I've been doing some readiny up and tinkering with the Audi, I've read several articles about steps to take before upping the boost. All intakes hoses and vaccum lines have been replaced, all sensors are working properly and output codes when they're specified to.

So my question is now.. what's the max. I should boost this Audi? It's got 150,000ish miles on it. The head, head gasket, seals, pumps, etc. have all been replaced and the clutch is brand new. I recently bought a chip, pyrometer, boost gauge, and a wideband 02 sensor. I am wondering if it's safe to "bypass" or delete the frequency valve. Is one bar too far to push the turbo? What are the limits of the intercooler? I realize not many ppl modify 5000's but I would like this sedan to have some more pep! I have three springs to choose from on the wastegate which is one stock and two ones which are stiffer.

Who is most knowledgable about these engines?

 

On 150K motor without a rebuilt I would be hesitant to do any large HP gains. Reliable 225~250Hp is about the maximum that I have heard without major engine rework. Anything higher and you will need to increase your cooling, oiling, fuel delivery, bottom end, exhaust etc.