i got the same idea since i have tuned my ecu at its max then realised that a vnt15 ( GT1749VA) can Really Produce 25.5PSI at daily run but turbo will live max 50 000km and will be razor shaped used on compressor whell ,
it was at this time ive got this idea ,, one vnt15 for hexaust 1-3 another one for hexaust 2-4
you delete airbox , relocate batterie in the trunk
and you salvage a 2.0L AEG hexaust manifold that wou will Rebuild 1-3 and 4-2 side by side at the place of airbox/battery
you mount 2 Borg & warner KP39 insead of Vnt 15 because supossly they are smaller
hexaust 1 and 3 drive the first turbo , hexaust 4-2 drive the other ,
add another intercooler on driver side then blend the output of the 2 intercooler in your intake at oem location
for n75 , you need to run both turbo at max spool , ( no actuator crank'd at max )
then add a blowoff valve on your compressed side or hack a BEW intake trottle body to use it as a blowoff valve ,
route your blowoff to n75 and its Absolutly possible that it work in reverse that should be ,
in this case you will need to invert totally the n75 duty cycle map
for oil line circuit , a flexible oil line goes on 1st turbo , oil return of this one goes into feed in of turbo 2 then return of turbo at it oem location on engine
it sould produce the same performance as my overclocked1749V but without hurting turbo'S
also will probably produce faster boost response , because turbos will be always ready ,
this si my dream , not yet started in real , not sure if ive finished to run it with succes in my head
your idea will work , i can bet on this 20$ lol
also possible to do the same thing for turbowing a 2.0l AEG with agt1749V , but ecu dosent take it at all , need to megasquirt it and was not my tea cup , abandonnedthis project years ago