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Turbo smart genV wg45 leaking?

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A lil back ground...

N54 closed deck, cut ring head gasket, ns300l certs 11mm studs throughout, ported head still stock cams and springs, di delete, syvecs s7plus engine management. Stick shift awd car.

Turbo- xona rotor 11569s 1.03ar

Started off with a 7 psi spring running two 3port mac valves at 22hz in a phase and antiphase configuration. Eventually got that boosting to 35psi gauge pressure.

Didn't really help with the lag i didn't need 7psi of boost anyway so i put 21psi of spring in it. Still only 35 psi:/

Hooked up a leak down tester to nc port and a presure gauge to the no port and tested different duty cycles with different input pressure and decided to set 34hz because the pressure output was more stable. Same 35psi max.

Next up single 3port mac boost reference bottom port. Mac to the top. Same 35psi max

Weird thing is duty cycle under 60percent at 34 psi on all configurations. And everything from there up to 100 wgdc is 35psi.

Naturally i pulled the wg and everything seems good fire ring seals no visible exhaust leaks on vband.

Put it back on the car and pluged the bottom port and besides overshooting at boost onset(aggressive pid) same results

Put the leak down tester to the top port and it holds up to 30psi sometimes for 5 seconds some times it instantly looses pressure out of the bottom port.

Is that normal operation or could that be the reason iam not getting past 35 psi and the duty cycle isnt having any effect north of 60percent?

I'm not a "turbo'" chap, so this may be from my nether regions, but it sounds like there's a problem with the sender and/or gauge - some have a maximum reading value around what you're seeing, regardless of what it actually is. I'd check you have a sender/gauge/software setting that doesn't have that limit and can read to 5 or 6 bar (absolute), as it would seem you should be seeing higher than what you see?

You could go "old school", and temp' hook up a simple pressure hose to an analogue pressure gauge, to double check if there is an actual limit to the manifold pressure, or if it's just not being read correctly.

My slope on a 5 bar absolute map is true and the voltage at the ecu is correct. I read baro from key on and thats reading off my map sensor as well and is right. I presure tested the system to 48 psi before my intake plug blew out to check for boost leaks and while i was at it i verified the sensor is calibrated. Its within .1 psi

As far as limits im no where near them and if i do hit any it will show up in a log as ign or fuel reduction and with the source from where the limit comes from.

Your test without the bottom WG port hooked up is a good one, assuming you were still feeding pressure to a top port. I would also confirm there isn't a leak in the top side of the wastegate.

If there are no leaks, it sounds like there's a good chance exhaust backpressure is high enough to blow the wastegate open. Remember while you're applying pressure to keep the wastegate shut, exhaust pressure is pushing in the opposite direction.

I would investigate that before trying to make more boost, as figuring out how to keep the gate shut during extreme exhaust pressure generally does not lead to significant power increase, only extreme heat and potential component damage.

This may be a situation where you need a larger A/R turbine housing to achieve your goals, or perhaps there's another significant restriction between engine and turbine inlet causing high exhaust pressure.

If you haven't run an exhaust pressure sensor before, you generally want to use it remote mounted, fed via coiled tube or similar to dissipate heat, and put it post a chamber like this which reduces violent pulses, to help keep your sensor safe. Here's an example kit of parts minus the sensor to give an idea:


If nothing else is wrong, chances are you'll find a great deal of exhaust pressure when you take readings.

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