13T conversions and wastegate boost

[Bleu]

I have converted 13T turbos on a stock longblock. I currently just have the turbos set up for wastegate boost which should be ~7lbs on the stock wastegates right? Well I took the car for a first spin this week and noticed that the car pushed about 14-15psi of boost. Do you think that one of the wastegates might be stuck or the larger turbos will just make more boost on the stock wastegate? I thought a 7lb wastegate limited any turbo to 7psi. Are wastegates dynamic like that?

I thought I actually knew a lot about turbos but then this happened. The wastegates move by hand. They're hard to move, but they do move.

Any info would be great. I'm not worried about knock, but don't want to overspin one/both my turbos.

[anyonebutme]

use a mityvac to add pressure to the gates to see if they move together. Or someone installed stiffer springs in the gates or overtightened the adjustment. Mine have no problem holding 7 psi.

[sen2two]

Also, this is why they have different sized external gates. To small and you will have boost spikes like your seeing. To big and you have a mess of other problems.

[sen2two]

Overboosting is common on internal style wastegates. A lot of times the "port" on the turbine housing needs to be ported out to be able to flow more exhaust gasses to prevent this.

[anyonebutme]

Boost creep is not a problem with our TD04 turbine housings when using compressor/turbine combinations that make sense. We are dealing with basically OEM turbos here.

[Bleu]

Wasn't expecting this thread to make a come back. I haven't driven it hard enough to find out. I have serious pressure pulsing now, but I'm starting to think that its because my wastegate reference is based off of the intake manifold. Going to test it this weekend and see. I always thought I had an issue there haha

[HellBringer]

Boost creep simply does not ever occur on a TD04 setup. It sounds like one of your 'gates is stuck or there are some vacuum line plumbing issues, etc.. It shouldn't be too difficult to diagnose. If the flappers move freely when disconnected from the actuators, it's either the actuator(s) or a plumbing issue or hole/tear in one of the lines, etc..

[KeithMac]

I have come across one car where the timing was so retarded it caused mild boost creep (more like antilag).

I've never experienced it first hand and never seen anyone overrunning the stock wastegate openings.

[Chris@Rvengeperformance]

what wastegate brackets on your running on your 13Ts?

[Bleu]

Not sure where the brackets came from. I think they were a homebrew. I need to get back in the engine bay to play with some stuff but just moved. My guess is that the front actuator is too tight because its clocked wrong.

Also, the vacuum ports on top of the throttlebody; do they give a pressure signal for pre throttlebody or post throttlebody? I think that I have my vacuum reference coming from there.