my mate and I were playing around with his engine analyser on the weekend, and one of the tricks it does is kill the spark for each cylinder in turn and show you how much power (in terms of RPM at idle) each cylinder is making. The graph it shows makes it really obvious how little work the inner cylinders do - cylinders 1 and 4 do a bit over 30% of the work, and cylinders 2 & 3 do a bit under 20% (it's particularly noticeable with twin carbs... )
the reason our engines behave this way is because the cylinders fire in pairs, we all know the firing is 1,3,4,2, but extend it out, and it becomes 2 - 1 then 3 - 4. The air flow for 3 & 4 stops while 2 & 1 are being fed, then the air flow for 1 & 2 stops while 3 & 4 are being fed.... so when 2 and 3 start to suck in mixture, the air needs to accelerate into the port, but when 1 and 4 start to suck in mixture, the air is already flowing.... hence 1 and 4 get more fuel, run richer, and make more of the power
that's on an NA car....
you've got forced induction, so I bet what's happening for you is that there is boost being built up in the inlet ports, and there might be fuel forming big droplets - so when 2 & 3 open their valves to suck in mixture, there's a sudden rush, and those 2 get a heap of juice, but when 3 & 4 open up, they get clean charge from the turbo
just my brain dump

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