Wastegate on Mid turbo housing
#23
8 Second Club
iTrader: (4)
You want the WG to have a wide range of motion to control your boost to keep control the most accurate possible. It’s similar to running a 4 bar map sensor to run 1 bar of boost. You lose resolution.
With a 60mm+ valve you’ll have a large fluctuation in boost pressure with VERY little valve movement, that’s not ideal. A WG that is too small is no better.
Also have to take into consideration valve face area VS dome diaphragm area. You want the dome/diaphragm area to be larger than the valve area.
Look at a 38mm WG compared to your 60mm WG. You’ll notice your gate doesn’t have a proportionally large “dome” when compared to a 38mm gate. This means you’ll need more pressure in the top port to hold the valve closed than you would with a smaller control valve. That's why on board air/co2 is usually used to control the large WG's.
Obviously companies want you to spend money. By the time you buy your huge gate, onboard air, and aftermarket boost controller... You can easily have $1500-2000+ into boost management. For most non-competition guys... boost management can be handled with a 38-44mm $60 WG and $3 boost valve.
With a 60mm+ valve you’ll have a large fluctuation in boost pressure with VERY little valve movement, that’s not ideal. A WG that is too small is no better.
Also have to take into consideration valve face area VS dome diaphragm area. You want the dome/diaphragm area to be larger than the valve area.
Look at a 38mm WG compared to your 60mm WG. You’ll notice your gate doesn’t have a proportionally large “dome” when compared to a 38mm gate. This means you’ll need more pressure in the top port to hold the valve closed than you would with a smaller control valve. That's why on board air/co2 is usually used to control the large WG's.
Obviously companies want you to spend money. By the time you buy your huge gate, onboard air, and aftermarket boost controller... You can easily have $1500-2000+ into boost management. For most non-competition guys... boost management can be handled with a 38-44mm $60 WG and $3 boost valve.
#24
I don't want to loose to much money and i paid a lot for this wastegate .. so what I'm going to do is this .. I had the 50mm wastegate next to the 60mm gate it's actually the same size the only difference is the intake side .. the JGS 50mm uses a 2 inch opening and the 60 mm uses a 2.5 opening .. instead of using a 2.5 tubing, I might use a 1 1/2 pipe or 2 inch to decrease the volume of air going in .. hopefully this works but it kinda makes sense to me.
#25
TECH Enthusiast
I think the key is when you come off the housing to keep the pipe off the housing tangential to the snail. You do not want it coming off the housing as a radius, like you were holding the gate in the first pic. The first picture it is perpendicular to the flow of gasses in the housing. In the second picture, I think the way you are holding the device with all the rods, (cool tool by the way) will give you the correct angle so the gasses will rush towards the gate. My thoughts are putting it there should work just fine as long as you don't cut too big of a hole.
I agree with you, you may want to put a smaller pipe on it, like a 1 1/2" then transition to a larger pipe to match your wastegate. I think that makes good sense. That way if you realize you need a smaller gate, and just can't get the big one to work the way you want it to, you won't have too big of a hole in your housing.
I agree with you, you may want to put a smaller pipe on it, like a 1 1/2" then transition to a larger pipe to match your wastegate. I think that makes good sense. That way if you realize you need a smaller gate, and just can't get the big one to work the way you want it to, you won't have too big of a hole in your housing.
#27
TECH Resident
iTrader: (13)
What ForceFed said about the dome size with respect to the valve size is spot on. Remember that a force caused by pressure is simply: Pressure X Surface Area. With the larger 60mm valve, it will take less exhaust pressure to crack the valve. On the other end (the side keeping it closed) is the dome that sees pressure. If this surface area is smaller than the valve, then you need more pressure to provide the equivalent force to keep the valve closed. By making the pipe smaller feeding the inlet of the valve, your doing nothing because the valve surface area is still the valve surface area. What you are trying to accomplish there is decreasing flow which would only MAYBE (if you sized the feed pipe correctly and would likely need to be quite a bit smaller) is you might get slightly better resolution by restricting how easily exhaust flows across the valve as it is moved, as forcefed said early, but I highly doubt it.
You should either sell it and get a smaller gate (44mm should be a nice size) or run with it and just know that you may have some boost control issues. I would weld the gate inlet 90 degrees off the turbine so the valve doesn't see exhaust flow causing additional driving force to open it as well as aiding in flow going past the valve. This will end up requiring more pressure on the dome and will have less resolution in the control as a result, respectively.
You should either sell it and get a smaller gate (44mm should be a nice size) or run with it and just know that you may have some boost control issues. I would weld the gate inlet 90 degrees off the turbine so the valve doesn't see exhaust flow causing additional driving force to open it as well as aiding in flow going past the valve. This will end up requiring more pressure on the dome and will have less resolution in the control as a result, respectively.
