wategate/down pipe

[justinhill98gst]

long story short, right now im running the wastegate back into the exhaust but the down pipe broke again so im gonna make a new down pipe. My question is, Is it better to let the waste gate release in the exhaust or atmosphere?

 

[dSmgs-T]

personal preference, and state law/emissions

 

[cruisintalonawd]

I would say if your having problems with boost spike/creep the I would external dump it but if your not then put it back into the exhaust

 

[1992awdlaser]

Buschur has proven that you will most likely gain power and decrease the time it takes to hit full boost if you dump to the atmosphere. When it is recirculated it creates turbulance which decreases the power and increases the time it takes to spool. It can be recirculated so that there is almost no difference, but it is pretty hard to get the perfect angle going back into the exhaust and making the dump tube smooth all the way from the gate to where it enters the exhaust.

To me, the only reason to reciculate is if you don't want to deal with the noise when at boost or state laws. On some setups the exhaust or other things are louder than the wastegate though.

 

[Supa Dexta]

I believe it's been shown to pick up 12-15hp being dumped. Some people can't handle the volume though, or can't get away with it locally.

 

[justinhill98gst]

Well, i have a down pipe that was going back in the exhaust but do day it just broke in half and the shop that made it shut down so now i was just gonna make a new one.

 

[kahl23]

Buschur has proven that you will most likely gain power and decrease the time it takes to hit full boost if you dump to the atmosphere. When it is recirculated it creates turbulance which decreases the power and increases the time it takes to spool. It can be recirculated so that there is almost no difference, but it is pretty hard to get the perfect angle going back into the exhaust and making the dump tube smooth all the way from the gate to where it enters the exhaust.

To me, the only reason to reciculate is if you don't want to deal with the noise when at boost or state laws. On some setups the exhaust or other things are louder than the wastegate though.

Sorry but I don't get that one. If the wastegate is working properly, shouldn't it be doing absolutely nothing until the turbo is fully spooled, and thus shouldn't there be no gasses coming through the dump tube interrupting the flow through the exhaust? I can understand more peak power, i just don't get how it alters spool. Thanks.

 

[Mr Peepers]

Don't quote me on this, but IIRC the rule of thumb is rerouting the wastegate back into the exhaust 18" after the turbine outlet to minimize turbulence. Many o2 housings for DSMs go against this. The main thing I would worry about is the entrance angle back into the exhaust, although like 1992awdlaser said, it's difficult to implement.

Just curious- how would it decrease the time to get to full boost when the wastegate generally doesn't open until a fraction before its reached?

Picking up 12-15 hp is COMPLETELY dependent on the setup.

It does mostly come down to preference. I like to floor it and not have everyone within a mile look in my direction. I also like to hear the turbo spooling and don't prefer the exhaust leak sound at part throttle.

EDIT: Wow, I'm really really late on this one; multi-tasking at its finest. I second that, kahl23.

 

[Black_Bullet]

Don't quote me on this, but IIRC the rule of thumb is rerouting the wastegate back into the exhaust 18" after the turbine outlet to minimize turbulence. Many o2 housings for DSMs go against this. The main thing I would worry about is the entrance angle back into the exhaust, although like 1992awdlaser said, it's difficult to implement.

Just curious- how would it decrease the time to get to full boost when the wastegate generally doesn't open until a fraction before its reached?

Picking up 12-15 hp is COMPLETELY dependent on the setup.

It does mostly come down to preference. I like to floor it and not have everyone within a mile look in my direction. I also like to hear the turbo spooling and don't prefer the exhaust leak sound at part throttle.

EDIT: Wow, I'm really really late on this one; multi-tasking at its finest. I second that, kahl23.

I agree, and I dont think it sounds all the good either.

My friend with a 2g gst just did a dump on his when he upgraded to a 3065 and it always sounds like it has an exhaust leak now. Has a raspier tone to it.

BUT, on my car I have open DP when my cutout is open and Im curious how o2 dump would sound WITH open DP... That would be something to hear .

If what y'all say is true about 10-15hp gains with dumping vs rerouteing due to turbulence, then maybe I wont get the rerouted punishment racing tubular o2 housing when i go external, and instead I could just get one with a dump and route it all the way to just right after the DP ( after my Electric cutout)
so that it will merge with the rest of the piping to not interfere with exhaust flow pre cutout.
Idk know though, that may be too much long unneccesary pipe under the car...?
As corny as it sounds, that may work.

To the OP, id just run it back to however you had it before the DP broke.
If you decied to dump it, I guess if your running enough boost and have a tight enough w.g. spring you wont hear it start opening up till you've built at least 15lbs or so which should keep it at least sounding normal for regular driving.

 

[Badgst96]

Hey guys I just want to throw something out there, well I have a 96 GST and I upgraded to a atmosphere dump o2 housing also and like BLACK BULLET said, it does sound like a HUGE exhaust leak. I have been told to fix it and get new exhaust he he and I tell ya, it does not sound too good. The atmosphere dump for a internal setup (especially for dsms) cant increase hp (I dyno tested) or help the turbo spool faster, all they do, to my experience, is help cure boost spike/creep by opening the wastegate freely at the psi desired with no interference. I would think the results differ for an external wastegate setup as the sound aswell but I have internal so who knows.

P.S: Get an empty coke bottle or any pop bottle and take the cap off (Plastic) and place your mouth over where the cap goes and make a grunt sound over it, I know it sounds dumb but thats kind of how it sounds like. Mine atleast ha ha