Maxing out MAF/Injector symptoms?

[Sugar]

To make things simple, I have a GT2871RS. The wastegate is at 10psi (higher than had planned). Car has stock ecu, stock injectors, stock maf. This is what happens.

Car will build boost fine, but once it hits 4000rpm boost drops to 0, although the turbo will still be chugging away. The car will also run with a vac reading of 5-10psi after driving for a bit. The car did lean out, so im assuming it's maxing out the injectors/maf. But would that cause this issue? I would of assumed it was a wastegate issue but this is the 2nd turbo now.

Had no issues with the stock t25, there are no boost leaks (positive on this). I figured maxing the sensors the car would lean out and possibly get detonation. Just trying to determine if thats my problem.

[Seishuku]

I was able to max out my stock MAFS on my T25 at 12PSI, I'm 110% sure you're maxing out yours by quite a bit.

If it's a totally stock ECU, then you're most likely hitting the "boost cut", which I think cuts fuel and spark.

[Sugar]

I was just curious as to if those were the symptoms. We rewired the MAF today with shielded wire, also made a pressure tester for the wastegate to make sure it was functioning properly and it was. I

I just expected detonation or something when the car leaned out, the BOV doesn't release or anything. If a few more people could chime in then that would be great, but it does make sense. Thanks for chiming in.

[Blown240sx]

If Boost drops to 0 under full throttle Im going to say boost leak. There is nothing ECU or stock electrical related to the amount of boost you have.

[zachattack_5491]

Yeah, nothing electrical kills boost like that. If your engine is pumping at 4000rpm and you have zero boost that air is just getting lost somewhere. You're sure the wastegate isn't screwed up? And you shouldn't be maxing out the system with that setup. I guess it's possible... you're right up there at the limit but I think you have some other problem. It wouldn't cut out that hard. People that max out the fuel system melt pistons over a long period of time.

[Sugar]

This is the 2nd turbo to do this, I'm assuming both wastegates are not malfunctioning. I did make a tester to hook up to the wastegate. It stays open with constant pressure, fluctuates open and closed when pressure varys. I don't have any boost leaks, im sure of that.

The car will go to any rpm with no boost, if its under a load while at 5-10psi it will do it.

[PyR0NiAk]

And you shouldn't be maxing out the system with that setup.

Zach, I'm not trying to be a d!ck, but did you read everything before you responded? A GT2871 is going to max out the stock fuel system FAST! podj is running 740s on his 2876 and they barely keep up at full boost.

[Sugar]

So I stumbled across some people having a similar issue with there diesel trucks. It was caused by a clogged air filter... and it hit me. I'm not able to weld aluminum, so to get it running I took a section of the stock intake but we had to remove the metal coil that keeps its shape uniform. Im curious to if it's collapsing at the higher Rpms and restricting the airflow into the motor. I'll be making a more stable intake tomorrow and see if thats the issue.

My wideband is going all nuts when driving, it keeps resetting and jumping around. I'm going to find a better ground and check the power source. I won't run the car hard if it's maxing out the sensors (which wouldn't surprise me).

[PyR0NiAk]

If you don't change those injectors and get a tune, you're going to need a lot more than a section of intake. You're going to need pistons...

[Sugar]

I highly doubt it will max it out at 8 psi, but I will be monitoring the AFR's. I was trying this setup as a t25 replacement, the engine is actually being rebuilt this fall though. None the less I won't be driving it hard unless it has healthy AFR's.

[Sugar]

Well it was the intake, Im relieved and a little disappointed in myself haha. Never heard of that happening before.

Car pulls great at 10psi, AFR's at WOT are 11.5-11.9.

For anyone wondering this is the ISIS kit. The GT2871 replica. Im not sure if they are selling this turbo yet but when they do I recommend it.

[OM3GA]

Interesting