So you had it properly flow tested and made sure its up to the task by a professional?
Because they wear out and their flow rate slows down meaning they run the car but under full load they don't supply enough fuel, which leans the engine out and the bearings get hammered and you get a death knock
If you come off the horsley dr onto ferris rd you drive down the hill to a roundabout turn right at that roundabout and it will come to a 90° right hand bend. There is a good area just after the bend
Edit: It's called chandos rd at the roundabout and changes to trivet st at the bend
im not saying a stock looking one can't be made faster then a stock one, But a stock one isn't a slow car either and I don't know anyone who would look at a Gtr and say "look at this piece of shit, it's got no hope" their reputation is just to great