Choosing Wastegate/s
02-24-16, 09:33 PM
#1
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Thread Starter
Choosing Wastegate/s
So I am going large single turbo on my FD. I bought a Borg Warner EFR EWG twinscroll 9180.
I'm trying to make sure I make the right decision on wastegate or wastegates for it as I've never had a twin scroll before.
I found a small tid-bit of info. on Turbosmarts website and I am just wondering if you more experienced, mechanical and tuning savvy folks would mind to lend some advice on this.
This is off TurboSmarts site
"Can you shed some light on wastegate sizing in relation to engine size and power output, i.e. does a high horsepower motor need a bigger wastegate compared to the same motor with low horsepower output? Also, on a twin scroll manifold/turbo setup running an external wastegate will a feed from each scroll into one wastegate be okay, or to do it properly should you run two wastegates, one for each scroll?
Turbosmart: This is a tricky question, and unfortunately there is no easy answer. To determine the correct size of a wastegate you must first look at engine size and target power. This will give you the mass airflow require to produce that power – from that a turbocharger is chosen. Once you know how much mass flow the engine puts out and how much mass flow the turbine requires, you’ll then be able to determine how much mass flow the wastegate needs to bypass to keep the turbine running in its optimum range. As you can see, this throws up an infinite number of variables related to wastegate sizing. All applications differ slightly, so it is best to speak with an experienced engine builder or tuner for advice on what’s been tried and tested. If you are tossing up between two wastegate sizes, it’s always better to go larger as this gives you more ability to control boost with future modifications and it will give the wastegate better heat handling capabilities.
In terms of twin scroll turbochargers, always run twin wastegates as the turbine housing is designed to have split exhaust pulses all the way to the turbine wheel. Using a single wastegate will bridge the exhaust pulse and have a negative effect on turbocharger performance to the point where it will have slower spool up even compared to a single scroll turbocharger."
Thank you in advance for any further light to be shead.
I'm trying to make sure I make the right decision on wastegate or wastegates for it as I've never had a twin scroll before.
I found a small tid-bit of info. on Turbosmarts website and I am just wondering if you more experienced, mechanical and tuning savvy folks would mind to lend some advice on this.
This is off TurboSmarts site
"Can you shed some light on wastegate sizing in relation to engine size and power output, i.e. does a high horsepower motor need a bigger wastegate compared to the same motor with low horsepower output? Also, on a twin scroll manifold/turbo setup running an external wastegate will a feed from each scroll into one wastegate be okay, or to do it properly should you run two wastegates, one for each scroll?
Turbosmart: This is a tricky question, and unfortunately there is no easy answer. To determine the correct size of a wastegate you must first look at engine size and target power. This will give you the mass airflow require to produce that power – from that a turbocharger is chosen. Once you know how much mass flow the engine puts out and how much mass flow the turbine requires, you’ll then be able to determine how much mass flow the wastegate needs to bypass to keep the turbine running in its optimum range. As you can see, this throws up an infinite number of variables related to wastegate sizing. All applications differ slightly, so it is best to speak with an experienced engine builder or tuner for advice on what’s been tried and tested. If you are tossing up between two wastegate sizes, it’s always better to go larger as this gives you more ability to control boost with future modifications and it will give the wastegate better heat handling capabilities.
In terms of twin scroll turbochargers, always run twin wastegates as the turbine housing is designed to have split exhaust pulses all the way to the turbine wheel. Using a single wastegate will bridge the exhaust pulse and have a negative effect on turbocharger performance to the point where it will have slower spool up even compared to a single scroll turbocharger."
Thank you in advance for any further light to be shead.
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959595rotor (05-05-23)
02-24-16, 09:55 PM
#2
Bigger boost application dont need as much wastegate as smaller boost applications. i'm running a pair of Turbosmart compgate 40mm with an efr8374 1.0 on an extend (street) port 13b. They work very well, can run a rock solid 7psi off 7psi springs, so can only assume could go even lower boost with softer springs if i wanted. BUT. I over heated one, the diaphragm failed and ended up replacing the whole wastegate. Its probably due to stagnant air, especially on the dyno. Need to get around to ducting some cold air on to it.
