Choosing a wastegate??
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Choosing a wastegate??
Just browsing the tial site... Do wastegates have a power limit? How do you decide what size gate to use? Does it go by how much boost you are building? or how much power? or what? Will a 35mm be to small for big boost/power?
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Re: Choosing a wastegate??
The theory is that a larger wastegate (44 mm) should be utilized on turbos using low boost vs. turbos that are running high boost which should run a smaller wastegate (38 mm). Where did this theory come from? Remember…a wastegate limits boost. If you want to run more boost, you don’t have to limit it as much. Running less boost means you have to limit it more. Think this premise through to get a good mental picture of it as this concept is terribly misunderstood.
If you are going to be in the low teens for boost than a 38mm should be fine. Any more than that than you should get a 44mm. If your WG is not big enough then boost creep and spiking can start. Thsi is because the smaller WG can't expel the excess manifold pressure created.
If you are going to be in the low teens for boost than a 38mm should be fine. Any more than that than you should get a 44mm. If your WG is not big enough then boost creep and spiking can start. Thsi is because the smaller WG can't expel the excess manifold pressure created.
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Re: Choosing a wastegate??
The larger the turbine, ex. housing, or exhaust, or freer-flowing the manifold, the larger the WG needed to run lower boost. More HP = faster turbo speed = less gas dumped through the WG.
Below 10psi many typical b-series will have slight boost creep (raises near redline) issues with a 35mm WG, some with a 38mm, and almost none with a 44mm.
btw 20psi isn't low boost, it's just YOUR low-boost setting.
Below 10psi many typical b-series will have slight boost creep (raises near redline) issues with a 35mm WG, some with a 38mm, and almost none with a 44mm.
btw 20psi isn't low boost, it's just YOUR low-boost setting.
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Re: Choosing a wastegate??
I guess thats a thought to since i do have one 38 already.... cool guys, thanks for explaining the theory to me.. i guess i shouldve known because now it just seems like common knowledge to me!
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Re: Choosing a wastegate??
depending on the manifold design and turbo choice will also change the wg size your going to need. some people are having hard time controlling low boost when there running the gt35r turbo with up to 44mm wastegate on a ramhorn style manifold. now a very similar turbo is the sc6152s and its not as bad because of a different turbine wheel and not being ball bearing. I personally am running a 38mm wg and it controlls low boost 9 psi just as easy as 20 psi. on a cast spa top mount and a big turbine wheel with .82 hotside
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Re: Choosing a wastegate??
The larger the turbine, ex. housing, or exhaust, or freer-flowing the manifold, the larger the WG needed to run lower boost. More HP = faster turbo speed = less gas dumped through the WG.
Below 10psi many typical b-series will have slight boost creep (raises near redline) issues with a 35mm WG, some with a 38mm, and almost none with a 44mm.
btw 20psi isn't low boost, it's just YOUR low-boost setting.
Below 10psi many typical b-series will have slight boost creep (raises near redline) issues with a 35mm WG, some with a 38mm, and almost none with a 44mm.
btw 20psi isn't low boost, it's just YOUR low-boost setting.
the trick has always been for the street/strip guys. Those that want lower boost for "street use", then "occasionally take it to the drag strip" when they want to run higher boost levels. Depending upon the use of the car and the power level (from the turbo choice used) is where the correct gate can be used. Many people here go by the Larger gates because of this dual duty of the turbo.
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Re: Choosing a wastegate??
high boost doesnt always mean the need for a big gate. you could run 40 lbs on a 42r and still have a 38mm gate regulate it well.
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