constant current draw at 5S will be about 85A. This is assuming 3.5v under load and a motor turning about 30K rpm.

If this is right, then on 4S, I'd need a pretty "good" pack to keep up, but on 5S, I don't need such a hot pack to keep up. If this is the case, I could just run the 1515/2.5D on a truerc 5S 8Ah pack (for A LOT less than a maxamps 4S 8Ah pack).

If I decide to go with a 1512, it should be even better yet, because that should draw even less current.

Please tell me I'm right. LOL. If this is alright, I'll make the switch to 5S. The truerc 5S packs are only like a couple of mm taller than the maxamps 4S packs. The truerc packs are just a bit wider and longer, which isn't a problem.

Now I need to figure out what I'm going to be doing with these brand new Kokam 4S packs that I just bought.