[classicauto]

In regards to the exhaust being choked on the smaller turbo...

What if you approach the manifold design from a EMAP standpoint, forgetting about spool at all for a second.

Example: Twinsturbo FD. Sure you've seen the crazy long, multi bend labyrinth manifold. Responsive no, but 1:1 pressure ratio - yes. Wastegate is a straight shot from the runners (although they curve all over the place) while the turbo is actually 90* to them. Aaron's manifold is similar, wastegates are a straight shot out of the port, while the turbo is getting its feed on after them..........again, low backpressure.

Perhaps the best layout for the exhaust would be to favour flow to largest then smallest "vents" as possible. Maybe wastegate(s), large turbo, then small turbo. Once everything's closed up at low RPM and you hammer the throttle, the physics of the smaller turbo vs. larger should itself spool one before the other, and hopefully plumbing in the order of largest to smallest will allow enough flow for the power needed up top without making EMAP unreal.

One would imagine, given the rotaries exhaust power, that the simple physics of the two turbos in the system would create decent spool for their size even if flow was directed entirely to the gates. As long as the gates are closed and some of the pressure building is pushing on the turbos, they'll spool while the flow favouring the gates should keep pressure as low as possible.

????