2plus4plus0eq6

Hi,

Like the title says.. whats really the difference. I understand that an internal wastegate cannot be removed because the actuator opens the dump plate, but with external one, is it optional?

Correct me if I am wrong, but I think an external wastegate opens and closes the plate by utilizing a low port and a high port on the turbo and by changing the pressure it can position the dump plate?

Isn't it really just a pressure valve just like a manual boost controller?

Sorry for the dumb question. I tried googling, but I must not have typed in the correct phrase or something. I think I'm slowly getting it..

Thanks

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Dboyizmlg

You CAN remove the internal WG actuator. Just need to weld the flapper door closed shut, and run an external WG.

Codyace has done this to his bottom mount set up, so have many others.

You will get much better accurate boost control with external WG.
No boost creep issues like the internal.

wurley

1. - what do you mean an internal cannot be removed? They cant be "taken out", but welded shut or a different exhaust housing w/o a w/g can be installed on the turbo

- what is optional?

2. - idk what you mean by low port and high port. The w/g opens when the pressure (from a vacuum line) exceeds the spring valve.

3. - No. A boost control doesn't vent any exhaust gasses. Boost controls limit the pressure going to the wastegate, making it stay closed longer.

2plus4plus0eq6

Interesting.. didn't think about welding the flapper. Shouldn't have any boost creep if the internal wastegate was left on and a boost controller was added.

If there is no actuator with an external wastegate, then does a flapper still exist? If not, then whats the difference of a manual boost controller and an external wastegate??

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2plus4plus0eq6

Interesting.. didn't think about welding the flapper. Shouldn't have any boost creep if the internal wastegate was left on and a boost controller was added.

If there is no actuator with an external wastegate, then does a flapper still exist? If not, then whats the difference of a manual boost controller and an external wastegate??

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Dboyizmlg

Lol my friend looks like you have a lot of reading ahead of you.
Manual boost controllers are JUNK period!!!!

Invest in a electronic boost controller .

By the way, I have one for sale it's a mint condition low mileage EBC.
HKS evc -s asking price is $300.00 shipped.

LMK man

2plus4plus0eq6

haha I know. Ive been reading lots. My head hurts. This concept should seem simple. Im tired of people saying different things.. I know the advantages of an EBC, but I heard some magazine tested lot of high quality MBCs vs most EBCs. Apparently the MBCs outperformed most of the EBCs

I don't know what to think anymore.

Besides that, can you answer any of my questions from the previous post?

EDIT: What I meant to say was that... by welding the flapper closed which allows boost to build, a path still needs to exist for the boost to exit after letting off the throttle right? Now whats the difference between adding in an external wastegate and adding in a manual boost controller?

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joe3180

what do you think the boost controller would do without a wastegate whether internal or external to control? check out a diagram of how to install the boost controller and I think you will understand.

cotbu

Here it seems you confuse waste gates with blow off valve or bypass valves. You are just cufused. Search each item you have a question about on how stuff works.com and try to get a better idea off what each thing does. Boost is not exhaust although in a turbocharged application they seem synonymous!


From a Highly Tuned Note 4.5!!!

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LoverTechnologies "Half Broken Things!"

Croustibat

I second that.

Plus a "manual boost controler" is a pile of crap and by its design cannot be better than an electronic boost controler. I suggest you reread your magazines and stop trusting them if manual > electronic BC is written.

Just look at how they work. You don't need a magazine to tell you which system is better...

Def

The EWG top part with the ports *IS* the actuator assembly (same as the canister/actuator on an IWG). It has a diaphram connected to the wastegate valve (same function as the wastegate flapper on an IWG).

Same components between them, the only different is where they are, and that an IWG has a rod connecting the actuator to the flapper valve swing arm.

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S13 Hatch - Goes around tracks quickly
DEFSPORT

bmaddock

This thread was funny. I've been there too man, you'll figure it out.

Wastegate (internal or external) regulates how much boost is built.

Blow-off (bypass) valve relieves boost in the charge pipes to prevent compressor surge and reduce bearing wear and tear.

Boost controller (manual or electronic) is an additional piece that alters the amount of boost your wastegate spring sees. In other words it's sort of like pinching a garden hose... but where the water pressure just keeps increasing.. Basically it allows you to run the amount of boost your wastegate spring will allow or higher.

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Dboyizmlg

^^^ couldn't of said it any better.

S14DB

To complicate it more the Wastegate controls the flow of exhaust gasses to the turbine. When it is open it allows exhaust gas to bypass the turbine, regulating it's speed. Compressor speed determines flow and therefor boost.

People start over boosting because the diameter of the wastegate flapper is too small. Even with the flapper fully open the internal hole does not bypass enough to regulate the turbine. There is only so much room in a turbine housing for an internal gate. External gate allows you to run a much larger hole to regulate the flow better. Stock turbos usually do not experience exhaust flow higher than the stock gate can handle. Some T2 based upgrades can.

The actuator is a spring loaded diaphragm that starts to move the gate open as pressure(boost) is applied. It is mostly linear to open slowly as the boost increases to keep the boost pressure at a determined level. It takes time for the turbine to speed up and slow down.

Stock wategates can be replaced or upgraded with higher spring rates to increase the boost pressure. This is the preferred method to keep the boost regulation smooth and linear(in a properly designed system).

Like said above, MBCs are just a bandaid to make the actuator see less pressure than actual. Usually is done with a spring and ball bearing. When the pressure gets high enough it pushes the BB back and allows pressure to the actuator. Quality can vary and the risk of over boosting increases. The greater the differential between the MBC rate and the actuators rate the less linear the regulation gets. A 7psi actuator suddenly getting 14psi of pressure will open up rapidly. A higher rate actuator is always a better solution. Garrett makes 12~14 and 16~18psi actuators that fit on stock turbos.

