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Dual Wastegate How To?

Old 05-17-2004, 02:02 AM
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Ok so my wastegate has been giving me all kinds of problems basicly it is far to small for my turbo. I really cant afford to get a nice big tial wastegate right now and no one has come forth with a used one any where. My current wastegate is a turboneticks delta gate mark II. You can buy these used on ebay for under 100 bucks. Now i'v heard of people running dual wastegate setups. So what woudl it take for me to get another one and just run 2. That would give me a total of 70mm for under 200 bucks were a 46 mm tial is goin to run me well over 550 bucks. That with the manifold mods. So what do you guys think? And how can i do that?
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Old 05-17-2004, 05:26 AM
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You would spend more money redoing your manifold to make dual wastegates work.
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Old 05-17-2004, 05:27 AM
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almost forgot...



*waves magic moderator wand*



*POOF*...to the single turbo section
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Old 05-17-2004, 07:25 AM
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First, my personal experience makes me not care much for the deltagate or racegate. My racegate was always having diaphragm problems (probably heat induced), and was in to breaking the shaft sometimes as well (then it doesn't close all the way).

Getting two wastegates to work in tandem takes a little doing, and you are always subject to problems such as one of them gettin hotter than the other, which softens the spring and makes it open early.

Yes, it can be done - I have a pair of wastegates on my divided manifold setup, but it took alot of work to make it run right.

And, as a previous poster mentioned, there's the fabrication work.
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Old 05-17-2004, 12:46 PM
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I allready was quoted 100 dollars for the fab work. I have a buddy that owns a local speed shop and he's the bomb with a tig welder. He still priced me at 425 bucks for a 46mm tial wastegate thou.
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Old 05-18-2004, 08:21 AM
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Here's what I did to sort of match up my wastegates initially:



-Block off the outlet of one wastegate - note that mine don't tie back into the exhaust. I can hear them open quite clearly



-In 4th or 5th gear, gently lay into the throttle and let the boost rise slowly until you hear the wastegate open.



-Do the same for the other wastegate



-Adjust one or the other until they are as close as you can get them



I will point out that you can still have problems with one wastegate spring getting hotter than the other, changing its response. Then you typically get one gate opening too soon, slowing boost response as it slow creeps up to where gate #2 opens.

Also if the gates are different types (mine initially where), you can sometimes get less than desirable response.



I would recommend just biting the bullet and getting one large wastegate. Having said that, I will describe my dual setup:



I have a homemade divided exhaust manifold, with one gate on each runner. First of all, the gates have smallish actuators. Because of this, they are greatly influenced by exhaust pressure.

Also I was having problems syncing the wastegates as described above.

These two problems lead me to my design. I don't use any boost air at all to open the wastegates, like you normally would. They are open solely by exhaust pressure. To get around the problem of consistent spring tension between the two, I used the lightest springs and instead rely on air pressure to hold the actuators closed. That way, if they get a little off it doesn't really matter.

I use an electronic boost controller the control air to the wastegates, and it's a fairly tricky thing to set up just right.
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Old 05-19-2004, 08:38 PM
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I have 2 38mm wastgates on my manifold and they are awesome. I have a turbonetics one and a tial. To sync them up, the tial had a 1 bar spring, and the turbonetics had a 5 psi, but I can adjust it. So I hooked it up to a known pressure source (hooked it up to the Tial since I cant boost lower than 14.7 on it and turned the pressure up until it barely started to open), then I hooked it up to the turbonetics and adjusted it. I have tested these things alot and they open at the same pressure, even on the car while its boosting.



It is a crazy setup to design, but its easier to do when you build the manifold and DP to accomidate these wastegates.
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Old 05-20-2004, 05:14 PM
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It would help to know what kind of exh. manifold you're using . the fabrication and welding work is the hardest part once you have this covered its actually quite simple , you basically have to design it so that the gates fit in the normally cramped engine bay and so that your lines could be run properly and the exhaust from both gates can be collected and piped away. There isn't much more to it since the exhaust from your motor is under high pressure and will flow round almost any angle bend and through relatively long runs of pipe.
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Old 05-21-2004, 06:27 AM
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Originally Posted by roadkill669' date='May 19 2004, 05:38 PM
I have 2 38mm wastgates on my manifold and they are awesome. I have a turbonetics one and a tial. To sync them up, the tial had a 1 bar spring, and the turbonetics had a 5 psi, but I can adjust it. So I hooked it up to a known pressure source (hooked it up to the Tial since I cant boost lower than 14.7 on it and turned the pressure up until it barely started to open), then I hooked it up to the turbonetics and adjusted it. I have tested these things alot and they open at the same pressure, even on the car while its boosting.



It is a crazy setup to design, but its easier to do when you build the manifold and DP to accomidate these wastegates.
To sync them up, the tial had a 1 bar spring, and the turbonetics had a 5 psi, but I can adjust it. So I hooked it up to a known pressure source (hooked it up to the Tial since I cant boost lower than 14.7 on it and turned the pressure up until it barely started to open), then I hooked it up to the turbonetics and adjusted it.


This is of course the simple way (should work for most people just fine). I had tried this by T'ing the wastegates to a pressure regulator but but ran into some problems due to the effect of exhaust pressure being different on the two wastegates (at the time they were two quite different ones).
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Old 05-22-2004, 04:22 AM
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Wow thanks for all the info. I think i am just going to get one larger one. I was also told once i get my A/R upgraded to a proper size that will help as well. Currently it is only .70 and i want to go to a .84
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