question about o2 housings

[cbellsondsm]

how come the 1g and 2g manifolds cant look like the evo 8 manifolds (the divider between the WG and EX outlet) be removed im guessing it will hurt flow?? any one know about this?

 

[David15151]

show me a pic so i know what you are talking about..

 

[Spln_Hrd]

i also am curiuse about what you are describing. but i might still have an answere.

to my knowledge the evo 8 16g is a newer version of the 16g, and it is a "twin scroll" turbocharger. the exhaust turbine has two differant angles and the exhaust is directed toward one in the low rpm for faster spoolup and then at both for higher boost levels. i am not 100% sure they use a twin scroll turbo but i did here that somewhere, and i know the turbo II rx-7's did

 

[blcknspo0ln]

it looks like similar to the t3/t4 outlets... ours is just one circle whereas the evo 8 has 2 seperate openings for the runners

 

[blcknspo0ln]

wait a minute.. the title says o2 housing, but your post is about the manifold...
just in case, i was referring to the mani

 

[David15151]

maybe he is talking about the divider between the wastegate and exhaust gas on the turbine housing outlet. ????

 

[Shadowfax]

maybe he is talking about the divider between the wastegate and exhaust gas on the turbine housing outlet. ????

if that's the case- you really don't want to remove it- it creates quite a lot of turbulence if you could- the TD04 O2 housings on the 3/S are all open- when JPDC created the TD04 dump tubes, it sucked trying to make the Divider wall - but the gains were great.

Consider it this way- if you just opened up all that area you would create a rather large opening yes, but then it necks back down to the piping size- any time you have small outlets opening into larger open areas then flowing toward a smaller pipe size you create turbulence - similar to gutting your main cat- sure it flows better- but you just put an open space 45% larger than your piping- the exhaust slows down, it cools, then it has to force back down to leave. Similar with the O2 housing. You don't want to do that.

Also, the divider makes O2 dumps wickedly easy.

 

[blcknspo0ln]

forgot who but there is a major dsm company [ RRE? SBR? ] that has a cut in the o2 divider ... just FIY..

but IMO the divider is a must also

 

[myblack98gst]

of course you can still cut the housing down to a thin wall between the 2 I left just enough on mine so the gasket would seal

 

[oldman]

I think your are talking about the part of the o2 that the wastgate merges back into the exhust. vfaq under porting describes enlarging the divider as much as you can, it will help with boost creep.

 

[blcknspo0ln]

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pic is borrowed from vfaq..

anyway in the pic you can see the divider [ so no confusion as to what i'm talking about ] .. i've seen t3/t4's and some 2g's have the wall cutout [or at least a hole made ].. so that both exhaust gases flow together. anyone have experience with this, not just hearsay?

 

[Syndicate13]

The ATR O2 Eliminator is made this way. Mine has absolutely no divider in the O2 housing. I wish I had a pic but I don't, and I'm not gonna take off my turbo to show you, sorry guys. I don't know if it is the most efficient way of doing things but it damn works. The ATR is one of the only exhausts that is a true 3" all the way and I have absolutely no boost creep whatsoever on my small 16g. My turbo is ported however with a 34mm flapper. I have heard from some wisemen on here that not having the wastegate gases and exhaust gases divided can cause some turbulence in the O2 housing leading to a little slower spoolup and a somewhat decreased max flow through it. It would be interesting to switch to a different downpipe and O2 housing and see if there is any difference in total airflow through the motor. Anyone local got a 2G AWD with exhaust that doesn't mind a few hours work?

 

[blcknspo0ln]

here's the pic i was talking about ... any comments?

 

[Shadowfax]

here's the pic i was talking about ... any comments?

yeah, see mine above

You're opening a resevoir to fill before air moves down, now our exhaust flows quickly, but it's still going to cause some turbulence. Some will ask- doesn't that same resevoir exsist even if it's divided... and my answer would be yes. It's a bit harder for air to flow back up the wastegate hole, but you can bet it does slightly. Once the wastegate opens, then yeah things change... but I still recommend a dump tube, well, at least for me