Boost issues (low boost)

[l1ttle_d3vil]

Getting the KE25 ready for the Night Drags in November but seem to be having a problem with the boost. Should be running 7psi on low boost (factory actuator boost) and 12psi on high boost (via Link Boost Control Solenoid). The boost has recently been running lower than it should be, 4 or 5psi on low boost and 8 or 9psi on high boost.

Initially thought it was from a leak from the exhaust manifold, fixed that, still the same. Then realised the actuator bracket flexed slightly when the wastegate opened so made a new one, still the same. Now I've tried disconnecting the vacuum line running to the actuator and taking it for a drive (in theory the wastegate shouldn't open and it should be free boosting, correct me if I'm wrong!?) and it still only hits 9 or 10psi when the turbo normally has no problem hitting upwards of 18psi... What am I missing?

Turbo starting to crap itself? Still sounds healthy, there is a small amount of oil in the intake housing but I've seen a lot worse...

Leak on the intake system? I have checked all the hose clamps and they're tight, although I haven't pressure tested it. I imagine it would need to be a fairly massive leak to only create 9psi, wouldn't it?

Anything else??

[iOnic]

Wastegate might not be closing completely/properly. Disconnect actuator arm and check for free (and full) travel. Otherwise, pressure test from the compressor inlet and if that's fine - start looking at the turbo.

[CAMB01]

Sounds like the wastegate is open to me.

[AE25]

does it feel as powerful as before?
sure your boost gauge is reading correctly? got leak in boost gauge hose?

cracked wastegate seat? although should still see higher boost up in the revs.
has the wastegate got preload on it? shouldn't be able to pull the flap arm away too easily. ie to put the wastegate rod back on the lever, would need to pull on the wastegate actuator rod to get it on.

got a cat converter installed? is it melted or blocked? doing skids can melt the guts into a blob. blocked exhaust will reduce flow and top end turbine speed. like a std 3tgte heh.

can you mount a camera on your roof pointing forwards, go for a boost with the bonnet off and post the vid online. cheers. that'd be cool to watch. nothing to do with finding boost leaks.

[l1ttle_d3vil]

does it feel as powerful as before?
nah, definitely down on power. Not much fun to drive at all, amazing how much difference 3 or 4psi makes!

sure your boost gauge is reading correctly? got leak in boost gauge hose?
as above, hardly even breaks traction anymore...

cracked wastegate seat? although should still see higher boost up in the revs.
did think about that lastnight, will pull the dump pipe off and check it out.

has the wastegate got preload on it? shouldn't be able to pull the flap arm away too easily. ie to put the wastegate rod back on the lever, would need to pull on the wastegate actuator rod to get it on.
yep, have to pull the actuator rod out about 5 or 10mm to get it onto the wastegate arm.

got a cat converter installed? is it melted or blocked? doing skids can melt the guts into a blob. blocked exhaust will reduce flow and top end turbine speed. like a std 3tgte heh.
nah nothing like that, just a 2.5" exhaust straight through to a muffler on the back.

can you mount a camera on your roof pointing forwards, go for a boost with the bonnet off and post the vid online. cheers. that'd be cool to watch. nothing to do with finding boost leaks.
haha can do, need to get a suction cup for my camera... although my engine bay isn't all that pretty!

fairly certain the wastegate is closed properly, as when I disconnect the actuator arm it comes right back and I can hear it clamp on to the exhaust housing. Will pull the dump pipe off to double check it though.

Also going to sort out a pressure test on the intake system, probably test from the intake manifold back towards the turbo.

If it is the turbo failing, what is the likely cause? Bearings failing / seizing? Dirty oil etc? Haven't actually checked how free the turbine spins... will check that out too

[l1ttle_d3vil]

So turns out tight hose clamps won't make up for holes in the joiners...

Did a pressure test on the intake, and on closer inspection found this...

Also think my BOV is leaking air even at very low pressure, so will tighten the spring up a bit...

Is there in harm in having it too tight, as long as it vents went the throttle closes?

[iOnic]

Having it too tight will make it slower to respond but no big deal. Might get a slight flutter from the turbo before it vents, that's about it.