wastegate test

[scottsee]

how do you test your wastegate to see if its working properlly?

[bmoreboy52]

take it off and you'll find out if your turbo is running properly lol a lot of boost baby!!

[joemathews]

If you cannot adjust boost with a boost controller, you might have a malfunctioning wastegate. If you can control it with your mbc, then your wastegate is working fine.

[dsmodder]

if you run an external wg on a turbo with an internal... you just hook the vac lines to the external? or do you weld shut the flapper also?

[guitarXgeek]

Originally Posted by dsmodder

if you run an external wg on a turbo with an internal... you just hook the vac lines to the external? or do you weld shut the flapper also?

It depends on where you mount the external gate. If you mount the gate on the manifold, then the stock internal flapper must be tac welded shut (tac'd so you can un-do everything if you decide to go back to internal). If the external gate is off the o2 housing, then the stock flapper needs to be taken completely off and that small wastegate hole should be ported as much as possible to ensure good boost control from the external gate sitting right behind it.

As for testing the wastegate, I guess it depends on what your problem is. I'm going to assume that you're over-boosting since that's what the wastegate's function is used to control. Try taking your boost controller out of the equation. Just run a vacuum line straight from the intake manifold to the wastegate actuator. This should tell you exactly what's up with wastegate actuator. If you're still over-boosting with the vacuum source going straight to the actuator, then your actuator is most likely dead. In fact, this happened to me not too long ago on my t25. I just bought a used t25 actuator and all was good again.

[kjewer1]

A simple test if you have a compressor is to just hook it up to the WGA and put ~15 psi on it. It should open fully. Try lower pressure levels too and see how it responds. They have a rubber diaphram inside, so like every other part with a diaphram it can fail eventually.