My 2c - they are a knock off of the tial MVS except without water cooling. If you use them keep an eye on the colour of the anodising. Its a good indicator of overheating. The one i replaced is already starting to go from the original black to brown again. OR use the raceport ones (longer, with cooling fins) or tial MVS-R, if you have room. Or if you can be arsed plumbing water lines use the tial MVS.
I dare say twin 40mm or single 60mm should do the trick for most applications. as TS has stated, check what others are doing on here. Hopefully someone with more experiance than myself will chime in on the topic.
My 2c - they are a knock off of the tial MVS except without water cooling. If you use them keep an eye on the colour of the anodising. Its a good indicator of overheating. The one i replaced is already starting to go from the original black to brown again. OR use the raceport ones (longer, with cooling fins) or tial MVS-R, if you have room. Or if you can be arsed plumbing water lines use the tial MVS.
I dare say twin 40mm or single 60mm should do the trick for most applications. as TS has stated, check what others are doing on here. Hopefully someone with more experiance than myself will chime in on the topic.
Last edited by WANKfactor; 02-24-16 at 09:58 PM.
02-25-16, 07:48 AM
#3
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Thread Starter
Thanks for the info. Yeah I've just got people and the internet telling me two different things lol. Some say with a twin scroll that dual wastegates is the correct and proper way and others saying a large single wastegate will do. I just want to ensure the longevity and proper efficiency of my turbo.
Our HP goals on the car at the moment are between 600-700 hp till I'm ready to make the leap to a 20b. I bought my turbo a bit on the larger size for a 600-700hp build, that way I wouldn't have to buy another in the future as it is rated for between 700-1000hp. At least that was the idea anyway. LOL We'll see. I'll keep digging around some. Thank you again!
Our HP goals on the car at the moment are between 600-700 hp till I'm ready to make the leap to a 20b. I bought my turbo a bit on the larger size for a 600-700hp build, that way I wouldn't have to buy another in the future as it is rated for between 700-1000hp. At least that was the idea anyway. LOL We'll see. I'll keep digging around some. Thank you again!
02-25-16, 09:55 AM
#5
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Thread Starter
Any thoughts on wastegate/s? Advantages and disadvantages of having one vs dual for a twin scroll? That's pretty much my hold up at the moment. Been digging around since last night and there is just so much conflicting info out there.
02-25-16, 02:11 PM
#6
Rotary Enthusiast
Dual gates are just better with a twin scroll turbo. The gains are small but real. And it does have all the theory & science on its side.
IMO the only downsides to twin gates/twin scroll is the extra cost of having to buy 2 gates, the extra space required, and the extra hose required. (not that that's a real issue, you just tee them together)
Also if your wanting to plumb the gates back into the downpipe (which I highly doubt your wanting to do with a 6-700hp car) it gets a bit trickier with twin gates
IMO the Pro's of a single gate setup is its cheaper and simpler.. thats about it.
IMO the only downsides to twin gates/twin scroll is the extra cost of having to buy 2 gates, the extra space required, and the extra hose required. (not that that's a real issue, you just tee them together)
Also if your wanting to plumb the gates back into the downpipe (which I highly doubt your wanting to do with a 6-700hp car) it gets a bit trickier with twin gates
IMO the Pro's of a single gate setup is its cheaper and simpler.. thats about it.
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02-25-16, 02:43 PM
#9
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Thread Starter
Would the TiaL 44mm MVR gates be in this "shorty" category?
02-25-16, 03:15 PM
#10
Rotary Enthusiast
that would be in the shorty category, however I think most manifolds come setup for MVS (38mm) wastegates. So depends what manifold you go with. If your going custom you can have whatever you want.
But yea the tial gate in the appropriate size for your manifold is the go.
Im running 2 x Tial MVS 38mm
But yea the tial gate in the appropriate size for your manifold is the go.
