people buy the kit trying to make power, but then they never build the motor. so it ends up being unreliable. and they have a hard time tuning. a reliable tuner is a little bit of a rarity around here. the barely know what e manage is. and then when you show up with a blue e manage....they go :why the hell did you spraypaint that thing?" so boosted motor, better to build for boost. pistons, injectors, rings, rebore, bearings while everything is down, exhaust. not overly complex. timing too of course though.