Please explain dif between Internal & External gate

[Abo Bob]

Could someone please explain the difference between an internal and external wastegate?

I'd like to know the advantages and disadvantages.

Pics would be nice.

Thanks.

[B-Man]

See this turbo housing ? This is the exhaust side

See the little circular flap and actuator arm - this and example of an internal or integral wastegate - In other words, it's integrated into the exhaust housing

Here's another pic of a housing with an internal gate

Internally gated turbo's require an actuator to open the gate:

This next pic is an example of a turbo with an external gate

The wastegate is mounted on the exhaust manifold.

Here's another

The actuator is built into the external gate.

[ed]

And I believe external gates control boost better?

they also cost a fair whack too (external gates)

[Guest RedLineGTR]

Thanks B-Man

[B-Man]

A wastegated turbocharger includes an integral device to limit turbo boost. This consists of a pneumatic actuator connected to a valve assembly mounted inside the turbine housing. By connecting the pneumatic actuator to boost pressure, the turbo is able to limit its maximum boost output. The net result is increased durability, quicker time to boost, and adjustability of boost.

[B-Man]

More good info here:

http://www.atpturbo.com/root/technicinfo/gendef.htm

http://www.turbofast.com.au/

[B-Man]

What's the difference between internal and external wastegates?

Internal wastegates are comprised of a flapper door which is built in the turbine housing, usually operated pneumatically by a mechanical actuator. These flapper doors are limited in size, but work well in certain applications. Usually found in smaller turbos, internal wastegates are relatively inexpensive, simple in design, and very durable. Larger turbo can be fitted with internal wastegates, but boost control can be tricky. If you are looking to run high boost (20+ psi) all the time, then an internal gate may be fine. If you are looking to run lower boost levels, you will need an external wastegate.

External wastegates are generally mounted to the exhaust manifold or to the O2 housing, and are self contained units. External wastegates have the ability to bypass large amounts of air, and can provide steady boost control at any pressure level. A common myth is that in order to run higher boost pressures, you need a larger wastegate. This is incorrect. Larger wastegates are necessary to run low boost levels on large turbos.

[AssM@N]

cool - i didn't know the diff before aswell1

thanks B-man, great stuff there

[AssM@N]

What's the difference between internal and external wastegates?

A common myth is that in order to run higher boost pressures, you need a larger wastegate. This is incorrect. Larger wastegates are necessary to run low boost levels on large turbos.

so would it hurt to put a large waste gate on a small turbo?

[Scooby]

Thanks B-Man, excellent.

[T0nyGTSt]

The problem with ext. wastegates is COST and SIZE.

A GT-R cannot usually run ext. wastegates unless it's a single conversion.

You also need the cost if manifold, gate + usually dump pipe.

+ injectors, ECU, boost, etc. etc.

T.

[Abo Bob]

Ah so. Thank you very much. So much talk goes on in these forums about details but sometimes us newbies haven't got the basics sorted.

[benm]

Ditto Abo.

Thanks B-Man

Is their a recommended brand/model or are all the Japanese brands similar in quality/performance ?

[T0nyGTSt]

One thing is that large high mount external gate turbos are hardly stealth installs.

Pop the bonnet and everyone, esp. cops will know the car is 'off its teats'.

Also I note that many people love the high mounts and big gates so that they can run a screamer pipe that is also illegal.

But to make serious hp - say around 300rwkW, you pretty much need an external gate system.

T.

[B-Man]

Ditto Abo.

Thanks B-Man

Is their a recommended brand/model or are all the Japanese brands similar in quality/performance ?

Ben, I have never heard a bad report on the performance of an external gate - they are pretty simple devices. (yet expensive)

Known Brands are:

Trust / GReddy

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