Im running 2 x Tial MVS 38mm
02-25-16, 03:22 PM
#11
Im not sure without looking it up. But in fairness, my set up is on a RHD and plumb-back so its very cluttered. Only one of my gates is overheating, ironically its the one that lookslike it should be less prone. Its not egt related either.
The Tial "shorty" gates have provision for water cooling and are described as for street use.
The racing ones have a longer body and no water cooling.
The Tial "shorty" gates have provision for water cooling and are described as for street use.
The racing ones have a longer body and no water cooling.
02-25-16, 03:39 PM
#12
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Thread Starter
Well so far I've found two manifolds, one being the turblown and the other the full race that are set up for EFR EWG twinscroll turbos. Both look lovely and I wouldn't really see a need for a custom one right at this moment. The only difference between the two of them from what I can visually see online is the placement of where the wastegates would go. I don't know enough about this to know if that makes a difference or not, so I'm still reading. Lol. Lot more to this stuff than I originally thought.
02-25-16, 04:04 PM
#14
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02-25-16, 05:48 PM
#16
Rx7ViXeN
Would the TiaL 44mm MVR gates be in this "shorty" category?
They are short, but they overcome the heat problem by offering the option of water cooling.
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The exhaust manifold design regarding the wategate runner merge from the main exhaust runners will have the biggest impact on wastegate application.
If you go with high priority (low merge angle) you get the best flow, but the most influence of Exhaust Manifold Pressure on boost control. You may have to set up your WG(s) in the dual port mode so the boost pressure above keeps the WG shut despite the EMP pushing it open.
If you go with low priority (high merge angle) you will get worse wastegate flow, but boost control will be easier on single port WG set up as EMP affect on WG is decreased.
The Full race manifold is very low WG priority manifold.
Full race will tell you their WG placement is correct and will not work with you on manifold design (I called).
The Turblown long runner dual WG manifolds are very high WG priority.
The old Turblown short runner dual WG manifolds are high WG priority.
The difference between Turblown long and short WG priority that I have seen is the long uses a bend off the runner and short uses a straight tube section off the runner. I am sure Turblown can build you a shorty with the bend section into the WG.
Turblown will work with you for whatever you want in a manifold.
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I have found divided exhaust pulses help spool very slightly in the very low RPMs on a turbo where I had it set up both ways with no other changes.
I went with Dual MVR in high WG priority position on my little EFR 7670 divided scroll turbo as I wanted the best response from keeping the exhaust pulses completely divided and a large WG area with good WG flow for decreased EMP.
I think a single 60mm WG would work fine with the EFR 9180, you just want to make sure your WG runners to it are even length and match the length to the turbo exhaust wheel for best pulse tuning.
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Sound- it matters to some.
In general, an exhaust manifold with low WG priority and an open dump will tend to have that more hollow sound when the external WG opens (Djuuuuuu).
In general, a manifold with high WG priority and open dump will tend to have that sharp NA rotary sound when it opens (Braaaaaaa).
In general, a manifold with dual WGs and an open dump will typically have a clearer, sharper rotary sound compared to a larger single WG (BRAAAAAA).
I say in general, because there are many other factors that will affect the open dump sound including power level (pressure of combustion event), boost levels (exhaust manifold pressure), ignition timing, AFRs, where the dump is pointed, and atmospheric conditions.
IDK if you can even tell the difference. I mean, to me a rotary just always sounds terrible. The worse it sounds the faster it seems to be.
Here is my TII on 60mm single wastegate-
And here on dual 44mm MVRs-
Would the TiaL 44mm MVR gates be in this "shorty" category?
They are short, but they overcome the heat problem by offering the option of water cooling.
---------
The exhaust manifold design regarding the wategate runner merge from the main exhaust runners will have the biggest impact on wastegate application.
If you go with high priority (low merge angle) you get the best flow, but the most influence of Exhaust Manifold Pressure on boost control. You may have to set up your WG(s) in the dual port mode so the boost pressure above keeps the WG shut despite the EMP pushing it open.
