Recirculated WasteGate vs Open WasteGate?

7mgte1988

7M-Runner
Sep 22, 2008
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Orlando
Thats strange what is it recirculating too??
I was always told if u have an open wastgate its alot louder..like having a hole in the header at WOT..
 

turbo87targa

New Member
Nov 10, 2006
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colorado springs
7mgte1988;1375742 said:
Thats strange what is it recirculating too??
I was always told if u have an open wastgate its alot louder..like having a hole in the header at WOT..

he means when the wastegate dump tube goes straight to the atmosphere or when its recirculated back into the downpipe farther down.
 

sethron71

Authorized Vendor
Jul 19, 2005
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Hey Manny,
Where does yours recirce back in? I know that if it does not join very gradually/at a shallow angle it can cause turbulance and excess back pressure hurting spool. It is best to recirce it into the bend at the bottom of the DP so you can have the gasses flowing right with flow as they enter. Obviously there is a drastic difference in noise as I am sure you already know!

So what are you doing? 3.5" or 4" DP? New wastegate with good spring finally? lol

HTH,
Seth
 

JPsToyota

Member
Sep 17, 2008
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I've always been under the impression that a properly made open dump will always be a bit stronger than directing it into the exhaust. It just kind of makes logical sense when thinking about the exhaust.

Make sure you are dumping it away from things that dont like fire.
 

Boosted Supra

AEM 7MGTE 6765
Apr 7, 2005
353
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Valley Stream, New York, United States
LOL Seth. My w/g is actually connected like this

p1375828_1.jpg

p1375828_2.jpg


I'm sticking with the same setup, no looking to spend extra $$$ when what I have is good and plenty, lol.
 
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Poodles

I play with fire
Jul 22, 2006
16,757
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Fort Worth, TX
Backpressure doesn't exist (you DON'T want figgie to bitchslap you).

As the WG is there to LIMIT power, it really doesn't matter too much on how it enters the rest of the exhaust.

After owning a DDP for a number of years, I have grown to hate it most of the time, but love it some of the time. It will be changed eventually...
 

dumbo

Supramania Contributor
Jul 16, 2008
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Poodles;1376029 said:
Backpressure doesn't exist (you DON'T want figgie to bitchslap you).

As the WG is there to LIMIT power, it really doesn't matter too much on how it enters the rest of the exhaust.

After owning a DDP for a number of years, I have grown to hate it most of the time, but love it some of the time. It will be changed eventually...

Backpressure DOES exist, you just don't want it on turbocharged engine, as the pressure differential goes down, so does turbo response.
 

91TURBOSUPRA

New Member
Apr 2, 2005
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hey manny wats up well you heard my open wastegate at the ne2k9 meet.... and if you dont mind the noise then i would go for it in my opinion...
pros: more power, you can scare people lol.
cons: noise smell but not really if you route the dump tube in the right direction
 

Poodles

I play with fire
Jul 22, 2006
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No, backpressure does not exist ;) Don't make me page figgie...

Personally I'd rather go rerouted with a cutout if I want the noise, but I don't forsee myself doing that.
 

dumbo

Supramania Contributor
Jul 16, 2008
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Poodles;1376266 said:
No, backpressure does not exist ;) Don't make me page figgie...

Personally I'd rather go rerouted with a cutout if I want the noise, but I don't forsee myself doing that.

http://en.wikipedia.org/wiki/Back_pressure

It does. We just don't want it;) Thats why people run open WG(Even though it sounds like a jet when the WG opens). And run
3",4" exhaust and beyond for high hp turbo engines.
 

Enraged

A HG job took HOW long??
Mar 30, 2005
1,844
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Victoria, BC, Canada
:: facepalm :: wikipedia is NOT a good way to back up your argument.

and as poodles says, it's not backpressure, its exhaust flow. when people say something increases backpressure, what it ACTUALLY means is a restriction in flow.

if you still don't believe me, go take a mechanical engineering course.

"backpressure" is to fluid dynamics as "centrifical/centrifugal force" is to physics.
 

shaeff

Kurt is FTMFW x2!!!!
Staff member
Super Moderator
Mar 30, 2005
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Waiting for figgie. LOL.

We need a bat signal for him!
 

sethron71

Authorized Vendor
Jul 19, 2005
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www.SethIngham.com
Hey Manny,
Yea you might find minimal gain in figuring out a way to get the angle of entry not so sharp as it is 90 degrees now and can cause turbulance in the flow.

As for the back pressure issue why does a 4" DP help spool? Less back pressure on the turbine blade so in theory if the WG is causing turbulance which causes some back pressure on the turbine it could hurt boost.

With that said seeing the numbers you are making it is not hurting you too much ;)

Seth
 

IJ.

Grumpy Old Man
Mar 30, 2005
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JPsToyota;1375813 said:
I've always been under the impression that a properly made open dump will always be a bit stronger than directing it into the exhaust. It just kind of makes logical sense when thinking about the exhaust.

Make sure you are dumping it away from things that dont like fire.

Only if the rest of the exhaust is restrictive.

As for "back pressure" it's just a term used to describe a restriction in flow ie: 4" dump into a 2.5" system with mufflers, where it becomes an issue is when you have ex manifold pressures = to or greater than intake pressure in a turbo motor.