I'm getting ready to begin modifying my 03 cobra.  I want to change out the stock blower pulley with a smaller one, perhaps the 2.8"  Will this require any computer adjustments?  Since this will generate more heat - working the supercharger harder, should I change out the heat exchanger?  Would I be safer with a pulley size in between the stock size and the 2.8"?  Any advice will be greatly appreciated.  

You'll definitly need to tune the ECU again... you've got to ballance the air/fuel ratio for the new additional air that your pulley update will give you.  Find a reputable tuner in your area, really really really check into the shop before you hand over the keys.... Your OE heat exchanger should be fine...   So will the engine with the new pulley, just make sure your A/F is right.  

OK,thanks for the advice.
I will do my homework on local shops in my area. - If anyone has any experience with speedshops in the Cincinnati area - please let me know.