If you go with low priority (high merge angle) you will get worse wastegate flow, but boost control will be easier on single port WG set up as EMP affect on WG is decreased.
The Full race manifold is very low WG priority manifold.
Full race will tell you their WG placement is correct and will not work with you on manifold design (I called).
The Turblown long runner dual WG manifolds are very high WG priority.
The old Turblown short runner dual WG manifolds are high WG priority.
The difference between Turblown long and short WG priority that I have seen is the long uses a bend off the runner and short uses a straight tube section off the runner. I am sure Turblown can build you a shorty with the bend section into the WG.
Turblown will work with you for whatever you want in a manifold.
-----------
I have found divided exhaust pulses help spool very slightly in the very low RPMs on a turbo where I had it set up both ways with no other changes.
I went with Dual MVR in high WG priority position on my little EFR 7670 divided scroll turbo as I wanted the best response from keeping the exhaust pulses completely divided and a large WG area with good WG flow for decreased EMP.
I think a single 60mm WG would work fine with the EFR 9180, you just want to make sure your WG runners to it are even length and match the length to the turbo exhaust wheel for best pulse tuning.
------------
Sound- it matters to some.
In general, an exhaust manifold with low WG priority and an open dump will tend to have that more hollow sound when the external WG opens (Djuuuuuu).
In general, a manifold with high WG priority and open dump will tend to have that sharp NA rotary sound when it opens (Braaaaaaa).
In general, a manifold with dual WGs and an open dump will typically have a clearer, sharper rotary sound compared to a larger single WG (BRAAAAAA).
I say in general, because there are many other factors that will affect the open dump sound including power level (pressure of combustion event), boost levels (exhaust manifold pressure), ignition timing, AFRs, where the dump is pointed, and atmospheric conditions.
IDK if you can even tell the difference. I mean, to me a rotary just always sounds terrible. The worse it sounds the faster it seems to be.
Here is my TII on 60mm single wastegate-
And here on dual 44mm MVRs-
02-25-16, 06:15 PM
#17
Everyone above me is absolutely right, wastegate priority is what the manifold should be built around.
Feel free to shoot me an email with any questions! john@gleasemanufacturing.com
Feel free to shoot me an email with any questions! john@gleasemanufacturing.com
02-27-16, 08:23 AM
#18
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02-27-16, 10:24 AM
#19
Racing Rotary Since 1983
iTrader: (6)
EFR 9180 makes 94 pounds of air.
94 X 14.471 = 1360 CFM/ 1.92 = 708 SAE rotary rwhp
WG sizing depends on numerous factors. i have run my EFR9180 properly w a single 60 mm but it is quite dependent on manifold design.
WG piston area:
2 38 mm 3.51 sq inches
2 44 mm 4.71 sq inches
1 44 mm 2.35 sq inches
1 60 mm 4.38 sq inches
generally if you melt a WG diaphragm it is because the manifold design placed the WG in a hot area so the design is the problem not the WG.
HC
94 X 14.471 = 1360 CFM/ 1.92 = 708 SAE rotary rwhp
WG sizing depends on numerous factors. i have run my EFR9180 properly w a single 60 mm but it is quite dependent on manifold design.
WG piston area:
2 38 mm 3.51 sq inches
2 44 mm 4.71 sq inches
1 44 mm 2.35 sq inches
1 60 mm 4.38 sq inches
generally if you melt a WG diaphragm it is because the manifold design placed the WG in a hot area so the design is the problem not the WG.
HC
02-27-16, 04:41 PM
#20
^ yes, mine is a RHD steering box FB, so very tight, even though i put a lot of effort and thought into placement, its obviously not good enough, and under-bonnet aerodynamics I guess are weird as the WG that looks more open is the one with the issues.
I am sure it's not even an issue with the beautifully well designed manifolds offered by Gleaseman, IRP, Turblown, ect.
Just putting it out there that it should be a consideration, especially on a custom set up that you are planning to give a hard time.
