http://www.performancechipsdirect.com/Porsche/Boxster/
 

Can someone tell what exactly this does?,,, besides the fact seem to me be nonsense...

Its obvious:
Your convertible will be an even more exciting drive when you install a Boxster performance chip
Just like the ad says.... I bet it will even increase horpower, torque, brake performance, gas mileage, decrease gas prices, stabilize tire pressure, improve radio reception, more attractive people will ride in the car with you, red lights will all go green and the best is that it will take 5 strokes off you golf game (per nine holes)! All this and more. And if you buy now, we'll throw in the ShamWow to wash and dry your car.

Call now! Operator standing by!

Its about $2.00 worth of wire and resistors that accomplish nothing.

Appears to be a simple potentiometer

http://en.wikipedia.org/wiki/Potentiometer

This probably gets hooked up to the MAF sensor input to make the ECU lean out the mixture. It's a dangerous thing to lean out the fuel mixture across the rev and load range in general and without looking at the exhaust byproducts, you have no idea how lean it's getting, which can be bad for the life of the engine.

There's no quick and cheap solution to increased power in most cars and especially not with these Porsches. The only reasonably safe engine operational enhancements are done to the ECU (or by replacing the ECU with a tunable one) and are done while monitoring the engine's performance, timing, and mixture. A competent tuner may be able to eke out a little extra from an engine by being less conservative than Porsche was.

But this thing maybe worse than worthless, it may be dangerous.

It removes $79.99 from your wallet and transfers it to Performance Chip Direct's bank account.

:D