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[7808]

I got a ebay tial mvs 38mm vband knock off. tried testing it to figure out what springs were what, so I rigged up a bike pump and boost gauge.  its crappy but it will make 15+ psi for short bursts before leaking (probably the bike pump nozzle) anyway

 I thought you always connect the boost line to the top port of the wg.  couldn't get it to move the valve that way. took the springs out. still didn't move. realize that im just pressurizing the top above the diaphragm so not sure how that would even move the valve up. so I try one of the 3 lower side ports this thing has (no idea why it has so many, It has a total of 5 ports. came with 3 plugs and 2 banjo barbs ) doesn't move with both or one spring in it. take them out. valve goes up/opens like it should when I pump air to it.

why does it even have the top and side port in the top hat?
why the f does it have 3 ports  in the bottom half ?
swear I remember always  hooking up a line to the top of the wastegate.. I thought the bottom ports were cause real tials have water cooling but the china knock off just is open to the bottom of the diaphram

[dvst8r]

Top port is for when you need more pressure than springs alone can provide. IE springs are good for 15psi and you want to make 30psi

3 bottom ports are just for convenience so you don't have to run a line right against a manifold.

[turbohf]

arent the MVS wastegates also water cooled?

[dvst8r]

arent the MVS wastegates also water cooled?

The tial ones are, who knows about the knock offs. I have never had a knock off mvs before.

[7808]

they may sell knocks offs that are water cooled but this one is not. looks the same but where the h2o ports are on the tial is aprently where you hook the pressure line up on these.

still not sure why even with only one spring (there is a lrger and smaller diameter black spring inside when I got it) 15+psi wont open it. with no spring the valve moves freely

I used the "lighter" feeling of the two springs too.  good thing I didn't slap it on and go for a rip.

[Tim]

look at all 3 ports on the bottom.  I remember a picture showing some of them aren't actually drilled anywhere but just a dummy port.
Make sure you have the barb going to a legit port and any other legit plug on the bottom is plugged.
Leave at least one of the ports on top open so the air the diaphragm displaces can have somewhere to go.

[HiProfile]

Sometimes they're just assembled carelessly and the diaphragm is pinched. If you put air in the correct bottom port, it will leak a little around the valve guide but none should come out the top port. The bottom port lifts the valve up to bypass exhaust, the top port forces it shut longer to keep exhaust in.

Honestly I'd feel safer with the emusa-style WG (older type replica) or the wyntonn-style gates. I've read on yellowbullet those take a beating, but it's a good idea to lap the valve & fire ring with grinding compound as well as polish the valve stem. Also check for leaks as mentioned above.

[7808]

This aint my first chinese 38mm wastegate.i took it apart diaphragm is not pinched. All bottom ports are fully drilled. Really not sure why i cant pump it open by hand with 15+ psi. I cant imagine one of the single springs it came with are made for more

[92CXyD]

This aint my first chinese 38mm wastegate.i took it apart diaphragm is not pinched. All bottom ports are fully drilled. Really not sure why i cant pump it open by hand with 15+ psi. I cant imagine one of the single springs it came with are made for more

The ports not being used on the lower section plugged off? 

[7808]

Ha. Yes i plugged them. Top ports are open. It wouldnt get up to 15psi if it was not somewhat sealed

[7808]

Welp.this wastegate definitely does not work, and im not sure why. Anyone got any ideas before i replace it?

It only has one spring installed and i hit 15psi the other day before letting off. Pretty sure only boost control i have is my foot.

The valve seems to slide freely and fits well like it was machined ok. It works with no spring, it will open with pressure to any of the lower ports. The included springs dont seem like any one of them could hold 20psi or anything

[HiProfile]

First remove the spring completely & wedge something under the diaphragm to hold the valve open. See what it does then. It shouldn't build more than a few PSI, ideally zero boost.

Next find any coil spring that's just a bit stronger than needed to push the valve closed, see if you build any boost. Might create a hair more boost than no spring.

If both go as expected, maybe the springs are just too stiff. Try to get a 4-7psi spring and see what it does.