[P-hack]

Yes, lots of compromises, you probably have considered it, but it seems like the liquid cooled volt pack can push 900 amps, and you already have some liquid cooling in your future it seems with these motors (and hotrodding).

But instead of paralleling another pack, I would series it, since those motors prefer high voltage. Another 39 leaf modules will get you to ~650v, considering how many motors you are feeding... It was designed for a ~100hp car, and you are looking for ~400hp, so more batteries is entirely reasonable.

Also it occurs to me that the boost converter approach seems to be limited to hybrids, where you have a engine-generator to power the drive motors when needed. I don't know of any straight EV's that use a boost converter. The hybrid battery mostly fires up the engine and adds some power back on accell from regen. The boost inductor is out of the way of the high power current flow. The boost switches have a very different reality than the inverter switches as well, and have to handle 3x the current on average (with high peak loads and voltages).

I'm currently thinking the boost converter is probably best avoided in an EV, relying on field weakening and other control tricks instead (or motor retermination/reconfiguring, but that won't help your battery hp demands, only more batteries will do that).