Joe at FCSS has done a 2.4 conversion and remapped to about 200bhp without a turbo.
I think the engine is the same size other than being slightly taller to accommodate the slightly longer stroke. I think the bore diameters are the same.
You make it sound so easy Toby
It was wasn't it Joe? Just chuck it in, and job's a good un.... though you had to close the bonnet too, which took a bit longer
I seem to remember you junked the VIS system, put more aggressive cams on too, plus lots of remap work. Anything else like bigger injectors?
Anyway, the VIS in standard form is 155bhp (only 8bhp more than the standard 20v) and Stage 1 remap will make around 10 - 15 bhp more. I'd imagine that dropping in a 2.4 will probably cost a fair bit, just to gain the extra 15bhp over a standard VIS (the 2.4 is 170bhp with a bit extra torque) so I would think you'd be better getting a 20VT if you want a big increase in power. Especially, as the 20VT has uprated parts (suspension, clutch, gearbox, brakes) to deal with the power.
I know what you mean about the VIS. It doesn't feel that rapid, but it is lots of fun and sounds great. I would like a turbo also, but the VIS is a good all rounder and pretty reliable. But I hope to get a 20VT one day.