EBCs give the most adjustment of pressure. But, they can also be the most difficult to tune. You have to set the target boost pressure and also the rate(gain) of the actuation(flow). It works similarly to the MBC regulating the boost pressure the actuator sees with a solenoid valve.
If done correctly the boost level will remain flat when the desired pressure is reached. Many modern turbo cars have a valve controlled by the ecu to control boost levels. Most ECU tunes raise the boost pressure using the factory boost control.
Done wrong it can behave like a MBC or worse. Opening to rapidly losing turbine velocity and having dropoff in pressure. Opening to late and having over boosting. Then the EBC tries to correct and you get a pogo effect of the boost rising and falling.
It is important to understand how the gain and target pressure are related and how they work in the EBC you choose. This is also why you will see varying reviews on EBCs because of how the software works and is presented. Some can be basic in their adjustment but hard to fine tune. Others have some learning features to self tune or help you dial it in. Your mileage may vary depending on your abilities and setup.


Basically, if you want to run one pressure all the time and want the simplest solution. Get an actuator set to the pressure you want. Garrett actuators are usually cheaper than a quality MBC.
If you want multiple pressures(street/race) and adjustable(gear dependent, ect) get an EBC. But, research before making a purchase.

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Comments should be taken as Opinions not as Statements of Fact

2plus4plus0eq6

I know how a boost controller works and I know how an internal wastegate works. Its really an external wastegate that throws me off because theres no rod to control a flapper.

You're right. I am confused, but not with blow off valves since I mentioned nothing about them.

Thanks for your comment. This is the part where I struggle to understand how it works.

So since there is no rod with an external wastegate, I am assuming there is no flapper on the turbo?

I looked at a diagram of an external wastegate. Theres a diaphragm and a spring. So boost pressure is built up inside the wastegate then exhaust gases are let through the wastegate to the exhaust once the wastegate spring compresses?

Something just came to my mind.. Does an external wastegate bolt onto a flange which is welded to the exhaust manifold or something?

Thank you for your informative comment.

You mentioned smooth linear boost with a wastegate (spring rate, etc), but... isn't this called boost creep? and don't people install boost controllers to avoid this and to exceed boost that the wastegate sees?

If my wastegate spring is 7lbs and my boost controller is set to 12psi, my flapper is going to open up rapidly... so what? I should get better spool up time and throttle response by not having any boost creep.

Once I get off the throttle, I'll drop from 12psi to 0 and the flapper will close. That shouldn't affect anything.

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feito

yes but you'll get some boost spike which is dangerous. Member since 05 ha?

2plus4plus0eq6

I might get boost spike you mean. I've heard lots of people say they have never experienced it no matter what kind of boost controller they used

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cotbu

What does that sound Like to you?
A waste gate? a waste gate doesn't need vacuum or the throttle plate closed to regulate boost! Think I lost some brain cells on that one.

I blame common core!

From a Highly Tuned Note 4.5!!!

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LoverTechnologies "Half Broken Things!"

Dboyizmlg

He's a noob, take it easy on the poor guy.

He is still learning basic boost principals.
We where all here at some point.

OP don't take it personal, we all get broken in when we enter the "Zilvia Realm"

Dboyizmlg

OP, Wait.... You been a member since 2005..? What in the....

Nevermind, disregard my last comment.

bmaddock

Great. Now you understand how a turbo works.

Wastegate controls the amount of exhaust flow the turbine sees and therefore the amount of compressed air the compressor produces.



How does it do that? By use of a vacuum source to the wastegate diaphragm where a tuned spring (7psi, 12psi, 16psi) than expels exhaust gases to slow the turbine and therefore regulate boost.

What does adding a boost controller do?



It adds a second, stiffer spring that "tricks" the wastegate spring to opening later (higher boost). EBC's than are just fancy versions of the MBC shown above.


If you have lazy noob questions after this I vote ban.

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derass

The valve of an internal wastegate is INTEGRATED with the turbine housing; whereas the valve of an external wastegate is (commonly) SEPERATE from the turbine housing. An external wastegate diverts the exhaust gas BEFORE the turbine. In most cases an EWG is located on the manifold but sometimes can be placed directly onto the turbine housing (Contradicting, I know). I think this diagram explains the concept pretty well.

2plus4plus0eq6

common core? not sure what that means..

I understand what you're saying. When I started this thread, I didn't quite realize an external wastegate was mounted onto the exhaust manifold or turbine to regulate boost.

bmaddock just said in his recent post that the wastegate needs a vacuum source and you're saying it doesn't. I thought it needs a boost source since the boost controller goes inline with it.....

I've been a member for awhile, but I had some important shit going on in my life which meant my car didn't see the road for years. I only got it back on the road in the last 5 months or so. Thats why I recently have been doing some research.

Thanks for noticing

Did you mean to say that the wastegate gets a boost source? not a vacuum source? When the boost controller goes inline with the wastegate, its called a boost controller, not a vacuum controller hah. right?

Thanks for your post. This is exactly where I need to get some more clarity. Correct me if my understanding here is wrong.

When a turbo has an internal wastegate, the flapper that is connected to the rod is what actually helps create the boost by holding in the pressure right? the spring inside the wastegate regulates the boost. Correct?

Now.. on a turbo with an external wastegate... how is boost created? is there a flapper still? There would be a massive boost leak without some kind of blockage to the turbine right?

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cotbu

You are learning!

I would excuse that statement, because I rarely ever ask for boost hose at the part stores.


From a Highly Tuned Note 4.5!!!

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LoverTechnologies "Half Broken Things!"