O2 dump ?

[GearheadJ]

OK... I've got a Big 16g a/r .70 with a FMIC and some ok piping.. has a recirculated 1g BOV and a O2 dump.. still seems to have a wicked creep on boost.. I've turned my manual boost controller down and it still hit's 15lbs and creeps into 17lbs.. hitting fuel cut at times in between creep too...

Now, I'm considering eliminating the O2 dump and recirculating through it & letting the BOV do it's JOB.
Clearly, I need a lot more fuel supporting the system & a few other odds & ends..

I just got the car a few weeks ago, and trying to learn what all is there and what isn't..
because clearly the kid that I got it from didn't build it & was a bad liar..

Anyways... are there any benefits to the O2 dump ? or is it just an annoying noise maker than never goes PShhhh-Psh-Pshhh-PSh-Psh...

I want to plan for a street-able 450+ AWHP.

 

[1990AWD]

OK... I've got a Big 16g a/r .70 with a FMIC and some ok piping.. has a recirculated 1g BOV and a O2 dump.. still seems to have a wicked creep on boost.. I've turned my manual boost controller down and it still hit's 15lbs and creeps into 17lbs.. hitting fuel cut at times in between creep too...

Now, I'm considering eliminating the O2 dump and recirculating through it & letting the BOV do it's JOB.

The BOV has nothing to do with the wastegate, and the BOV doesn't care if you're dumping or recirculating the exhaust.

If you're still creeping with an O2 dump then I would recommend porting the turbine housing and giving that a try.

Anyways... are there any benefits to the O2 dump ? or is it just an annoying noise maker

The wastegate dump just gives a much more free exit through the wastegate for the exhaust, reducing boost creep. And it shouldn't be that annoying, the wastegate only opens at full boost so it's not like it's constantly loud.

 

[pokemon]

port out the wastegate hole; that should help you out for sure

 

[Archer Fabrications]

A 16g .70 ar????????? Holy crap thats my hx40's compressor size. Are you sure you are typing that right???

 

[1990AWD]

A 16g .70 ar????????? Holy crap thats my hx40's compressor size. Are you sure you are typing that right???

haha I didn't even notice that, eBay turbo maybe? :idunno:

 

[SleepyGST]

Like 1990AWD said, O2 dump has nothing to do with recirculating the blow off valve. I think you might be confused and mixing up terms...

O2 Dump is when your O2 housing doesn't recirculate wastegate gases back into the exhaust, it just dumps it into the atmosphere.

I think your confusion is in the term "dumping to atmosphere" or "atmospheric dump." you can atmospheric dump (vent) your BOV and you can atmospheric dump your O2 housing. You can recirculate or dump/vent both the BOV and/or O2 housing.

 

[LandSpeed-DSM]

Seriously you guys? .70A/R only refers to the ratio of difference in diameter from inducer vs exducer.

An HX40 Pro compressor is a 49 trim, my standard HX52 is only a 47 trim.

14b is a 55 trim compressor, small 16g is a 60 trim, but a big 16g is a "mere" 50 trim and an 18g is also a 55 trim.. see where I'm going with this? It's a term meaningless out of context.

 

[GearheadJ]

haha I didn't even notice that, eBay turbo maybe? :idunno:

No..Not Ebay.. Hybrid built..stay with me here..keep reading..

A 16g .70 ar????????? Holy crap thats my hx40's compressor size. Are you sure you are typing that right???

Yes, It's right.. and just like above..stay with me and keep reading...

Seriously you guys? .70A/R only refers to the ratio of difference in diameter from inducer vs exducer.

An HX40 Pro compressor is a 49 trim, my standard HX52 is only a 47 trim.

14b is a 55 trim compressor, small 16g is a 60 trim, but a big 16g is a "mere" 50 trim and an 18g is also a 55 trim.. see where I'm going with this? It's a term meaningless out of context.

^^ BINGO ! We've got a winner ! Someone who understands turbo sizes.
I have a hybrid BIG 16g with a larger hotside than most. it's already been ported and spools amazingly.

Yes, I'm retarded and confused my wastegate and bov terms

 

[LandSpeed-DSM]

I managed to mess up my wording on that somewhat..

A/R is useful for comparing critical area and radius size inside the same family of turbo, like trim size. So the point stands but it's different from trim.

