Wastegate Explained.

speed2horizon

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Jun 4, 2006
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small turbo boost 0.7 bar using big wastegate or small wastegate ?
what is the mm size suitable ?
and...
anyone low boost here 0.5~0.7bar using external wastegate ??
the dump pipe must use after using the external wastegate ??
how about internal wastegate? can use dump pipe too ?
hope can help !~
thankss !! 1 teh tarik for help
Theorethically, you should be using something bigger than 38mm... 44mm is better.
Theorethically, bigger sized wastegate is better for low boost wether ur turbo is big or small. But, bigger size wastegate is damn 97 expensive. So, u may think of getting the 38mm which are cheap and available everywhere...

Anyway, the effect won;t be so dramatic. There are tons of ppl boosting at 0.7bar with 38mm wastegate.

And boosting higher is going to materialize in your engine. It's the matter of time.
 

veilsideboyz

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Theorethically, you should be using something bigger than 38mm... 44mm is better.
Theorethically, bigger sized wastegate is better for low boost wether ur turbo is big or small. But, bigger size wastegate is damn 97 expensive. So, u may think of getting the 38mm which are cheap and available everywhere...

Anyway, the effect won;t be so dramatic. There are tons of ppl boosting at 0.7bar with 38mm wastegate.

And boosting higher is going to materialize in your engine. It's the matter of time.
ok !! Thankss you very much !!!:wavey:
I try find for 38mm wastegate and make a dump pipe after the external wastegate :)
 

veilsideboyz

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Theorethically, you should be using something bigger than 38mm... 44mm is better.
Theorethically, bigger sized wastegate is better for low boost wether ur turbo is big or small. But, bigger size wastegate is damn 97 expensive. So, u may think of getting the 38mm which are cheap and available everywhere...

Anyway, the effect won;t be so dramatic. There are tons of ppl boosting at 0.7bar with 38mm wastegate.

And boosting higher is going to materialize in your engine. It's the matter of time.
IF I can get 44mm wastegate with cheap .... that mean use 44mm wastegate better ??
:wavey:
 

speed2horizon

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IF I can get 44mm wastegate with cheap .... that mean use 44mm wastegate better ??
:wavey:
Better in terms of flow stability. That's what the book says. The book also say that the best position for wastegate is to be parallel with the turbo inlet via a Y joint on the exhaust manifold. And those set up can only be achieved with a faced down wastegate. As u can see from HKS exhaust manifold.

1) to reduce the effort of the exhaust to flow against the gravitational force.
2) Even flow distribution wbtween turbo and wastegate.
3) Less exhaust head loss dealing with corners and bends with faced up setting

But we can see tons of turbocharged car with wastegate pointed up nowadays when they open up their engine bay hood.

So, how much can we follow a book on a daily driven vehicle.

Just something to share here...
I read a book, the book says smoking is bad for health. I quit smoking.
I read abook, the book says drinking is bad for health. I quit drinking.
I read a book, the book says SEX is bad for health. And I quit reading...
 

chrissyong

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use small turbo want hi boost use small waste gate,if want use bigger turbo hi boost also need small waste gate,if want use small turbo low boost need bigger waste gate,if bigger turbo want low boost need bigger waste gate......:smokin:
 

kelvins3281

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Reading bout sex is bad for health on book then quit reading..haha...interesting...:rofl::rofl::rofl:

---------- Post added at 08:19 AM ---------- Previous post was at 08:16 AM ----------

use small turbo want hi boost use small waste gate,if want use bigger turbo hi boost also need small waste gate,if want use small turbo low boost need bigger waste gate,if bigger turbo want low boost need bigger waste gate......:smokin:
Just like hi boost small wgate low boost big wgate.
correct me if i'm wrong.:confused:
 

speed2horizon

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Wastegates - Facts and Fiction


With so many contradicting opinions and recommendations, it’s a little wonder choosing the right Wastegate for your application can be a confusing.
We try to disspell some myths and shed some light on the most common misconceptions regarding wastegates.


