what is a waste gate

[ncsdaonex]

i am going to make a turbo exhaust manifold and i need to know what a waste gate is and what it does and how it works, ive checked and looked into it but i cant find any good information on it

 

[Wicked_Sludge]

a waste gate is a valve that diverts exhaust gas from the turbo to limit the level of boost.

no offense, but your trying to build a turbo system and you dont even know what a waste gate is? you seem to be in a little over your head....

 

[ncsdaonex]

waste gate

a waste gate is a valve that diverts exhaust gas from the turbo to limit the level of boost.

no offense, but your trying to build a turbo system and you dont even know what a waste gate is? you seem to be in a little over your head....

no, i did my research for the most part and i understand about 90 percent what im doing and whats involved its just everyone i asked about the waste gate couldnt give me a good definition so thanks, now i know what it is

 

[turbo cat]

alot of oem turbocahrgers have wastegates in gasoline applications. tehse are called internal wastegates. The aftermarket wastegates that can be welded intop the exhaust anywhere before the turbo is called a external wastegate. A internal gate is a valve attached to a arm that is attached to a diaphram/spring. As the "can" sees what pressure its tension is set for thru the vaccum line that is plugged into the compressor outlet it will begin to open. Then open and close at different lifts to regulate and maintain a steady max boost pressure.

 

[crbnunit]

You can modify most wastegates to be adjustable. Meaning you can dial in the amount of boost you want to produce. Be very careful and conservative if you do this as you can cause som emajor internal engine damage by cranking out too much!

 

[Will]

a waste gate is a valve that diverts exhaust gas from the turbo to limit the level of boost.

no offense, but your trying to build a turbo system and you dont even know what a waste gate is? you seem to be in a little over your head....

Are you saying he shouldn't try anything unless he knows everything about it?

It's possible to size a turbo so you don't need a wastegate. The diesel in my bus is aftercooled, runs 20psi and has no wastegate. The diesel in my pickup is not aftercooled, runs 12psi and has no wastegate. The wastegate is there so you don't overspeed the turbo. If you want more low-rpm boost you have to run a smaller turbo so it spools up quickly, then it needs to be wastegated so it doesn't pop like a corn kernel.

 

[turbo cat]

yes on a gasoline setup you need generally need a wastegate however if the turbine housing is large enough you cant overspin the turbo. On diesel setups the housings are size sometimes overly large. Some diesel setups have wastegates soem do not. if the turbine housings is large enough it dosent need a wasteage becasue you cant overspin the turbo.

 

[shadetree]

It's possible to size a turbo so you don't need a wastegate. The diesel in my bus is aftercooled, runs 20psi and has no wastegate. The diesel in my pickup is not aftercooled, runs 12psi and has no wastegate.

Yes, but diesels are different animals. They do not regulate air flow like a gasoline engine, only fuel flow.

The wastegate is there so you don't overspeed the turbo. If you want more low-rpm boost you have to run a smaller turbo so it spools up quickly, then it needs to be wastegated so it doesn't pop like a corn kernel.

A turbo will "self-regulate" at a certain point. When it is pumping max, the friction will not allow the impeller to spin any faster. It can also cause the compressed air to overheat. I have never seen a turbo "pop," but I have seen them blow hoses, and bend impeller blades during backfire.shady

 

[turbo cat]

diesels still move alot of air. On soem appliction liek the early cummins 5.9Ls they have no wastegate as teh exhaust housings are 18cm or 21 cm in 94 the 5.9L setup got a 12cm housing which needed boost control and a wastegate was added due to the tiny housing