not reaching peak boost/ no alky

[nolanator]

I've read quite a few past threads relating to this topic, but opinions and information vary from one to the next, so here is my story:

My car was boost fine making 23psi on the street and felt as if it were pulling hard. I took it to the dyno and all of the sudden, it was just acting up. I would start my pull in 3rd gear, slowly ramping the RPMs until 40mph and then pushing into the throttle until WOT. Immediately, my alchohol started to not come into until about 4800rpms and my boost would only reach between 12-15psi.

I thought that perhaps it was the slow progression in third gear that was causing the turbo to lag and not reach a correct boost signal to trigger the alky, but on the street the car feels sluggish and i'm still only making about 12-15 psi, although it feels much slower than what a pull at that boost should.

My vacuum lines appear to be in good condition, and nothing has really changed except for a small exhaust leak that showed up on the dyno.

The car drives wonderfully out of boost, but hates being pushed. any ideas or questions I can answer to help you help me? Thanks

 

[Lil Truck]

Where is the boost at 4800? Alky turns on with the boost its tuned for ... 10psi ?
Sounds like the waste gate may be stuck?

 

[nolanator]

Where is the boost at 4800? Alky turns on with the boost its tuned for ... 10psi ?
Sounds like the waste gate may be stuck?

Just replaced the wastegate with a new TiAl unit. The old wastegate was bench tested and works fine as well.

 

[nolanator]

I found the problem and its embarrassing. All of the studs that connect the header to the turbo had backed out and fallen so there's my leak and the reason I wasn't making power.

Still made 328whp on the dyno which is surprising.

 

[Lil Truck]

Glad you found it!