I am having a problem holding boost. I have a 12lbs spring in my tial wastegate. I have a k27hf. I have about 30,000 on the turbo.
When I hit it in 1st it will go to about 10lbs and fall off to 9 by redline. Same in second. When I get into 3rd it will slowly climb to 12lbs and stay there.
I cant find any leaks anywhere. Motor runs great. No smoke on start up or under boost. No oil in intercooler. Can a turbo go bad and show no signs of burning oil or leaking oil? I am going to get a smoke test to see if maybe I have a leak in intake manifold or intercooler. It is driving me crazy. I had the car sitting while the motor was built a couple of years ago but worked fine when I got the car back. Thanks John.

 

It's common not to see full boost in lower gears - the engine does not generally see enough load in the first couple of gears to produce maximum boost. I'm not sure about the 4-speed 930, but my 964 and all previous turbocharged cars I've owned have been the same; either going to a lower level in the first few gears, or reaching peak boost for an instant and then dropping off sharply. 3rd and 4th gear tend to show maximum boost figures as they're closer to a 1:1 gearing on most gearboxes, and hence work the engine harder.

 

thanks