atmospheric dump o2 housing negative effects?

[jonezj]

I was just reading some stuff on garretts website and it mentioned that rerouting the exhaust gas that the wastegate bypasses back into the exhaust path usually improves turbo performance, but the fail to mention the reason. Me being uneducated just always thought that open atmosphere had to be good because it puts no restriction on the escaping gas. Hoping one of you turbo physics whizzes can help me understand why you wouldn't want to dump to atmosphere. Thanks
Julian

 

[brute]

It all really comes down to personal preference.

If you re-route, you better make it come in at a small enough angle as to create minimal turbulence.

If you dump, you better make a dump tube to get the exhaust to the atmosphere and not melt any wires or alternators.

If you dump it, you will probably get tired of the noise level. It becomes annoying after a while. But it depends what you want: a more sleeper-ish fast car or a dragster-esque street beast.

 

[DSM90AWD]

I was just reading some stuff on garretts website and it mentioned that rerouting the exhaust gas that the wastegate bypasses back into the exhaust path usually improves turbo performance, but the fail to mention the reason

You mean this:

External Wastegates are added to the exhaust plumbing on the exhaust manifold or header. The advantage of external Wastegates is that the bypassed flow can be reintroduced into the exhaust stream further downstream of the turbine. This tends to improve the turbine's performance. On racing applications, this Wastegated exhaust flow can be vented directly to atmosphere

All this means is that since you can plumb the wastegated exhaust back into the exhaust further downstream of the turbine with an external, the turbulence / backpressure would be minimized. Most internally wastegated turbos re-route within a few inches of the turbine (sometimes at very steep angles) which can cause efficiency losses.

For the best performance, dumping the wastegated exhaust to ATM will always be better, however is illegal in most/all 50states, and many do not care for the added noise it creates so trade-off the slight performance loss

 

[Slippi84]

Loss of hearing annoyed neighbors and lack of peace....all of which mean nothing to a true dsmer

 

[oldman]

Loss of hearing annoyed neighbors and lack of peace....all of which mean nothing to a true dsmer

Spoken like a true ricer.

 

[DSM90AWD]

Loss of hearing annoyed neighbors and lack of peace....all of which mean nothing to a true dsmer

An external with dump is really not much louder than a 3" exhaust (of which I hav both). An internal w/g dump onthe other hand sounds like a dump truck's exhaust brake

Then again I'm old and don't hear so good anymore

 

[Slippi84]

Spoken like a true ricer.

spoken like a OLD man


edit: IN all seriousness though if you have a car with a full 3" exhaust it will not be that much louder. And contrary to what oldman said I am far from a ricer.

 

[oldman]

spoken like a OLD man


edit: IN all seriousness though if you have a car with a full 3" exhaust it will not be that much louder. And contrary to what oldman said I am far from a ricer.

Don't be so sensitive , where's that GT14 500 AWHP dyno sheet at?

 

[pneumo]

An external with dump is really not much louder than a 3" exhaust (of which I have both). An internal w/g dump on the other hand sounds like a dump truck's exhaust brake

Then again I'm old and don't hear so good anymore

I have to agree with this. I have an external gate dumped to atmosphere and I couldn't tell much of a difference in the loudness from when I had an internal gate re-routed back into the exhaust.

 

[Slippi84]

Don't be so sensitive , where's that GT14 500 AWHP dyno sheet at?

with my car that goes 9:1 as soon as it hits boost

 

[nightspeed87]

quick dumb question, if you dump ; is it true or false that the longer the actual pipeing for the dump tube is the quieter?

 

[oldman]

with my car that goes 9:1 as soon as it hits boost

DSMlink no worky?

 

[Slippi84]

DSMlink no worky?

naw I think it's boost leaking after the MAF could be tb gasket or something dumb it will go sustain 85mph out of boost but as soon as you give it enough gas to get it boost it shits the bed.


No longer piping doesn't make it that much quieter it just makes it farther from your ear so it sounds like it is. Think about a car with no cat or muffler cause that's what the dump tube portion of the exhaust is.

 

[koho2731]

Well I can't say much for the length, but open WG to having a dump tube it made a huge differance in the noise level.

 

[bojanglesracing]

Now will dumping from the o2 help with boost creep?

 

[oldman]

Now will dumping from the o2 help with boost creep?

Internal O2 dump ALONE will only help with mild case of creep.

 

[bojanglesracing]

Ok so i am boosting 10 and creeping to 20 and/ i plan to turn it up to 20 would this help keep it under control?

 

[oldman]

If it only creeps to 20 and you have enough supporting mods to run 20, you probably don't need to do anything.

 

[bojanglesracing]

Well it goes a little above 20 never tried to find out how far. I guess i should put the boost up and see what happens.

 

[oldman]

Well it goes a little above 20 never tried to find out how far. I guess i should put the boost up and see what happens.

Why don't you do it right and port the turbine housing, unless you're looking for excuses to dump.

 

[bojanglesracing]

Just dont feel good about porting. I dont trust myself.

 

[oldman]

Just dont feel good about porting. I dont trust myself.

Nonsense, the only thing difficult about porting is getting started.

http://www.dsmtuners.com/forums/showthread.php?t=186525