I just rebuilt my motor like a month ago. I drove about 500 miles, changed the oil everything looked good, drove another 1500 before I actually got on it. Realized I had no boost after 6k! .___.
Has anyone experienced or have any idea what I can do? I already took nipple off for wastegate and same thing, swapped turbo out same thing, checked exhaust manifold no cracks, did a boost leak test found a leak on throttle body elbow fixing that soon, but if that doesn't fix it what else should I check?

 

is the wastegate ported or modified?

have a catalytic converter on the car still?

 

What was the boost before it dropped to 6PSI?

 

Nope, all stock turbo and no cat

 

6psi all the way till 6k rpm then drops slowly down

 

down to what and by what RPM? need figures, the stock boost gauge isn't very informative.

 

The S5 FC should see higher boost than 6PSI.
Wastegate dashpot working properly and rod connected?

 

Turbo is fine I've checked wastegate everything it boost great at low end once I hit 6k it stops. I got a fuel cut denfenser still didn't work. I'm going to try a manual boost controller than see what happens .-.