Honda / Acura K20a K24a Engine Forum banner

1 - 20 of 26 Posts

·
Registered
Joined
·
788 Posts
Discussion Starter #1
i got into a heated discussion with my father at dinner the other night becouse neither of us really understand how the idea of dual waste gates works. ive been told it creates smother boost but i dont really understand how. so if someone could give a good explanation of how it works i would much apreciate that! thanks!
 

·
treblictuned
Joined
·
1,422 Posts
the point of dual gates is for better boost control
 

·
treblictuned
Joined
·
1,422 Posts
dual gates flow more exhaust than a single gate, therefor it shouldnt boost creep as bad and allowing better control of boost via boost controller
 

·
Registered
Joined
·
3,120 Posts
Its not that dual wg flows more exhasut gases than a single wg.

Dual wg is used when you use a twin scroll turbo with a divided flange. The divided housing keeps the gases from the two sides separate so it will built faster boost.

Then you use the dual wg to dump the exhaust gases and hold boost what you want it. So you use one wg from each side of the collector, that way you don't allow the gases to mix.
 

·
treblictuned
Joined
·
1,422 Posts
Its not that dual wg flows more exhasut gases than a single wg.

Dual wg is used when you use a twin scroll turbo with a divided flange. The divided housing keeps the gases from the two sides separate so it will built faster boost.

Then you use the dual wg to dump the exhaust gases and hold boost what you want it. So you use one wg from each side of the collector, that way you don't allow the gases to mix.
same shit..was trying to put it in laymon terms... :p
 

·
Premium Member
Joined
·
1,851 Posts
i got into a heated discussion with my father at dinner the other night becouse neither of us really understand how the idea of dual waste gates works. ive been told it creates smother boost but i dont really understand how. so if someone could give a good explanation of how it works i would much apreciate that! thanks!
I must say it is AWESOME that you and your dad talk about wastegates over dinner:up::up:
 

·
Registered
Joined
·
3,120 Posts
same shit..was trying to put it in laymon terms... :p
Its not "same shit"

its the fact that you need to keep the two colectors from sharing exhaust gases.
 

·
Registered
Joined
·
1,175 Posts
Its not "same shit"

its the fact that you need to keep the two colectors from sharing exhaust gases.

what your saying doesnt really make sense my man. what 4 cylinder engine have you ever seen that had 2 collectors? the wastegates are before the turbo of course , so how do they individuate sides of a split flange T4 turbo?. all the top money manifolds ive seen , the wastegate ports exit the collector , meaning the exhaust from all 4 cylinders is mixing before the wastegates and turbo , regardless if its split flanged. all the exhaust has to mix together before the turbo , has to be that way. dual wastegates are to prevent boost creep and allow better boost control when a single wastegates efficiency is outdone , simple. why make it complicated. bluehatch's descripton was right on the money. if an engine is putting out a mad amount of exhaust , one wastegate cant let it out fast enough and it builds up in the manifold/turbo causing boost creep.


if you were to have a sidewinder or tube manifold period that went 4 into 2 with a wastegate on each one of the 2 , than 2 into your turbo flange , i could see what your saying somewhat. but even if you did this , all the exhaust is still mixing before the turbo.
 

·
Registered
Joined
·
477 Posts
what your saying doesnt really make sense my man. what 4 cylinder engine have you ever seen that had 2 collectors? the wastegates are before the turbo of course , so how do they individuate sides of a split flange T4 turbo?. all the top money manifolds ive seen , the wastegate ports exit the collector , meaning the exhaust from all 4 cylinders is mixing before the wastegates and turbo , regardless if its split flanged. all the exhaust has to mix together before the turbo , has to be that way. dual wastegates are to prevent boost creep and allow better boost control when a single wastegates efficiency is outdone , simple. why make it complicated. bluehatch's descripton was right on the money. if an engine is putting out a mad amount of exhaust , one wastegate cant let it out fast enough and it builds up in the manifold/turbo causing boost creep.


if you were to have a sidewinder or tube manifold period that went 4 into 2 with a wastegate on each one of the 2 , than 2 into your turbo flange , i could see what your saying somewhat. but even if you did this , all the exhaust is still mixing before the turbo.
This is about as top money as top money desires.

 

·
Registered
Joined
·
238 Posts
^^^that's exactly the pic i was thinking of when i read the original post. the only time i've seen dual wastegates was with that manifold on a 800whp+ b series.
 

·
Registered
Joined
·
788 Posts
Discussion Starter #14
thanks for all the info everyone! i am going to order a full race kit on friday... im still decideing on the wastegate setup yet but at least now i can make the right decision!
 

