# Open Dump v.s. Recirculated Dump - Power Gains??



## eurobred (Jun 10, 2005)

did a search on this, skimmed through threads dated all the way back to 2002... 
still found no solid answer... 

what are the benefits of running an open dump v.s. recirculating it back into the DP? 
aside from it being loud at full boost, are there any extra ponies gained? 

i know for any forced induction setup, generally, the faster air can enter, and the faster the exhaust is able to exit, the more power you make. 

but for you who have done both, i'd like to hear your info. 
currently my dump is recirculated back into the DP. 
thinking about changing.


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## FaelinGL (Nov 28, 2004)

You will definitely gain a few ponies. Here is a dyno graph of my car, WG to atmo. Tell me when the WG opens =) Plus, I love the sound. 










Mike


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## eurobred (Jun 10, 2005)

yea the sound is beautiful. some people say they get tired of it. but i doubt i will. 

looks like it opens around the 4600+RPM range. i can see the spike in power. 

nice :thumbup::thumbup:


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## toy_vw (Feb 11, 2006)

ive been in cars with both....other then noise...no difference...think about it...once the wastegate open's...the boost doesnt get any higher...and all the exhaust is mostlikely exiting through a 1inch pipe....but...I did put a sticker on my car and that gave me 33 Whp


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## GinsterMan98 (May 19, 2008)

I think you will see the biggest gain if you have a small exhaust. If you are running an exhaust that is adequate for your setup I think you won't see much of a gain. Also, the more boost you run less gas is vented via the wg, so you would also see gains if your on a low boost setup as it is venting more through the wg.


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## huichox4 (Nov 8, 2004)

It helps with even flow in the exhaust and reduce turbulence. open dump is like having a bigger downpipe once the wastegate opens. all the gas that goes through it dont occupy space in your actual exhaust so its less restricted in that sense. your goal is to get rid of all the exhaust as quick as possible so having two streams of gasses come together in one without opening up the area is not the best in my opinion.


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## GinsterMan98 (May 19, 2008)

yeah ^^^ what he said.


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## ValveCoverGasket (Mar 20, 2002)

its all about the pressure differential across the turbine... 
as mentioned it will create some more "restriction" in the exhaust if those gases have to join up again down stream. granted how much restriction will vary a lot depending on how far down, at what angle, etc


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## girdwood (Mar 10, 2004)

What all is required to make it an open dump? I'm currently running a recirc system (via 40mm TiAL external on a T3/4 50 trim .48), and my waste-gate pipe is horribly made, planning on fixing it this weekend, might as well do this at the same time. I'm new to turbo setups, be gentle, and forgive my ignorance..


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## Svedka (Jul 4, 2008)

You can see on mine it just goes down that's what I decided to try out I'll reroute it to the DP if I don't like it :laugh:


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## huichox4 (Nov 8, 2004)

rollercoasterracer said:


> What all is required to make it an open dump? I'm currently running a recirc system (via 40mm TiAL external on a T3/4 50 trim .48), and my waste-gate pipe is horribly made, planning on fixing it this weekend, might as well do this at the same time. I'm new to turbo setups, be gentle, and forgive my ignorance..


 cut the pipe that goes from the wastegate to the downpipe, make it a nice and flush cut and then weld shut the hole it will leave in the downpipe. 

then you may want to use the flange that connects to the wastegate from the pipe you just removed and use it for your new dump tube, which is nothing less than a 38mm or 44mm or whatever diameter wastegate size you have routed straight down to the ground and that is it. 



Unless you have an internal wastegate :sly:


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## ValveCoverGasket (Mar 20, 2002)

rollercoasterracer said:


> What all is required to make it an open dump? I'm currently running a recirc system (via 40mm TiAL external on a T3/4 50 trim .48), and my waste-gate pipe is horribly made, planning on fixing it this weekend, might as well do this at the same time. I'm new to turbo setups, be gentle, and forgive my ignorance..


 
just block off the downpipe where they meet up, and route the wastegate outlet plumbing down to somewhere near the bottom of the car (i prefer somewhere around the subframe, below the steering rack so the exhaust isnt burning anything up) 

heres the downpipe and the dump tube from my gti....


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## vwturbofox (Jul 31, 2010)

I love the sound of my 38mm tial dumped.scares the crap out of people when it hits full boost


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## idntnowhtimdoin (Jun 3, 2010)

I think on anything but a very very highly tuned car you arent really going to notice a difference unless you have a horrible re entry from the WG... I have Kinetics 2.5dp the WG enters just before the flex pipe about a foot before the end of the downpipe then it becomes a full 3" exhaust system. I MIGHT gain 2-300rpm worth of spool time if to atmosphere but I think thats on the generous end. 

Also mr dyno chart above. You said you have more power with a dump then without? so wheres the recirc dyno chart? every large/slow spool car looks like that on a dyno....


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