Turbonator and Tornado

I have a N/A Supra MKIV and I wanted to get some more power out of my car I have heard of the turbonator and tornado so called "superchargers", do they really work or is it just a scam? If it is, is there any alternatives to get more HP for my NA Supra and at a reasonable price?

SCAM...... you can put it in if it makes you feel better but you could also give me the money and I'll put it to good use, you wouldn't even notice the difference. The cheapest power adder is going to be nitrous, but you better have some kind of clue what your doing, or find someone who does, install it.