Wastegate issues with EBC

[BrokenTsi]

I'm running a tial 44 on a divided T4 manifold. I had some boost issues on the dyno last week. Boost was dropping to almost wastegate pressure (1 bar), but at the same time, my alternator died. We assumed since the alternator was dying, that the EBC wasnt working properly.

I replaced the alternator and I'm still having a bit of a boost issue.

On my Gizzmo EBC, a 70% duty cycle always ran about 30-31psi. For some reason, now I have to run 80%+ to achieve the same boost levels.

With the boost solenoid disconnected, I would get about 14 psi, about wastegate pressure. I can get boost to rise, but I really have to crank up the boost controller in order to get more boost. I have NO boost leaks.

I pulled the wastegate off, and it seems that the valve opens at 10psi. Everything SEEMED ok to me. I'm wondering if the spring is getting weak, or if there is a leak inside the wastegate that I'm just not seeing.

Should I be running a higher spring for the boost levels I run?

Whats a good way to properly test a wastegate? We did a smoke test, and nothing came out of the exhaust. My boost source is the compressor cover, and I'm using both wastegate nipples on the Tial for the EBC. I've never had an issue with boost control until just recently.

The only change I have made is going from GM MAF to speed density.

 

[ulitka]

Pressure test your WG with some soapy water. Once you pressurize the bottom port of WG to your target boost level, verify no leaks at air fittings or anywhere externaly, you will always have a leak internally through a valve guide. You should have zero leaks when you pressurize the top port of the WG.

 

[BrokenTsi]

Can I pressurize the top port with the wastegate still on the vehicle?

 

[ulitka]

Can I pressurize the top port with the wastegate still on the vehicle?

You sure can, just got to remove the boost controller hose from top WG air fitting and connect your compressed air to WG top port, give it about 15psi and check for leaks. Suspect could be air fitting washers or diaphragm or two halves of WG not seating flush, soapy water will help to detect external leaks. There should be zero leaks when pressure testing the top port of WG.

 

[slipstream808]

Is there any way to swap to another solenoid? Yours could be failing.

 

[BrokenTsi]

It bleeds off air where the diaphram is. You know how the wastegate is 2 piece? Right where they meet, it leaks. Bad diaphram?

If I apply 15-20psi, it constantly bleeds off until the air is gone. It should hold indefinitely, correct?

 

[ulitka]

It bleeds off air where the diaphram is. You know how the wastegate is 2 piece? Right where they meet, it leaks. Bad diaphram?

If I apply 15-20psi, it constantly bleeds off until the air is gone. It should hold indefinitely, correct?

If you are testing through a top port of WG, then it should not leak and it appears you found a leak. I would pull WG apart for inspection of diaphragm, perhaps diaphragm got pinched between two halves of WG during assembly. If diaphragm looks ok, check both mating halves of WG for flatnes and insure it is debry free during re-assembly, make sure all bolts are fastened in cross section pattern gradualy. If you still have issues, contact Jake at Tial for help.

 

[BrokenTsi]

Well, I havent taken it apart yet, but I was able to hold 35psi all night tonite, but I just had to run higher duty cycles than normal.

I may just go ahead and order a new diaphram for it...........its cheap enough.