Various issues with EMUSA wastegates.
 

Ok, so let me start by saying I know many people have had good luck with these gates. They're a fifth of the price of a brand name wastegate. I don't blame people for using them.

However, I have recently wasted hours and hours with these damn things. I will be getting a set of Tial gates whenever I have the funds.

Anyway, I recently bought a turbo car which had a set of these gates on it. Car was over boosting at around 14psi, then leveling out to 10psi. 6 psi springs in the gates. So, I went ahead and bought another set of gates. At only $57 a piece, I figured what the hell. I get the new gates on, and they worked great for about 10 pulls. 6psi just as the springs are rated. Then one of them stuck open. So, I pulled it off. Opened it up, and found that a bolt had backed out which was preventing the valve from closing. Tightened it down, reassembled the gate. Got it on the car, and went for a cruise. Now I was seeing in excess of 20psi off the gates! Not so bueno. Called the company I bought them from. In their defense, they were great. Sent me out a new gate the next day. Didn't even ask me to send the old one back. I received that new piece yesterday, got it installed, and the motor is now seeing around 10psi off the gates. Still too high. I have a boost controller, so I want boost off the gates as low as possible.

At any rate, I'm tired of messing with these things. To my knowledge, I've assembled them correctly - tucked the diaphragm, tightened the bolts in a star pattern, etc. I think the problem is the machining is just so damn bad..there's no getting around it.

The way I see it, you spend a ton of money on the rest of your build...may as well buy a quality wastegate. It sure seems to make a difference.

That's crazy I have 2 on my car with 2000 hard miles with no issues. I think in your case it was a fluke that the bolt came loose. you are right though most of the time you def get what you pay for.

What does your hotside look like it could be a lot to do with the direction of flow towards the gate.

I have a set of the 38mm ones. They are really not bad for the price. I pulled them both apart as soon as I got them. They both had shavings in them from not cleaning them after machining. The diaphragms are nice enough. One needs to have the stem guide honed. There were a few bolts that were tight in the threads. Also the flanges on the v bands need to be machined down so the clamps will fit on them. If you are willing to put in the work, they are well worth it. I have not finished mine yet but I plan to run them on my 1500hp top dragster build. I might be crazy but I think they can work. I plan to make upwards of 30lbs

The turbo spools really fast, and I'm pretty sure the hot side is efficient.

https://cimg5.ibsrv.net/gimg/ls1tech...56a0cd08f3.jpg

As I mentioned in the first post, they seemed to work fine initially. These are also the 38mm.

I run 2 of their 38's as well. Have about 1000 miles so far with no issues. With only one of the 2 springs installed, I only see about 5 psi, with no creep at all. I recently installed the second spring and now see about 10 psi.

Hmm, I guess I will take them off one more time and check them out.

Depends if the experienced 12 year old Asian child assembled it or you got stuck with the new guy.. (the 8 year old). It's luck of the draw!

I tear them down before I install them.

1.)Deburr the valve shaft and bushing.
2.)Make sure the valve seats well. (If not I lap by hand)
3.) Inspect diaphragm for tears.
4.) Remove the screws that hold the pressure chamber on and reinstall with red loctite.
5.) re assemble valve with high temp nickle grease.

Then I pop them off in the winter time and inspect/re-grease. Never had a failure on one I've worked on. You're basically doing everything Tial does before they ship one out the way I see it.

First time I didn't this happened! :lol:


https://cimg4.ibsrv.net/gimg/ls1tech...70ce0f0aa0.jpg

Be careful not to pinch the diaphragm. I use a large wood clamp to install, remove the tops. works really well!


https://cimg6.ibsrv.net/gimg/ls1tech...8011ffa1f6.jpg

Forcefed, I have a chinese 60mm gate right now that leaks like mad from the pressure chamber (bottom port below the diaphragm), through the "valve guide" and out the dump tube. Do you have any idea how to rectify that? I'm kind of at a loss, and think I might just have to throw this one away. Lol

Top port should be 100% sealed.

Leaking around the shaft on the bottom port is “normal” to a point. No way to get an air tight seal around the shaft. But a closely machined valve shaft and bushing is also something you get with a quality gate. Not much you can do about it if the bushing to valve shaft clearance is too large. Can pop the top off an look for a torn diaphragm. I've had a few I received this way.

This is very good advice.

Ok, that's what I was thinking too. My TiAL gates have held most of the pressure in the chamber and have moved the valve smooth as can be. My other chinese gates have held most of the pressure (and moved the valve much less smoothly). This one must be the one where my luck ran out! Haha. It was bound to happen.

I appreciate the advice man. I'll do the latter and see how they work.

So, I disassembled both gates, checked them for burrs, lubed the valve stems and put Loc Tite on every screw.

I took the car out and found it was still slightly over boosting at 10 psi off the gates while running 6 psi springs. At any rate, I got the car on the dyno Friday. I turned the controller on, which is set to 5psi over spring pressure, and on the first pull, the car saw approximately 15psi. That jived. We kept the boost the same on the second pull, but this time the car saw 20psi. We repeated this for another 4-5 pulls. It made 20psi every time. I figured i'd roll with it, however I just took the car out earlier today, and it's seeing 15psi again with the controller on.

I guess I'll just have to wait until I can afford some quality gates. I do appreciate everybody's help though.

A springs rated pressure doesn't dictate boost levels. Depending on the setup a "6lb spring" could many different boost levels. Back pressure, WG valve size, WG dome size etc... all come into play.

Unless the dome is leaking... I'm willing to bet it's your controller, not the gate. Bypass the controller and run a line straight from the turbo to the bottom of the gate.

I did figure the controller to be at fault initially. However, I conferred with the original owner, who knows the car better than anybody, and he feels it has to be the gates. '

Don't you think if there was some degree of binding in the gate somewhere, that it could act oddly when combined with the controller?

Not that I've ever seen. It's a super simple valve design. They usually work or they don't. If you opened it up and everything operating smoothly I'd go right to the controller and or plumbing.

Leaking boost into the shaft is normal operation.

A better video...