As mentioned earlier port out the wastegate hole and the ledge proceeding it in the volute entry. This will not only help with redirecting flow to this path of least resistance to atmosphere but should allow for greater flow capacity. The increase in exposed surface area on the valve should open it easier as well.

Now how do you know the a/r on an MHI turbo? They tend to only list the nozzle area in cm2 and only for the turbine.

Is there a custom turbine or compressor housing on it? Pics?

 

[GearheadJ]

Yes. I do have a custom housing set up.. I will try to post a picture of the hot side for you guys to see.

 

[JusMX141]

OK... I've got a Big 16g a/r .70 with a FMIC and some ok piping..

Sounds like someone went crazy on eBay with about $300 to spend.

Now, I'm considering eliminating the O2 dump and recirculating through it & letting the BOV do it's JOB.

One mounts to the exhaust, one mounts to the charge piping. That's like putting more air in your tires because your car is burning too much oil.

I just got the car a few weeks ago, and trying to learn what all is there and what isn't..
because clearly the kid that I got it from didn't build it & was a bad liar.

Let's keep this statement in mind as we progress through this multi-quote, shall we?

Anyways... are there any benefits to the O2 dump ? or is it just an annoying noise maker than never goes PShhhh-Psh-Pshhh-PSh-Psh...

Assuming you actually mean an o2 dump which attaches to the o2 housing on the exhaust system, this is not the first time such a topic has been discussed on this site.


http://www.dsmtuners.com/forums/newbie-forum/361190-hotside-dump-tube-how-much-power.html

http://www.dsmtuners.com/forums/newbie-forum/350978-02-dump.html

http://www.dsmtuners.com/forums/newbie-forum/349236-o2-dump.html

http://www.dsmtuners.com/forums/newbie-forum/345308-o2-dump.html

http://www.dsmtuners.com/forums/newbie-forum/317530-02-dump-pipe.html

http://www.dsmtuners.com/forums/bolt-tech/182232-dump-not-dump.html

I want to plan for a street-able 450+ AWHP.

Better plan to lose those aforementioned eBay parts and go with a much larger turbo than what you have.

Someone who understands turbo sizes.

That would be me.

I have a hybrid BIG 16g with a larger hotside than most. it's already been ported and spools amazingly.

No, you have an eBay special 16G. The ".70 a/r" is a dead giveaway. I know this because factory housings are 7cm2 or around .49 a/r...but seeing as Mitsubishi makes their turbos in Japan, a metric a/r measuring system is used- hence the "cm2" (metric) versus "a/r" (domestic).

When the Chinese made their shitty imitation of a fine Japanese product being the Evo III 16G, they translated the "070" from the MHI housing (meaning 7cm) into ".70 a/r", which is false.

Going back to the statement in bold above...you expect a guy who you got the car from which apparently didn't build the car for you and was also a "bad liar" to tell you the truth about the turbo you have?

Yes, I'm retarded and confused my wastegate and bov terms

...add "turbocharger" to that group as well.

 

[c2ypt1c]

No, you have an eBay special 16G. The ".70 a/r" is a dead giveaway. I know this because factory housings are 7cm2 or around .49 a/r...but seeing as Mitsubishi makes their turbos in Japan, a metric a/r measuring system is used- hence the "cm2" (metric) versus "a/r" (domestic).

When the Chinese made their shitty imitation of a fine Japanese product being the Evo III 16G, they translated the "070" from the MHI housing (meaning 7cm) into ".70 a/r", which is false.

^^ BINGO ! We've got a winner ! Someone who understands turbo sizes.

I'm going to tell my kids this story at bedtime. Once upon a time, the chinese, in an effort to lower the cost of a 16g turbo...

Anyway, for the cost of an o2 dump, you might as well get an evo o2 housing:
EXTREME PSI EVO III O2 Housing

wish I had seen that before I bought a dumped o2...

 

[JusMX141]

I'm going to tell my kids this story at bedtime. Once upon a time, the chinese, in an effort to lower the cost of a 16g turbo...

So true.

What they're doing is no worse than going to a dealer to look for a new Diesel truck....but when you lift the hood you find a base model V6 underneath despite the Diesel badges all over the truck. Horribly misleading....but what the f*ck do they care.