it doesn't work like that. They are truly independant of each other. I can shut off an engine and run single engine. I've tried it for fun and it's like having a 4500 lbs GTP.
Or a GTP with four Fat friends in it. Having two engines actually reduces the load on each engine/transmission, especially the front. The rear engine load is closer to a normal gutted GTP.
I've crunched the numbers and analysed the weight transfer.
With the new suspension mod the load of the rear is less which is why it peels off easier but now it acts more like an powerful AWD car with wheelie bars. Yet no wheelie bars !!