Ah finally some new informations. makes a change from @ringo doodling on pictures ( just a joke ! )
This seems like a fundamental but straightforward problem, whether they can fix it in time who knows - McLaren were pretty poor when it came to exhaust work last year, so this is not a good sign.
Did the car manage to set any fast laps with the originally planned configuration, maybe that would give some small indication as to pace...
But in regards to this " they need to change their side pods, they're doing it wrong!! " and " why don;t they move the enging, thats a much better idea" Don't you think they've thought about which solution to go for?! I mean granted there's alot of bright people on this forum, but I'd imagine there are some in McLaren that work full time on designing the car.
They designed the car to be fast and on the way they must've explored and investigated many different solutions i.e the FEE. At the end of the day the reason the car isnt fast is not really due to their philosophy, but due to an unforeseen problem with the technical parts of the car.
In regards to how long it will take to get it fixed... Surely if they were intending to test a few different versions of exhaust system, there must be marginal differences in performance.. If one was far superior surely they'd have just gone with it to begin with, and only tested that?