What exactly does a chip do?

[TPSidders@aol.com]

I have an 86 5000csqt with 100k, I think the car is somewhat quick the way it
sits,  but I really want it to scream. I posted an ad looking for a used chip
and spring for the wastegate on a different Audi NG and a fellow enthusiast
informed me of a way to bypass the fuel cutoff. My question is if I do this
and add a different (stiffer) spring to the WG without the chip will I harm
the car ? To my knowledge the chip is designed to remap the computer and to
advance the ignition. Is it possible to just increase the spring tension w/o
the chip? If I need both to complete the task, does anyone have 
any used items for sale?
                                                                      Thanks
for the help!
														TPS