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Old 06-12-2013, 01:27 AM   #1
elblanco1987
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Default 44mm ewg too big?

I'm thinking of getting a used 44mm ewg and up pipe from someone on the site. But my buddie said that 44mm is too big for my setup. Cobb sf, invidia Catted turbo back, and Perrin bpv, Somebody give me a little info?
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Old 06-12-2013, 02:33 AM   #2
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Originally Posted by elblanco1987 View Post
I'm thinking of getting a used 44mm ewg and up pipe from someone on the site. But my buddie said that 44mm is too big for my setup. Cobb sf, invidia Catted turbo back, and Perrin bpv, Somebody give me a little info?
Your buddy is wrong on this one.

38mm=High boost applications
44mm=low boost applications

Lastly, when it all comes down to it just get a competent tuner, the right wastegate spring, a tune and you'll be all set with either sizes.
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Old 06-12-2013, 05:24 AM   #3
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Vince, can you expand upon that? Seems backwards to me that a larger WG would be better suited to lower boost levels. I'm a boost noob so just asking for some insight
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Old 06-12-2013, 05:43 AM   #4
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If you're trying to keep your boost low, you're going to have to bypass a lot of the exhaust gases past the turbine through the wastegate.

More gases will flow better through a larger wastegate.
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Old 06-12-2013, 06:53 AM   #5
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38mm=low boost applications
44mm=High boost applications
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Old 06-12-2013, 07:16 AM   #6
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Quote:
Originally Posted by scott06sti View Post
38mm=low boost applications
44mm=High boost applications
This is the correct one.....

And yes, it's too big for you. You would require the 38mm.
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Old 06-12-2013, 07:39 AM   #7
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it has NOTHING to do with boost pressure, and everything to do with mass air flow through the wastegate.
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Old 06-12-2013, 09:42 AM   #8
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Quote:
Originally Posted by scott06sti View Post
38mm=low boost applications
44mm=High boost applications
Quote:
Originally Posted by Cathexis View Post
This is the correct one.....

And yes, it's too big for you. You would require the 38mm.
WTF? Please tell me sarcasm is running rampant through this thread...

44mm is for any application
38mm is ONLY for applications where you don't need to flow a low of air through the wastegate

Read that again...

44mm is for any application
38mm is ONLY for limited applications

If you're not sure, go 44mm. If you're running a big turbo, go 44mm. If you're running low boost, go 44mm. ONLY if you're running a smallish turbo with high boost should you go 38mm. The 38mm does not have any advantages over the 44mm, and there are NO situations in which a 44mm will not work but a 38mm will (there are plenty of situations in which a 38mm will not work and a 44mm will, though).


The question itself is misleading..."44mm ewg too big?" There's no such thing as "too big" when you're talking about wastegates. There's "bigger than necessary", but that's significantly different. It can certainly be "too small" though.

Last edited by the suicidal eggroll; 06-12-2013 at 09:50 AM.
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Old 06-12-2013, 11:33 AM   #9
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^ this is the only true answer. nicely summed up eggroll.

FWIW, I am using a 38mm EWG on my vf52 and I will consider to do so when I switch to a 20g turbo. The only reason I am using the smaller EWG is because I'll be running high boost.

Last edited by Mr Wrex; 06-13-2013 at 11:26 AM. Reason: fixed for clarity
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Old 06-12-2013, 11:38 AM   #10
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blow air through it with your mouth or even scream
only way to find out if its enough

Last edited by coalslaw; 06-13-2013 at 12:31 AM.
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Old 06-12-2013, 02:56 PM   #11
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Quote:
Originally Posted by scott06sti View Post
38mm=low boost applications
44mm=High boost applications
Quote:
Originally Posted by Cathexis View Post
This is the correct one.....

And yes, it's too big for you. You would require the 38mm.
Please do not post "facts" on subjects you have not researched...
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Old 06-12-2013, 03:03 PM   #12
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Originally Posted by the suicidal eggroll View Post
WTF? Please tell me sarcasm is running rampant through this thread...
no, just noobs.
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Old 06-12-2013, 09:04 PM   #13
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Welp. Looks like ill be getting the 44mm since it seems it'll work with my current setup and once I get a bigger turbo
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Old 06-12-2013, 09:33 PM   #14
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FWIW, I will be using a 38mm EWG even when I switch to a 20g turbo, but that's only because I'll be running high boost.
Nothing wrong with the 38mm gate, I hope I didn't imply that in my post.

The 38mm gate is perfectly acceptable and will work for most setups, one just needs to be aware of the limitations and make sure that it won't create a bottleneck in their application.

There are two types of people who run a 38mm gate:

1) Those who know what the difference is, and know that a 38mm gate will work correctly for their application. Whether it's through experience, research, following a similar build, or whatever else may be the case.

2) Those who don't know what's going on and simply pick the cheaper option.


People in camp #2 would be better off picking the 44mm just in case they need it and don't realize.

When it comes to wastegates, if you're unsure then go big. It's not like turbos where going too big will have a downside that needs to be weighed against the benefits. There really is no downside to going bigger than necessary on the wastegate, other than cost.
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Old 06-13-2013, 12:01 AM   #15
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What are we considering high boost?
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Old 06-13-2013, 07:58 AM   #16
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I know my 44mm has held 30 psi and my car is still running good, so from my point of veiw it is all up to the person if you want 38mm or 44mm with the springs that come with them ethier one will do almost what the other will. The 44mm will let air flow faster being a little bigger, with the 38mm it will build pressure a little faster being smaller, but that is way so many people blow one of these engines to think the 38mm is better. Mine is still running high boost since 06 how many people can say that their car is still running.
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Old 06-13-2013, 10:38 AM   #17
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with the 38mm it will build pressure a little faster being smaller

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Old 06-13-2013, 11:17 AM   #18
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Originally Posted by the suicidal eggroll View Post
Nothing wrong with the 38mm gate, I hope I didn't imply that in my post.
You didn't imply that whatsoever, don't sweat it!