·
Registered
Joined
·
3,120 Posts
what your saying doesnt really make sense my man. what 4 cylinder engine have you ever seen that had 2 collectors? the wastegates are before the turbo of course , so how do they individuate sides of a split flange T4 turbo?. all the top money manifolds ive seen , the wastegate ports exit the collector , meaning the exhaust from all 4 cylinders is mixing before the wastegates and turbo , regardless if its split flanged. all the exhaust has to mix together before the turbo , has to be that way. dual wastegates are to prevent boost creep and allow better boost control when a single wastegates efficiency is outdone , simple. why make it complicated. bluehatch's descripton was right on the money. if an engine is putting out a mad amount of exhaust , one wastegate cant let it out fast enough and it builds up in the manifold/turbo causing boost creep.


if you were to have a sidewinder or tube manifold period that went 4 into 2 with a wastegate on each one of the 2 , than 2 into your turbo flange , i could see what your saying somewhat. but even if you did this , all the exhaust is still mixing before the turbo.

If it doesent make sence then you have no clue how the twin scroll manifolds are designed.

The twin scroll manifolds have two 2-1 collectors. It looks like a 4-1 but there are actually two collector that are separate from each other.

Look inside the exhaust housing of a twin scroll turbo. You will see that the housing is divided all the way to the turbine. So none of the gases will mix untill they hit the trubine blades.



So no need to tell me how this shit works.

But if you don't want to listen then have it your way.

This is prime example why I stop posting in some of these posts.
 

·
Registered
Joined
·
1,175 Posts
dude , dont get all bent out of shape , in no way did i mean you didnt know what your talking about. iv been around this site long enough to know you very much do. i just didnt understand and wanted you to elaborate , discussion. what your saying is , the collector has a wall inside and in between the 4 pipes gathering. in essence making it like i said , 4-2 , wastegates , and the 2-1 is the turbo itself. i get ya. sorry if i pissed ya off man , wasnt my goal at all. when you said 2 collectors it threw me for a loop.

what exactly is the benefit of this setup over non divided turbine housing and 2 wastegates out of a non split collector? just spools faster or?
 

·
Premium Member
Joined
·
1,821 Posts
dude , dont get all bent out of shape , in no way did i mean you didnt know what your talking about. iv been around this site long enough to know you very much do. i just didnt understand and wanted you to elaborate , discussion. what your saying is , the collector has a wall inside and in between the 4 pipes gathering. in essence making it like i said , 4-2 , wastegates , and the 2-1 is the turbo itself. i get ya. sorry if i pissed ya off man , wasnt my goal at all. when you said 2 collectors it threw me for a loop.

what exactly is the benefit of this setup over non divided turbine housing and 2 wastegates out of a non split collector? just spools faster or?
Generally speaking, a twin scroll turbo comes with a divided turbo inlet (like the one onefstek posted the picture of) to isolate the pulses coming from each exhaust port to maintain more of the pulse energy from each cylinder all the way down to the turbine wheel. A twin scroll setup will respond faster and produce boost quicker than a regular turbo. Twin scroll setups are generally costlier and require more components than the average turbo upgrade to work effeciently though.
 

·
Registered
Joined
·
390 Posts
Dual wastegates are not only for Twin Scroll setups. They help control boost in all applications.

If your turbine/wheel/housing setup is very efficient and depending on the priority of your turbo manifold sometimes one wastegate simply is not enough.

Priority meaning does the manifold flow into the wastegate 1st or directly into the turbo.

Example Hytechs Bseries Manifold vs Standard Ramhorn setup.
 

·
Registered
Joined
·
3,120 Posts
Dual wastegates are not only for Twin Scroll setups. They help control boost in all applications.

If your turbine/wheel/housing setup is very efficient and depending on the priority of your turbo manifold sometimes one wastegate simply is not enough.

Priority meaning does the manifold flow into the wastegate 1st or directly into the turbo.

Example Hytechs Bseries Manifold vs Standard Ramhorn setup.
Yes you can use it for controlling boost in applications where one wg is not enough. But you are talking on cars that make serious hp.

If the wg is placed at the right angle in the collector, then you should have no problem controlling boost with a single 40mm wg.

My old B series set up made 640 whp/420 wtq on pump gas with no boost creep issues, using single 40mm tial wg.
 

·
Registered
Joined
·
390 Posts
Yes you can use it for controlling boost in applications where one wg is not enough. But you are talking on cars that make serious hp.

If the wg is placed at the right angle in the collector, then you should have no problem controlling boost with a single 40mm wg.

My old B series set up made 640 whp/420 wtq on pump gas with no boost creep issues, using single 40mm tial wg.
I think it all depends on the application.

My old street b-series setup was a full race manifold with t3/67 turbo. It would not hold boost lower then 15psi. I had them attach another wastegate on and I was able to hold 7-8psi which was perfect for finding traction. This was a single scroll setup.

But I agree, it depends on the manifold design. I had a Lovefab manifold that had wastegate priority and it held boost fine with a single scroll setup.
 
1 - 20 of 26 Posts
Top