View Full Version : How can I test the wastegate after turbo clocking?

06-13-2010, 06:48 PM
So I clocked my turbo housing.

I'm about to fab up my plate and test the wastegate to ensure there's no flex/etc.

Please correct me if I'm wrong.

http://ourlewisfamily.net/gallery/../content/g1/Jasmine/normal_slave_cylinder.JPG (http://ourlewisfamily.net/gallery/../content/g1/Jasmine/slave_cylinder.JPG)

Looking at that picture there, the nipple on the turbo housing connects to the nipple on the side of the wastegate, and the nipple on top runs off somewhere else. Looking at this, I would think that the pressure builds up in the housing feeding into the side of the wastegate, and when it hits a certain amount it opens the flap on the housing & bleeds off the pressure as necessary. If i'm right, I can use a pump or something to build up pressure on the side hose and once hits it'll 'actuate' and open the side housing. The other hose feeds the turbo vsv valve (I think) and does it's thing there. I tried pumping a bit of air in there, and it just farts at me. If I pressurize the other side, it actuates the rod coming out of the end. Is this the way it should work?

joe's gt
06-13-2010, 07:13 PM
You got it Tim. If your feeding pressure to the wastegate side and the rod opens smoothly, its working correctly. Try to feed pressure metered compressed air to it. You should test it after you make your bracket to make sure everything is good.

What happens is the compressor housing builds up pressure and the spring in the wastegate is designed for a certain psi. When the pressure gets high enough in the compressor housing it compresses the spring and the rod moves and opens a flap on the turbine side (wastegate) that diverts exhaust gases so you don't over boost. The advantage of say an electronic boost controller is that it holds the air up until it reaches a designated pressure then lets it all through at once, essentially slamming the wastegate open. This allows you to build boost faster because the wastegate isn't gradually opening and bleeding off exhaust gas in the case of just the spring-rod combination w/out the EBC. It holds the wastegate close until the very last second, and then slams it open, allowing you to build boost faster because exhaust gases aren't being diverted while your building boost.

06-13-2010, 07:24 PM
Ok, so which side should I feed it air into? when I feed air into the top, it moves the rod like it should. Feeding into the other side it doesn't.

The thing is, the side is connected to the compressor housing, so I think that should work (that's the way it was connected, thats how diagrams show it should be).

06-13-2010, 11:33 PM
The one going to the TVSV, cap it before starting. The one going to the compressor, pressurize that one. If you have the downpipe off you'll be able to watch the flapper door to make sure it opens up too.

06-13-2010, 11:57 PM
Be sure not to put more than 14 psi to it... or you risk messing something up.

06-14-2010, 06:04 PM
i am sure you can just drill and tap in a hole there you need it to be for the waqstegate to be oriented thats what i would do if i were you