Are there after-market superchargers or turbochargers available?
Most engines on stock internals, i.e. pistons, rods, etc. can only handle about 5-6 PSI of boost from a turbo or supercharger.
RSM Racing currently has supercharger kits that are complete for all 2.2L, 2.4L, and 2.2L Ecotec motors. They are a centrifugal type. Price varies with options and engine type.
GM/Magnusson has a roots-type supercharger kit for the 2000-02 2.4L engines, available through GM Performance Parts. It is a complete bolt-on supercharger kit, including a PCM reflash and 2-bar MAP sensor to handle the 5-6 lbs of boost.
A "kit" is a relative term. Some "kits" don't include everything you should be putting on your car, and some kits aren't bolt-on. There are a couple manufacturers out there for turbo kits, the websites of which are listed below:
Twistec:
http://www.twistecproducts.com
Hahn:
http://www.hahnracecraft.com
Part of the problem with adding a turbo/supercharger onto the LD9 engine is that it would require recalibration to get the timing right. It would also force you to reprogram the computer for the higher compression ratio, and to compensate for the lean burning condition (too much air) by adding more fuel into the cylinder. Additionally, turbos and superchargers can cause enough pressure in the cylinders to cause the pistons, valves, bearings, or other internal components to explode or damage themselves badly.
The Sunbird GT 2.0L Turbo engines were notoriously bad for head gasket leaks, turbo failures, and other such problems, even after only 20,000-30,000 miles. Required mainainance on this engine is high. That's why GM discontinued the engine.