TRUE OR FALSE
*The more powerful the engine, the bigger the
wastegate you need.*
False. This is one of the more popular misconceptions. A wastegate is possibly the only component in your whole engine package that can actually be made smaller as you increase your boost/horsepower output. Use this simple guide:
Big Turbo/Low Boost = Bigger Wastegate
Big Turbo/High Boost = Smaller Wastegate
Small Turbo/High Boost = Smaller Wastegate
Small Turbo/Low Boost = Bigger Wastegate

Wastegates don’t operate in high temperatures.
False. Contrary to the popular belief, external wastegates are usually mounted at the hottest part of the exhaust. It’s the place where all the exhaust gases meet, creating extra heat. This, combined with the late combustion of unburnt fuel (due to rich mixtures, retarded timing and high octane fuels) significantly raises the exhaust temperature.


Larger wastegate valve diameter = better flow.
True – sort of. While the valve diameter is without a doubt an important part of the flow rate, equally important, but often misunderstood, is the importance of the flow path. When comparing wastegates with similar valve size, it is important to have a balanced body/valve/spring combination that is designed to work together to allow for maximum boost control. All Turbosmart wastegates are designed with this in mind.


(*article courtesy of Turbosmart) :smokin:
READ SDF THREAD AGAIN...

use small turbo want hi boost use small waste gate,if want use bigger turbo hi boost also need small waste gate,if want use small turbo low boost need bigger waste gate,if bigger turbo want low boost need bigger waste gate......:smokin:
YEAH... THAT"S RIGHT...

Reading bout sex is bad for health on book then quit reading..haha...interesting...:rofl::rofl::rofl:

---------- Post added at 08:19 AM ---------- Previous post was at 08:16 AM ----------



Just like hi boost small wgate low boost big wgate.
correct me if i'm wrong.:confused:
YEAH.... U GOT IT....

THAT's HOW IT SUPPOSE TO BE...

However, Big wastegates are more expensive compare to Small diameter wastegates. Like said, there are tons of theory proven in the automotive world. However, there are theory that are critical and non critical...

Theorethically, BOV is not so reliable for car using MAF. Well, I think 95% of EVOs having BOV instead of BIV/BYPASS VALVE....

So, there are 2 millions cause of power lost on the road... Haihz... Too much to consider... Improper Wastegates' size, still perform better and more reliable than internals anyway...

But if it's a race machine I'm building.... Then I'll reduce as much obstacles as possible... Still... refering to my budget...

Just my 2 cents opinion...
 

veilsideboyz

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use small turbo want hi boost use small waste gate,if want use bigger turbo hi boost also need small waste gate,if want use small turbo low boost need bigger waste gate,if bigger turbo want low boost need bigger waste gate......:smokin:
Thankss Bro !! :D
Hmm...
how many psi consider low ?? 0.7bar or below 1 bar ?
And...I have some confuse here....
High boost = Small wastegate
Low boost = Big wastegate...
but...why a lot people low boost but still using 38mm wastegate ??
I thought 38mm wastegate consider small ??? above 44mm wastegate only consider big right ?
if not mistaken :hmmmm:
 

speed2horizon

2,000 RPM
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Jun 4, 2006
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Thankss Bro !! :D
Hmm...
how many psi consider low ?? 0.7bar or below 1 bar ?
And...I have some confuse here....
High boost = Small wastegate
Low boost = Big wastegate...
but...why a lot people low boost but still using 38mm wastegate ??
I thought 38mm wastegate consider small ??? above 44mm wastegate only consider big right ?
if not mistaken :hmmmm:
That's right.
Simple explanation. 38mm are much cheaper compare to 45mm wastegates. Most of the low booster are new to turbo engines. They may not willingly spend big amount for something they will upgrade in future. So, they may as well use a 38mm. So, when they upboost, they needn't to upgrade hardware and spend another amount of money.
 

veilsideboyz

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Oct 28, 2008
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That's right.
Simple explanation. 38mm are much cheaper compare to 45mm wastegates. Most of the low booster are new to turbo engines. They may not willingly spend big amount for something they will upgrade in future. So, they may as well use a 38mm. So, when they upboost, they needn't to upgrade hardware and spend another amount of money.
ok ! Thankss you so much !!:wavey:
Learn some new experience here :)
 

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