Various issues with EMUSA wastegates.
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.
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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!
Be careful not to pinch the diaphragm. I use a large wood clamp to install, remove the tops. works really well!
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.
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!
Be careful not to pinch the diaphragm. I use a large wood clamp to install, remove the tops. works really well!
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.
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!
Be careful not to pinch the diaphragm. I use a large wood clamp to install, remove the tops. works really well!
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.
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.
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.
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?









