citroen c1 1.0 12v

Hello guys,I have in mind to prepare for a c1 but there is a problem because the gas sucked in I don't know how to do the electronic part,whereas I have never done rimappature etc on the net I saw that they sell units additional from 80 to 250 euro, guaranteeing a gain of 35% on the cavalry but I do not trust,at this point I ask you is it feasible to remap this car?that gains would I have?how to spend it to buy any equipment?Thanks.
Ps:if it is possible we would add a bmc air filter cda, and collectors without the cat by inserting a 100 cells in the central part of the exhaust.

you agree, on a naturally aspirated max 10% if it is a good one

thanks for the replies,I would like to buy the equipment and me alone with the advice of the forum....I have found that until a few years ago was the c1 cup, the changes were exhaust with 100-cell air filter bmc cda bevel gear and the ecu mapped came to the 85 hp of the chassis were fitted trim and wider tires...what should I equip to map?