Hi all, I am in need of some advice please. I have recently fitted a new turbo & v3 manifold to my S3 225 and also made a 3" down pipe/decat at the same time. The problem I am having is I am under boosting up until around 4K revs and over boosting past this point. The turbo is a bit of a mismatch as I bought a turbo core from NKK turbos which has a 360 degree thrust bearing and step oil seal, and the hot/cold side was robbed from an Ebay turbo i had to buy because i had a huge crack across my wastegate and most of the hot side. I noticed the wastegate port was slightly smaller on the new hot side. There was other small defects with the new hot side such as a small spacer needed making to get the EGT sensor to tighten and seal. All flanges on the manifold and turbo are sealed 100%. MAF is good with a nice steady increase peaking at 226 g/s. N249 has been deleted. DV is a Forge 007p in good working order. I have smoke tested the entire vehicle exhaust and intake side showing no leaks, i have also visually inspected all the suspect pipe work. I have no faith in the Ebay turbo parts used after fitting them and im on the brink of buying a another K04 023 from a reputable turbo company this time, but would like a second opinion first.
Thank you in advance for any replies