PaoPee wrote:is a bad thing to get power and no ecu?
So, I think you need to understand exactly how a car works so you can understand what is required for you to destroy your car completely.
Any upgrade which increases capacity, density of intake charge, increases fueling requirements or requires changing ignition parameters will require tweaking the factory tune of the car. As we all know, the MX5 ECU is not chippable or crackable so the only solutions are piggy back ECU's or standalone ECUs. These are fully programmable units that allow custom tailoring of the fuel, ignition and boost parameters so the car will run properly without destroying itself. If you think you can add a blower and not consider an ECU upgrade you should probably start digging a hole and putting $50 notes in it.
Once you have upgraded the engines performance, other things which were not designed for higher levels of power will break. So you then need to update them. These include the clutch and for better power delivery an LSD. But most importantly, you will need to increase the cooling capacity of your engine by upgrading the radiator, adding oil coolers and maybe even extra water pumps.
So, if the turbo kit costs you $8k, factor in another $8k to do it properly otherwise you might just be better off going and purchasing a V8 commonwhore.