Quote:
Originally Posted by the suicidal eggroll View Post
The 38mm gate is perfectly acceptable and will work for most setups, one just needs to be aware of the limitations and make sure that it won't create a bottleneck in their application.

There are two types of people who run a 38mm gate:

1) Those who know what the difference is, and know that a 38mm gate will work correctly for their application. Whether it's through experience, research, following a similar build, or whatever else may be the case.

2) Those who don't know what's going on and simply pick the cheaper option.


People in camp #2 would be better off picking the 44mm just in case they need it and don't realize.

When it comes to wastegates, if you're unsure then go big. It's not like turbos where going too big will have a downside that needs to be weighed against the benefits. There really is no downside to going bigger than necessary on the wastegate, other than cost.
OP, this should be the only thing you take as fact on this thread. As I stated earlier, a smaller EWG allows you to control higher levels of boost more effectively. You can run high boost on a 44mm EWG, but I've noticed firsthand that they're harder to tune with due to the larger diaphragm size.

Quote:
Originally Posted by Bru1212 View Post
What are we considering high boost?
As for the question about what constitutes a "low boost" application... it depends on capability of the turbo you are using. If you get a turbo that can run up to 30psi but you only want to run 17psi, that would be considered "low boost". I am running 22psi on my vf52 (24psi on e85), which is pretty much the highest you can run it in its efficiency range. That is an example of a "high boost" application. The larger the EWG diaphragm, the easier it is to bypass exhaust gasses and keep the psi down lower. I'm sure eggroll will have another way to describe it in case my basic explanation may not fully make sense.

In the end, I would highly recommend talking to your tuner about what size he/she thinks is best for your setup. You will also want to ask about what size spring to use and research the different boost control setups you can use. I made a thread awhile back to compare the different kinds (MBC vs EBCS vs Hybrid) so check it out and let me know if you have any furthur questions!

Last edited by Mr Wrex; 06-13-2013 at 11:28 AM.
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Old 06-13-2013, 11:29 AM   #19
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I don't even know where to start here

The ONLY time we've ever seen the 38mm perform poorly is when the design (angle to flow, pipe size, length, etc...) was done poorly. The 38mm will work for 99.98% of Subaru applications IMO. The smaller gate will also gives added resolution or modulation of boost, however your tuner prefers to word it, over the larger 44mm.

We've done the 38mm on a 35R at 17psi and 26psi and both had duty cycle headroom.

Will the 44mm do the job too. Sure. The larger the gate the bigger the oscillations in feedback boost will be seen with but enough ECU resolution it's compensated for anyway and it's not enough to 'feel'. So they both will work.

A WG is just a simple pressure regulation valve. It open when there is too much boost pressure and closes when it needs to build more. The size of the gate is the size of the hole you are opening to regulate the pressure. The smaller valve will give more precise control and the bigger valve can flow more, if needed. If the Suby setup wasn't so inefficient from the get-go I'm sure the 44mm would make more sense in more applications.

Just my 2 cents
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Old 06-13-2013, 11:50 AM   #20
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OP, this should be the only thing you take as fact on this thread.
how paradoxical.
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Old 06-13-2013, 11:12 PM   #21
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I don't even know where to start here

The ONLY time we've ever seen the 38mm perform poorly is when the design (angle to flow, pipe size, length, etc...) was done poorly. The 38mm will work for 99.98% of Subaru applications IMO. The smaller gate will also gives added resolution or modulation of boost, however your tuner prefers to word it, over the larger 44mm.

We've done the 38mm on a 35R at 17psi and 26psi and both had duty cycle headroom.

Will the 44mm do the job too. Sure. The larger the gate the bigger the oscillations in feedback boost will be seen with but enough ECU resolution it's compensated for anyway and it's not enough to 'feel'. So they both will work.

A WG is just a simple pressure regulation valve. It open when there is too much boost pressure and closes when it needs to build more. The size of the gate is the size of the hole you are opening to regulate the pressure. The smaller valve will give more precise control and the bigger valve can flow more, if needed. If the Suby setup wasn't so inefficient from the get-go I'm sure the 44mm would make more sense in more applications.

Just my 2 cents
This is the most complete answer. Bigger is better, until is starts to be hard to control. I also bet the 38mm would be insufficient if you were trying to run that 35R at 12psi.
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Old 06-14-2013, 05:56 AM   #22
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think about what you're claiming: that a 1.5" round hole in your exhaust wouldn't pass enough gas to prevent a 35r from hitting 12psi.
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Old 06-14-2013, 06:20 AM   #23
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think about what you're claiming: that a 1.5" round hole in your exhaust wouldn't pass enough gas to prevent a 35r from hitting 12psi.
^ and an even simpler way to put it

Considering a 35R's turbine inlet is ~47mm, the 38mm WG has plenty of flow to modulate boost.
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Old 06-14-2013, 08:24 AM   #24
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My buddy has a 67mm turbo on his 2JZ, with a tial 38. At 18psi, it's just fine.

I have a tial 38 on my vf39, at 18psi, it's just fine.
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Old 06-15-2013, 06:04 PM   #25
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38mm sound ricey so you should get a 44mm

Your buddy is an idiot. Either will work and either will do the same thing for your setup.
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