hks wg leaking problem

[400awhpgsx]

Well I've search around a little and I've called HKS and a few local shops in my area regaurding this question and I haven't gotten too much help. Hopefully you guys can give me some insight.

I have a 2g gsx with a garret pte 50 trim with all the supporting mods and then some. I have been experiencing some major lag issuses and my first thought was boost leak. I recently had my car on the dyno and my results were less than exciting. I hit 10psi around 5400rpms and 20psi around 7400rpms. Most 50 trims hit full boost around 4000rpms. So we set out to find my problem.

After doing a full boost leak test, I found that my throttle body shaft was leaking some. I did some searching and found this is a common problem and probably not the sole culprit to why I have so much lag, but possibly part of the problem. After hearing no more leaks we moved on to the waste gate. I have a 40mm HKS external waste gate. At idle I can feel some air coming from my dump tube as well as at open throttle. I've never taken a waste gate apart before, but I was told that they were pretty simple. After examining the waste gate as it was sitting in pieces on my kitchen table I found a couple things that I question weather they are the problem or not. So here we go. (I've decided to link the pictures instead of size them down, because I feel that high resolution pics are necissary)

This first picture is what the wg looked like after I took out the spring. The bolt and washer were sitting off the bolt. At first I thought this was the problem, but I realized that the spring would have held the valve shut anyways, so the fact that the bolt wasn't on there is not as big of deal as I thought.
http://i9.photobucket.com/albums/a98/mrbrianf20/IMG_0008.jpg

This next picture is of the bottom of the valve. I am questioning weather the valve should fill up the whole hole or if there is supposed to be a small gap around it. It seems that some exhaust would be able to flow right past the valve even when it is under no pressure.
http://i9.photobucket.com/albums/a98/mrbrianf20/IMG_0001.jpg

This third picture shows the top part of the waste gate again. I noticed that the hole in the center of the metal cup looks to be partially threaded. I cannot tell if the bolt that sticks through it was ever meant to be threaded through the bottom of the metal cup or if it was designed to just poke through and be tightened with the bolt and washer.
http://i9.photobucket.com/albums/a98/mrbrianf20/IMG_0003.jpg

Thanks in advance for any insight you may have.

 

[kenamond]

What does that valve seat against? Is the seat on the exhaust mani? I'm not sure about that model, but does the WG open by pushing the valve toward the mani or pulling it away?

 

[twicks69]

First off, your wastegate is definitely not working properly because of several things:

1: You are missing the valve sealing ring (the metal ring that is supposed to be between the flange and the valve -- it is molded into a separate flange that gets bolted between the wastegate and the gasket to the manifold.

2: Your wastegate diaphram looks melted and/or damaged.

3: When you pull it apart, and there are nuts/washers just "hanging around" inside, it is time to either replace all the parts or pick up a new wastegate.


I have attached a picture of what your wastegate should have had with it when it was new: You will see the valve sealing ring what I am talking about.

HK$ wants $105.00 for the replacement wastegate diaphram, $9.00 for the outlet gasket, and $7.00 for the "triangle" gasket.


Personally, you would be better off using a TiAL 44mm V-Band Wastegate. It doesn't need gaskets, uses good V-Band clamps for easy installation and clocking of the wastegate and dump tube, and has a wide variety of spring rates available.

Good luck!