Internal or External wastegate, which is better?

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Big P
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Internal or External wastegate, which is better?

Post by Big P »

Hey guys, as I have been doing some more research on my turbo project, I have come across two types of turbo wastegates, internal and external. Which one is better? I would like for the wastegate that I get to be adjustable from inside the car. So what are the pros and cons to both? Thanks, Paul Moore
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PrecisionBoost
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Post by PrecisionBoost »

External wastegate is allways better.... what turbo are you using?

Many factory systems use internal wastegates to save on space and minimize cost.

The ideal setup is a very smooth transition pipe integrated into the exhaust manifold leading to a large wastegate which then has a long pipe which smoothly interfaces with the exhaust several feet below the turbo.

This is ideal..... but sometimes it's hard to find the space to make it work good.

Most wastegates clamp right on to the manifold.... which isn't the ideal setup but it makes the cost of the installation cheaper and saves on room.

An external wastegate clamped directly onto the manifold will be more efficent than an internal typically but the external type where there are smooth transitions are the best
Last edited by PrecisionBoost on Thu Sep 01, 2005 8:25 pm, edited 1 time in total.
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Post by Audacity Racing »

i don't think external is always better...



the turbo flow is better and thus effeciency is higher...


but there is excessive weight and common manifold weld/tube failure when using external gates. another issue is the size of an external. most internals are small and don't add much over-all mass to the turbo setup.



my $0.02
Stefan
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Post by Stefan »

From your other posts it seems your car will see strip action. An external wastegate would be the best for this. A properly designed and sized external wastegate system will give the best boost control. For traction off the line boost control is very important. Combine the external wastegate with an electronic boost controller so you can limit boost in the lower gears, you should be able to get pretty good 0-60ft times.
You'll also get much better control of your maximum boost level with less chance of creep etc.

Speak to wastegate manufacturers about your target hp level, application and type of manifold design and they should recommend a wastegate size to suit.
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debo890
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Post by debo890 »

external = done right( with smooth flow like erfinder said)
internal = oem's method of saving money(an accounts decision).
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