Guys, I have developed a major boost leak over the weekend and still havent totally fixed it. On Friday my car would only boost to about 8-9 psi (normaly 15-16 psi) and all I can hear is air gushing from under the bonet and I dont know where its comming from. On first inspection I took a few pipes etc off to see what the problem was and noticed a 1 inch split at the turbo end of my turbo intake pipe. I thought great I know what the problem is then ordered one from audi. N.B. forge dont make a silicon one for the AJL engine code. Anyway changed the 'TIP' yesterday and although it improved slightly it didnt totaly solve the problem. After the change I was getting 9-10 psi with the same gushing air noise when I try pushing the throttle right down. So after that I changed my N75 to the N75J varrient just to see if it was that. It made the car much crisper at the lower rev range (1400 - 2800) and lower boost range (0 - 6 psi) as it did when the car was running fine. However the car now boosts to about 10 - 11 psi but still air is gushing out from somewhere. I have checked for visable signs of split pipes all over the engine bay and nothing appears obvious. All clamp connections also seem fine. It sounds like the gushing air maybe comming from round the airbox/turbo side of the engine bay and not the intercooler side, though I cant be 100% sure. With no obvious splits I am thinking along the lines of a faulty valve, though dont know which one. Any ideas guys? Its a bloody pain that you cant load the turbo up when the car is stationary because its differcult to check for leaks when driving. So is a proper look on a rollong road the only way to find this? Or you reckon VAG com could give me a better clue?