Boost/WG Leak N55 G35-900

[gengis]

I'm currently running a fully forged N55 PWG with a hybrid turbo machined to fit a G35-900 core with a PureTurbos WG.
Running JB4 + BEF (yes, I've tried to remove JB4). I have used JB4 for a long time, and I'm 100% sure that's not the issue, mainly because there is a guy in Germany doing 1000WHP on a JB4 + BEF (but he's EWG).

The log:
https://datazap.me/u/gengis/n55-hybrid-g35-900-3-gears-boost-tanking?log=0&data=1-3-4-11-19-29

Pull 2nd to 4th gear to show how, when shifting, the boost goes up again.

Tests done so far:

• I ran the smoke machine for around 30min, no leaks whatsoever smoke machine did around 3psi (in case that matters), but I'm quite sure it reached 10psi at least due to the amount of pressure released when I removed the smoke plug).
• I plugged a custom tube to the WG, it's correctly adjusted and it fully opens at around 5-6inHg, but it doesn't maintain vacuum (probably my MityVac has a broken seal or something, I'm quite reluctant to think that the brand new WG Actuator from Pure is faulty, I will test another MityVac tomorrow.

Given that there are no boost leaks, and how the log looks, I'm leaning towards a broken vacuum line or a bad solenoid.

How does the solenoid work? If the solenoid couldn't hold the vacuum or the vacuum line to the WG was blown, would the solenoid know the output vacuum and try to overcompensate that moving the WGDC to 100%? Currently, it's holding at around 80%.

Do you see anything else in the log that would lean more towards one of the theories or even another one?

Any help/ideas are welcome!
Thanks!

 

[wheela]

I'm not too familiar with jb4 logs.

Do you have any details/pics you can share on the turbo? How confident are you the machining is appropriately positioning the turbine wheel of the g35-900 core in the turbine housing? I'm not an expert, but I suspect incorrect positioning could impact your ability to build boost.

If you're using the stock boost solenoid with vacuum, you definately want to get rid of all vacuum leaks, as that will limit the ability of the wastwgate to close against back pressure. That system will NOT be able to tell you have a vacuum leak, but if boost is under target it will apply more duty cycle to hit boost target. How much more depends on how the tune is set up.

As far as vacuum leaks go, the vac system also controls the exhaust flap. If that is disconnected, make sure the associated vac lines are also capped off, or it will be a vac leak impacting your wastegate.

 

[gengis]

Turbo is not the issue. It's from HPT in Portugal, they have a rock solid background on the turbo business.
Also, I personally know 3 people running the same turbo. 2 EWG, 1 PWG.

Forgot to say this is a F30, so exhaust valve is electronically actuated. Only brake booster and WG solenoid need vacuum.

Currently using the stock solenoid because AFAIK, it's more than capable with PureTurbo's reinforced WG (If I recall correctly it's +2psi vs OEM).

About the vacuum leak, if you look at the WGDC with the boost and target in the log. You can see it's not maxing out the WDGC while not reaching the target pressure, WDGC stays there while pressure keeps dropping.
That's what triggering me, that if the turbo is thinking there's a leak, you would normally see a 99% WDGC while trying to correct it.