Geez, when will folks who don't know the correct answer, stop with inaccurate information?
There is a Vortec style supercharger kit for the Fiero
The supercharger kit adds 80 hp. So you end up with 220hp
The kit can be bought here: http://www.z-spec.com/fiero.htm
It does require you to remove the A/C compressor.
Comp Cams has a stage II cam that works well with the z-spec supercharger. Ross makes pistons if you want to increase boost even higher. The Z-spec kit works very well with the stock 8.9:1 ratio. With the cam swap, porting heads and some decent exhaust manifolds like the Fiero Stores Sprint performance manifolds you can get about 250hp out of it. If you want an intercooler, Fiero Warehouse makes scooped panels that go just behind the doors and the passenger side is large enough for a medium sized intercooler.
Fageol makes a roots type supercharger for the 60* V-6's with cast iron heads (like the Fiero 2.8L) but you need to either convert to carb or TBI. The Fageol does not make a kit specifically for the Fiero, But if look on the parts list you can get all the parts required. The kits they sell are mostly for the S-10/S-15 pickup trucks. You could buy a truck kit for the correct induction (carb or TBI) then just get the thin cogged belt pulleys. The thin cogged belts come in 5psi, 7psi, and 9psi. If you want to go to the 12 psi, It requires a thicker pulley so you need to notch the cradle by about an inch and strengthen the notched area. 9psi will get you around 220-225 hp on a stock block. You will also need to add a scoop or bulge to the decklid as the overall height is about 1.5" taller than the decklid. Website: http://www.fageolsuperchargers.com/
There are plenty of aftermarket parts you can add on as well. Trueleo makes an excellent intake that flows 60% better than stock and they have a matching set of headers, ( www.trueleo.com
) Comp Cams make 4 different stage cams, Ross pistons makes forged pistons for various compression ratio's and over-bores, GM makes a stroker kit to go up to a 3.1L, The Fiero Store sells stainless steel valves with a better flow design, and most other parts can be bought thru Summitt Racing or Jegs.
Finally if you wish to make your own kit, Here is a website link that shows how to do it yourself: http://www.fierosound.com/supercharger/supercharger.htm
Good luck on your project.