Had my car tuned last week remotely, was hitting 29psi the full day of tuning . Now a week later the car just doesn’t feel the same , peak is 24psi . Leak tested and found nothing , changed a few vacuum lines and the same . Most parts are new before the tune , pump , injectors , turbo . Not sure how well virtual dyno works but said 460 whp when tuned and now I’m reading 390 whp . Just drove the car 6 hrs this weekend on a trip and it runs fine but lost its pull . Anything idea ?

mods
Grimmspeed EBC

ETS intercooler piping. Home made 3.5” intake pipe

Invidia 3” downpipe

ARTEC o2 elbow 3.5” , WB sensor in elbow

test pipe 3” no cat

Trust Titanium catback exhaust 3”

CBRD front mount intercooler

Turbosmart BOV Kompact Dual-Port

Air filter PERRIN.

Gsc springs (5040)

Gsc S2 cams

Kiggly Head oil regulator

DeatschWerks DW300 320LPH Fuel Pump

AEM fuel rail , FP gauge on rail

ID 1050x injectors

FIC resistor pack

Stock fuel pressure regulator

FP exhaust manifold

New stock timing belt

DS5 Catch can 10AN open

ARP head studs 207-4203

AGT 57mm w/ MHI housing 22psi wastegate

Stock spark plugs

JDC Coil-On-Plug Ignition Systems

 

Im willing to bet if there is no boost leaks etc, then it's that AGT wastegate. Had an issue in the past with one, I'd also check the compressor wheel/shaft play while you're down there

 

I’ll look into the WG , both that and turbo are brand new with the tuning passes and long drive this weekend but it started after it sat for a few days after the tune . Spike was 30-31 with this tune now and a log shows 25psi max in 4th. Wheel feels new still

 

If there are no boost leaks, it could be the wastegate itself as AWD96 said.
Those are about the only 2 things that could have changed.

 

Are you doing your boost leak test up to the targeted 29 psi?

 

I ran it at 10 and 20 psi but it was coming out the valve cover and no joints . Didn’t want to push it in the crank case

 

If pressure was escaping from the valve cover, it is most likely not the wastegate.

When the seals in my GTX-3071R failed, it presented with the same symptoms.

I didn't have a lot of smoke (a bit at startup), but there was a fair amount of oil in the pipes after the turbo. I would have a look at those if you haven't.

After I saw that, I did a boost leak leak test after the turbo. It held as expected, which isolated the seals in the turbo as the culprit.

 

I’ll check the pipe after the turbo but the turbo is new , and nothing is tied to the valve cover all sealed off and open catch can also . Unless I’m missing something

 

My turbo only had 10k miles on it. I had a pretty bad boost leak and I suspect I over sped it.

If the seals in the turbo are bad, the pressure will enter the crankcase and in turn blow out the valve cover.

Note: I am far from an expert, just speaking from my limited experience.

 

10k miles , man that sucks bud , I’ll check it out good I appreciate it

 

Had an AGT turbo, wouldn't make boost. Put air to the wastegate and it was all jacked up. He's a very nice guy, but the wategates are just ebay/Chinese knock offs

 

Two things to note:
1. The OEM PCV prevents the crank case pressure from pressurizing the crank case.
2. You can remove the valve cover cap while boost leak testing to prevent it from being pressurized.

If your motor sees 30+ psi then you need to test it up to that pressure and show how long it can hold that pressure before it vents out.

 

Super nice guy , he’s sending me another wastegate to try actually. No pcv valve on mine with the open lines and catch can . I’m guessing it’s making it in the head area from the intake manifold to the cylinder . I’ll pressure it again at a higher boost

 

The intake manifold should never be directly connected to the valve cover. That's going to 100% pressurize your crankcase. You should cap the port at the intake manifold. Then have all the lines from the valve cover run to the catch can. The catch can should also be vented.

 

This is right. If you are going to have the intake manifold hooked to the valve cover, you need a valve there. Stock PCV or an aftermarket 1 way, something.

I personally have the stock PCV to a sealed catch can to the intake manifold but in theory you could do with intake manifold sealed off? There is a huge thread somewhere here that discusses and tests a bunch of catch can routing options.