Found this quite interesting in how zee germans are trying to minimise lag through clever manifold design in the new V8 twin turbo engine used in the X6 M

Link

clever stuff, just wish they would explane it in laman terms

If I have read it right, the double R-R + L-L mean two cylinders fire at once, giving the turbo twice as much gas as just one cylinder firing meaning that the turbo will be forced to spin earlier, thus giving less lag.

They fire in succession on the same turbo, so the exhaust burbling sound happens at the turbo as well, this pulsing effect is supposed to improve run-up of the turbo. In some ways I can see how it helps, in other ways the average flow is going to be the same, so whilst it may help, I can't see it doing much.