Thanks for the reply’s. Its hard to know what to make of different tuners/people in the know opinions on turbo’s/engine tuning ect. The tuner i use is well known and respected and im sure he’s said that there is no way a standard cossie motor can do 500 hp by just putting a borg warner turbo on as the engine cant flow enough air without having the head ported and cams changed ect. Also that in real terms a borg warner will only spool about 400rpm quicker than say a garret gt3071. Wheras i know that ma developments have shown getting 500 hp out of an internally standard motor, and swear by the response being night and day different to the garret stuff. Im not saying anyone is right or wrong or whatever, just makes it difficult to know who is right or wrong and what way to go.