I am sure it's not even an issue with the beautifully well designed manifolds offered by Gleaseman, IRP, Turblown, ect.
Just putting it out there that it should be a consideration, especially on a custom set up that you are planning to give a hard time.
Last edited by WANKfactor; 02-27-16 at 04:43 PM.
02-28-16, 07:53 AM
#21
^ yes, mine is a RHD steering box FB, so very tight, even though i put a lot of effort and thought into placement, its obviously not good enough, and under-bonnet aerodynamics I guess are weird as the WG that looks more open is the one with the issues.
I am sure it's not even an issue with the beautifully well designed manifolds offered by Gleaseman, IRP, Turblown, ect.
Just putting it out there that it should be a consideration, especially on a custom set up that you are planning to give a hard time.
I am sure it's not even an issue with the beautifully well designed manifolds offered by Gleaseman, IRP, Turblown, ect.
Just putting it out there that it should be a consideration, especially on a custom set up that you are planning to give a hard time.
Tial mvr44s will not fit our ewg fd manifold. Tial mvs or turbosmart comp40 only. We have a lot of customers running both without issue. Iwg is by far best for wastegate reliability( even Borgwarner states this). Less than 2 percent of iwg owners cannot run less than 17 psi on 8374 models however. I was able to hold 8 psi on my 9180 iwg, but as soon as I went 4 inch it would creep to 18 psi. If you are looking to run a 9180 you should not be running less than 20 psi anyhow...
Last edited by Turblown; 02-28-16 at 07:55 AM.
02-28-16, 08:15 PM
#22
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Thread Starter
Okay so my next question for EWGs is, What are the advantages or disadvantages of open dump tubes rather than routing it back into the exhaust?
I really appreciate everyones knowledge and time by the way on schooling me some! You guys have been great!!! Thank you all!
I really appreciate everyones knowledge and time by the way on schooling me some! You guys have been great!!!
Thank you all!
02-28-16, 09:21 PM
#23
Rotary Enthusiast
Basically, Routed back = much quieter. Slightly more back pressure. Minimal difference in power in the real world, maximum difference in noise.
Open Dumps = lnsane loud. Like running no exhaust when gates are open. Potentially slightly more power due to less back pressure.
IMO the power part of it dosent matter unless your going for the extreme. The difference is small and not worth bothering about, there are other factors to consider.
e.g rough example of trade-off might be open dump car makes 400hp, vs plumbed back car making 390hp with an otherwise same setup. Open dump car may make 120db noise, vs plumbed back car making 95db noise.
Whats important is how much noise can you handle, and do you need to meet any noise or exhaust requirements in order for you car to be street legal? (if your wanting it to be street legal)
e.g. down here in NZ, the gates need to be plumbed back into the exhaust for it to be road legal. That may or may not be a factor for you.
Personally, if given the choice. On anything but a track machine I would have the gates plumbed back.
EDIT; plumbing the gates back also takes a bit of extra fab work. I dont think many places sell the downpipe/manifold/turbo setup all setup to be plumbed back. (maybe you can request it though) Most just sell the manifold, a downpipe and open dump tubes. You may need to just get the manifold & have a plumb back down pipe made up if you want to go that route.
Open Dumps = lnsane loud. Like running no exhaust when gates are open. Potentially slightly more power due to less back pressure.
IMO the power part of it dosent matter unless your going for the extreme. The difference is small and not worth bothering about, there are other factors to consider.
e.g rough example of trade-off might be open dump car makes 400hp, vs plumbed back car making 390hp with an otherwise same setup. Open dump car may make 120db noise, vs plumbed back car making 95db noise.
Whats important is how much noise can you handle, and do you need to meet any noise or exhaust requirements in order for you car to be street legal? (if your wanting it to be street legal)
e.g. down here in NZ, the gates need to be plumbed back into the exhaust for it to be road legal. That may or may not be a factor for you.
Personally, if given the choice. On anything but a track machine I would have the gates plumbed back.
