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Knockoff Tial gates and you! Tips at bottom apply to all wastegates!
So I recently had my Tial knockoff gate poop out on me. I picked this up for about $120 shipped on ebay through a 'best offer' option. Tial themselves have said that a side-by-side comparison would fool anyone that doesn't work with Tial or where the housing are cast.
I replaced my lifters, swapped to a TBSS intake and ebay TB, went out for a driveability tune, and hit 30+ PSI (again).
I get home, take the gate apart, and the diaphragm is shot. This is, as it turns out, at no fault of the wastegate itself, but my poor reassembly the last time I changed springs. There is a small groove on the lower half of the wastegate that the lip of the diaphragm sits in. When you put the upper half of the wastegate on, it is designed to pin that diaphragm into that groove so that it can't leak or come unseats. Unfortunately, I pinched too much of the diaphragm.
So, I decided to order a new diaphragm straight from Tial for their 44mm MVR wastegate. I got it for $46 shipped to my door. Here is the packaging and part number, along with side-by-side pics of the old knockoff diaphragm.
P.S. I did measure the diaphragm dimensions with a digital caliper, and the differences between the two were, in most cases, thousandths of an inch.
It fit perfectly into the knockoff wastegate, and the springs fit perfect as well. The diaphragm fell perfectly into the groove on the housing.
Now comes the tricky part. Re-assemble.
The easiest way is to put it in a vice and SLOWLY close it up. Do NOT close it all at once, or you'll run into the problem I had before with pinching the diaphragm.
SLOWLY, begin to close the wastegate. You'll notice here that the top of the diaphragm is wider than the opening in the wastegate, which is why they get pinched. THIS APPLIES TO REAL TIAL GATES TOO, SO TAKE NOTE OF THIS WHILE REASSEMBLING AFTER YOU HAVE CHANGED SPRINGS.
When you close the wastegate up a little more, you'll see the top of the diaphragm get stuck, and the diaphragm will start to expand. The picture shows you what happens, and how it gets pinched.
You'll need to grab a flathead screwdriver, and work your way around the entire diaphragm making sure that it gets pushed back into the upper part of the wastegate to prevent it from being pinched. It will look like this;
Now tighten it up, throw the screws in, and you can continue.
Next is something that applies to ALL wastegates, and should be done EVERY time you changed anything with your vacuum system, wastegate lines, change springs, etc. IT MAY SAVE YOUR ENGINE.
I take a plastic T-fitting, and stick the wastegate line on one end, and the line going into my vacuum block on the other. My vacuum block has my boost gauge, and MAP sensor on it, as well as my BOV and water/meth pump hobbs switch. Then, I run a line from the open spot on the T fitting to a small adjustable regulator, and connect it to my air compressor. From here, I can give pressure to the regulator, and slowly increase pressure going to the vacuum block and wastegate.
Why is this such a handy thing to do? I slowly turn it up until the hobbs switch closes, and my water/meth pump comes on. Then I check my boost gauge and MAP sensor reading in HPTuners. From there I can adjust the hobbs switch until the pump comes on when I want it to. Next, I increase pressure until my wastegate is wide open, and then check the boost gauge and MAP sensor. This is a great way to make sure the wastegate is working, what the spring pressures are, to find any boost leaks in the wastegate/vacuum block system, and ADJUST YOUR MANUAL BOOST CONTROLLER. I mark mine so I know where spring pressure is, where 20 PSI is, and where 24 PSI is.
So remember these tips the next time you buy a knockoff Tial, change the springs in your authentic Tial, or any other wastegate for that matter.
A little spray silicone and a large C-Clamp also help reassembly. Esp if you have some heavy springs that are difficult to compress by hand. This lets you get the top centered and to press it down slowly perfectly straight so you don't pinch anything.
Do the tial springs work in the knock off? Were you using tial springs already? They look similar enough im going to order more spring for mine. Also need to check for leaks, everywhere . Great post op.
A little spray lube does help, but you shouldn't rely on it to do it all for you. You might still have to squeeze the diaphragm into the housing a bit, so I just went ahead and showed the entire procedure.
I use a drill press to compress mine. Keeps it square and controlled. Super fast. A little silicone spray and a small flat head to get the diaphragm to play nice and your all done in like 3 mins.
I don't have a Tial or a Tial knockoff but I do have a Wyntomn. Very tricky my first time to get the diaphragm in correctly. Ended up pretty much using the same procedure, but instead if using a screwdriver I use a fat zip tie. Stiff enough yet rounded off a bit to safely manipulate the diaphragm.
04-08-2016, 12:26 PM
Knockoff Tial gates and you! Tips at bottom apply to all wastegates! 
. Great post op. 
