The beauty of aftermarket kits (like KLEEMANN) is that they are bolt-on kits with everything supplied for trouble-free installation. That's fine if you want to go custom but there's a lot more to it than just sourcing a blower. KLEEMANN sold hundreds of kits for a reason. Their R&D meant you were getting an out of the box solution that just worked. After all you want to enjoy driving a car with all new power, not spend time and money constantly trying to adjust fueling, cooling or worrying that your engine might detonate from all that added boost. Pre-ME2.8 ECU are a pain to tune and supplying fuel to now 80-100HP stronger engine is another issue, hence the secondary fuel pumps in these setups. There's also a reason there are not many swapped-55k cars running around. If it was easy or cheap or even made sense, everybody would do it.