EDIT; plumbing the gates back also takes a bit of extra fab work. I dont think many places sell the downpipe/manifold/turbo setup all setup to be plumbed back. (maybe you can request it though) Most just sell the manifold, a downpipe and open dump tubes. You may need to just get the manifold & have a plumb back down pipe made up if you want to go that route.
Last edited by 96fd3s; 02-28-16 at 10:41 PM.
02-29-16, 03:38 AM
#24
Full Member
Indeed agree with the above.. I'm building my engine with similar spec as you
- twin scroll turbo EFR 9174
- twin scroll manifold with dual gates progate 40's, gates vent to atmosphere(!)
All this on a large streetported engine and ported Intake from TB to LIM shooting for 600+ Whp. I'm going to make some ducting for my gates to aid cooling doesn't have to be much, just run 2 air tunnels or 1 bigger one and place it strategically in your bay pointing towards the gates and you should be fine!
pic of my custom made mani:
If you're interested in one shoot me a PM and i can get you one for an unbeatable price!
Best of luck!
- Eplusz
- twin scroll turbo EFR 9174
- twin scroll manifold with dual gates progate 40's, gates vent to atmosphere(!)
All this on a large streetported engine and ported Intake from TB to LIM shooting for 600+ Whp. I'm going to make some ducting for my gates to aid cooling doesn't have to be much, just run 2 air tunnels or 1 bigger one and place it strategically in your bay pointing towards the gates and you should be fine!
pic of my custom made mani:
If you're interested in one shoot me a PM and i can get you one for an unbeatable price!
Best of luck!
- Eplusz
02-29-16, 09:37 AM
#25
Basically, Routed back = much quieter. Slightly more back pressure. Minimal difference in power in the real world, maximum difference in noise.
Open Dumps = lnsane loud. Like running no exhaust when gates are open. Potentially slightly more power due to less back pressure.
IMO the power part of it dosent matter unless your going for the extreme. The difference is small and not worth bothering about, there are other factors to consider.
e.g rough example of trade-off might be open dump car makes 400hp, vs plumbed back car making 390hp with an otherwise same setup. Open dump car may make 120db noise, vs plumbed back car making 95db noise.
Whats important is how much noise can you handle, and do you need to meet any noise or exhaust requirements in order for you car to be street legal? (if your wanting it to be street legal)
e.g. down here in NZ, the gates need to be plumbed back into the exhaust for it to be road legal. That may or may not be a factor for you.
Personally, if given the choice. On anything but a track machine I would have the gates plumbed back.
EDIT; plumbing the gates back also takes a bit of extra fab work. I dont think many places sell the downpipe/manifold/turbo setup all setup to be plumbed back. (maybe you can request it though) Most just sell the manifold, a downpipe and open dump tubes. You may need to just get the manifold & have a plumb back down pipe made up if you want to go that route.
Open Dumps = lnsane loud. Like running no exhaust when gates are open. Potentially slightly more power due to less back pressure.
IMO the power part of it dosent matter unless your going for the extreme. The difference is small and not worth bothering about, there are other factors to consider.
e.g rough example of trade-off might be open dump car makes 400hp, vs plumbed back car making 390hp with an otherwise same setup. Open dump car may make 120db noise, vs plumbed back car making 95db noise.
Whats important is how much noise can you handle, and do you need to meet any noise or exhaust requirements in order for you car to be street legal? (if your wanting it to be street legal)
e.g. down here in NZ, the gates need to be plumbed back into the exhaust for it to be road legal. That may or may not be a factor for you.
Personally, if given the choice. On anything but a track machine I would have the gates plumbed back.
EDIT; plumbing the gates back also takes a bit of extra fab work. I dont think many places sell the downpipe/manifold/turbo setup all setup to be plumbed back. (maybe you can request it though) Most just sell the manifold, a downpipe and open dump tubes. You may need to just get the manifold & have a plumb back down pipe made up if you want to go that route.
However if you are looking to reroute your wastegates, without a DOUBT choose an IWG EFR, Especially on a dual wastegate setup.