well he's been criticized a lot of his turbo, then again he is learning about it so it's very understandable. (like i said, poor man pays more. considered paying "school fees" like i've done my share coming into motorsports. very hefty ones if i may add)
do take note that his manifold cracking isn't his only problems ever since he turbo

you do hear a LOT of BOT woes after people doing it, no? higher maintenance etc.
bolt ons are basically doing something that the car was never meant to do. (compared to cars that already come with turbos such as volkswagen cars, pug 408 etc)
to do it proper most people will strengthen their engine mounts, replace better seals/gaskets, even replace pistons or cam/crank shafts etc
it's not *just* the bolt on turbo and asal boleh PSSSHHHH sudahlah (one of the reason i never BOT'ed my car although it is ALWAYS TEMPTING me to no end)
For the money spent on BOT, it's like a hole that never fill up. car go in and out workshop like go toilet to pee...that's why I would prefer to have 1 NA car then another turbo car. NA has much less that can go wrong on a daily basis....If you want to drive a turbo car on daily basis best is to get those that comes with a turbo...but even that sometimes the factory turbo also give you black face sometimes...