what does an Ignition coil do?

http://www.howellautomotive.com/Howell/Store/catalog/catalog/product_info.php?cPath=142_38_144&products_id=671

i want to know wat it does.. and is it good to change it in my car.. mine is 1997 GS (n/t)... will this increase the reliability of the car? i also read that top end acceleration increases and is smoother a bit. does anyone have any idea wat it is and will it do any good?

I think the coils fail w/ age. If anything the car will fire better and run smoother. It might increase your performance if your coil is old and misfiring. My car has 106k on it so I'm thinking of ordering this one:

http://www.modernperformance.com/dcx/msd_coil.shtml

It will definately look better than the stock black one, too.

http://www.2carpros.com/topics/coil.htm

read the answer to the 90 thunderbird question