well before this i had this few hair line cracks at the flapper port which , is slow to hit full boost and its really slow . so change to a another turbo twin fin , and also had a small crack at the flapper port too , but doesnt look that bad as my previous one , after a few months driving it , performance starts to degrade , so now suspecting the studs & the crack at the flapper cause the fumes is really strong , confrim there is a leak in the engine bay , so best way is to sell the engine off which im doing it very soon . give up playing cars already :P .