#30
TECH Enthusiast
I would still keep the pipe going tangential, putting the pipe on the housing, at 90 degrees and using too large of a waste gate is doing 2 wrongs trying to make a right. The instructions I've got with the wastegates I've owned have always shown to install them with the gas glow towards them to have them work best. If you put the pipe on the housing correctly with the flow at the gate, then if, and probably when, you realize the waste gate really is too big and have to change to something like a 44-46 mm gate, you will only have to change the gate, and your plumbing will be correct. I've never used a wastegate that big, so I can't tell you from personal experience that it is too big, but that seems to be a common theme here amongst many replies. I think the odds are against you, but I understand wanting to try what you have first. You will only have 1 thing to fix(getting a smaller wastegate), your plumbing will be oriented correctly to the exhaust gas flow. Other wise you may need to get a new gate, and get a new turbine housing and start over to do it right. Just my opinion, something to think about.
Ultimately what keeps the wastegate closed is the spring and the pressure the boost controller is putting on the top side of the wastegate piston. I think the gate is mainly opened by the pressure applied to the underside of the piston, that comes from the boost line off the compressor housing. I think very little of the opening force comes from exhaust against the valve. Here is my logic for this. I have tested my wastegate using my air compressor. It opens at about 17 psi pressure from my air compressor applied to the underside of the piston in the waste gate. This is off the car with no exhaust pressure against the seat. On the car, in normal operation, it opens at about 16.5 psi, with exhaust pushing against the valve of the waste gate. Therefore I determine the majority of the function of the wastegate is from the line coming from the compressor housing to the piston in the gate vs. exhaust gas pressure against the valve. This is because the gate opens at almost the same pressure under the piston, regardless of the exhaust gas pressure against the valve or not. I would say that the exhaust is contributing a little, but not much. I think the reason that the exhaust doesn't contribute much to the opening of the gate, is that once the valve gets off the seat just a little, the pressure leaks past the valve, and doesn't push against it. In the case of the compressor housing pressure pushing against the underside of the piston, there is a seal there so there is no where for the air to escape to, and it just puts all its force against the piston. This is based upon real world testing, not something I read somewhere on the internet, so I'm quite confident these statements are correct.
Ultimately what keeps the wastegate closed is the spring and the pressure the boost controller is putting on the top side of the wastegate piston. I think the gate is mainly opened by the pressure applied to the underside of the piston, that comes from the boost line off the compressor housing. I think very little of the opening force comes from exhaust against the valve. Here is my logic for this. I have tested my wastegate using my air compressor. It opens at about 17 psi pressure from my air compressor applied to the underside of the piston in the waste gate. This is off the car with no exhaust pressure against the seat. On the car, in normal operation, it opens at about 16.5 psi, with exhaust pushing against the valve of the waste gate. Therefore I determine the majority of the function of the wastegate is from the line coming from the compressor housing to the piston in the gate vs. exhaust gas pressure against the valve. This is because the gate opens at almost the same pressure under the piston, regardless of the exhaust gas pressure against the valve or not. I would say that the exhaust is contributing a little, but not much. I think the reason that the exhaust doesn't contribute much to the opening of the gate, is that once the valve gets off the seat just a little, the pressure leaks past the valve, and doesn't push against it. In the case of the compressor housing pressure pushing against the underside of the piston, there is a seal there so there is no where for the air to escape to, and it just puts all its force against the piston. This is based upon real world testing, not something I read somewhere on the internet, so I'm quite confident these statements are correct.
#31
I'm going to be honest , I bought the 60mm gate after actually reading quite a few guys having issue with boost creap , especially when you don't have the space to position the wastegate at the right angle and position.. rather they used dual wastegates or they used a 60. I told my self let me do it right from the beginning.. I'm going to buy the 60 , spend the money ($500) and get it over with ... now reading this post I'm not so confident. But if you search for guys using 60mm you really don't hear anything negative , I hear more negative from having to small of a gate .... actually coming to think about it I haven't come across any post that someone has had a negative effect on a large gate. So confusing lol
#32
I just called JGS and they said that I'm going to be messing trying to adjust the wastegate to much for such a little turbo .. they recommended their 50mm gauge that they will exchange it to.. so what did I learn .. bigger is not always better lol
#35
TECH Apprentice
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Join Date: Mar 2004
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Hey guys, I'm having difficulty locating a spot for my 60mm wastegate. I've read that is ok to place the wastegate in the turbo housing. Most of the pictures I've seen, the waste gate is located near the flange. My question is can I move the wategate towards the rear, away from the flange? Would it still work?
Here are some pictures so you guys get an idea.
Here are some pictures so you guys get an idea.
What's that tool called?
#38
Man I'm so mad , had my o2 bungs welded and now the bung caps are stuck ... I've tried using a torch and they only move about 1/8 of inch ... one cap is rounded and the other one is a no go! I guess I have to seal them and pick another spot .
#40
What did you learn from not using the 60m to using a 50mm?