1957 Beetle, 1990 diesel Jetta, 1990 Corrado, 2005 GTI, 2007 GTI, 2012 Jetta TDI
07 MK5 GTI 137k miles. Previously tuned by someone else through Boost Dynamic Tuning. Looks like the stock turbo/wastegate. Bought the car for $500. Sorted through a lot of problems. I’m a new VCDS user. Boost gauge reads about 20psi regularly. Once the car is nice and warm it will spike to 20 or so then fall to 5ish. Gives a p2099. Replaced the N75. No change. Original manifold (hot side) was cracked. I replaced it. New manifold wastegate is nice and tight. Preload seems fine. I suspected the wastegate actuator. When I add some pressure with a hand pump (5-10) it does move but it doesn’t hold for more than a second. Doesn’t hold a vacuum well either. If I go for an aftermarket setup with a stronger spring do I have to re-tune? Should I just replace it with a stock 5psi actuator?Looking at a turbosmart IWG75. They make one for the Audi k03, should be the same turbo as the FSI/BPY. Trying to stay away from the forge - same as the Chinese mamba on eBay. For the roasters - I did some searches but didn’t find much. Thoughts?