I had no prior mods. I installed a 2 1/2 exhaust with the kit, and a air filter with maf adapter off ebay (you can see it in my youtube video). At 6 lbs of boost the car is great. Noticable power difference, and I've had the kit for a year with no problems. If you are really hard on it you will definitly need a stronger clutch, but if it's a daily driver with some track time the stock one will be ok (it's what I am running now). If you turn the boost up past 10 lbs you will need to do something about fuel management. At 6 lbs stock ecu/injectors/maf work fine. It came with two secondary injectors which I haven't used until now. I am trying to turn boost up so I am thinking on using some dsm tricks to fool the ecu into thinking it's getting less air and then using the secondary injectors to make up the difference.