Put the induction kit back on this afternoon and the results were surprising if nothing else.
There is a better cold air feed in place now,though it only runs from the exisiting supply minus the rubber air box nozzle thing, but right up to the 57i. I haven't reset the ECU either or done the crankcase breather mod thing.
1) It makes more noise.
2) The flatspot at around 2k revs seems to have gone.
3) My exhaust sounds a lot more rattly, as in busted.
4) Driveability is about the same, few hops of the kangaroo if using the gear to decelerate now and then.
5) No brutal juddering at 20mph in 4th gear.
Think that's it, testing continues this evening, luckily it's quite chilly out.
Not sure if I'll keepit on there yet.