Many thanks to both DuSpinnst and brentil for the GM web citations for the performance info re Ecotec. I'm rather amazed that GM is so involved in providing supercharged kits for the Ecotec. The idea of a GM warranty makes their kits "factory" as far as I'm concerned, a BIG plus.
In comparing the engines' dimensions, I find that the 2.0L (supercharged) Ecotec is a de-stroked (but builtup) version of the 2.2L (86X94.6 vs a totally square 86X86). It is more or less bulletproof with forged rods and
crankshaft (however, even the cast crank of the 2.2 is good for over 400 HP).
The Solstice Ecotec is both stroked and bored w/respect to the other versions (88X98). It is similar to the 2.2 in that crank, rods and pistons are cast.
Since the 2.2 can be supercharged to 250HP with a GM supercharger kit, the 2.4 can also easily obtain that power level (and more) with a totally stock engine.
In addition to the supercharger itself, the kit requires installing a new belt idler pulley and generator bracket and intake manifold bracket and throttle body-to-supercharger adaptor plate (all included) and a new set of larger fuel injectors. The electronic engine management needs to be reprogrammed by a GM dealer. Installing the hardware shouldn't take more than half a day's work, if that. Note that no modified intake, cat or exhaust is involved.
So the question is whether the 2.4L in the Solstice can be supercharged with the existing GM 2.2L supercharging kit. Someone said that the intake side of the engine in the Solstice/Sky is too crowded to fit the supercharger over there. Except for that issue, everthing is pretty straightforward, and simple. I wonder what the kit lists for? I have a source in a GM parts department who can get me anything with a GM part number for about
20% off. It still might be cheaper to buy the from-the-factory version, since you have to replace the injectors and that money is thereby wasted. Injectors used to cost over a $100 apiece, although that was many years ago, and they may be cheaper now.