ElementSix

I cant get my hands on either housings for right now so I would like to see the differences between the two. I have searched the web for aftermarket o2 housings and notice some have divided gaskets and others dont. Why is this? Is the Evo 9 turbine outlet divided from the iwg outlet? If so, can anybody provide me with some pictures? I originally assumed Evo 8 o2 housings are compatible with Evo 9 housing and vice versa. If not there must be some sort of protrusion from either the o2 housing or the Evo 9 turbine housing.

HELP!

TouringBubble

iTrader: (2)

You can use either style gasket on either turbo. The stock gasket is not divided ... It likely has something to do with flow characteristics and pressure differentials.

ElementSix

Both the Evo 8 and Evo MR turbochargers i have used have had undivided gaskets in between the o2 housing and turbine housings.

TouringBubble

iTrader: (2)

Sorry ... that was a typo ... the stock gasket is NOT divided. You are correct.

sparky

iTrader: (1)

I am not sure that I completely understand your question. However, AFAIK, the VIII and IX turbos have interchangeable turbine housings.

EDIT: Some aftermarket gaskets, such as the shiny ones that come with EBay O2 housings do have a center strip which coincides with the divisory wall between the two chambers of the turbine housing. But you don't want to use those cheap aftermarket gaskets anyway. Just go with the Mitsubishi gasket.

Honto

iTrader: (34)

Manifold to Turbo gasket is divided, Turbo to o2 housing gasket is not, even tho they are kept separate until at the end of the o2 housing. I use a divided gasket from turbo to 02housing or my 02 DUMP would leak at idle. If i had to guess why mitsu didn't use a divided gasket it would be that the space is so thin that it might blow out the gasket material and compromise the rest. Any 02 housing will work with any year 03-06, i would suggest an ebay one.

TouringBubble

iTrader: (2)

You are correct if you are referring to gaskets. There is an actual division of the chambers where the turbo bolts to the O2 housing, but the gasket doesn't seal the center "wall" at this location. On the manifold connection the gasket does completely seal both chambers.

ElementSix

LOL all these replies about gaskets and im actually talking about the o2 housing and turbine housing . sorry about the confusion but i was referencing the gasket as an example (easy image to find).


*What i want to know is if that "divisory wall" is found on both the EVO 8 and EVO 9 turbine housings.

*I know the EVO 8 turbine/o2 gasket is not divided, is this the same for the EVO 9 turbine/o2 gasket?

If so, i can see how the EVO 9 turbo would make more power and spool sooner.

sparky

iTrader: (1)

AFAIK, all years of Evo 16G turbine housings use the divorced, twin chamber design. This includes the dual-flapper 10.5 hsg., the single-flapper 10.5 hsg., the 9.8 hsg., as well as the 9.0 hsg.

I am not sure, although someone like Trinydex probably knows, but I think that all IX 16G turbos came with the 10.5 single-flapper housing. However, I think that this same identical 10.5 single-flapper came on the '05 and maybe the '04 USDM Evo VIII's.

At any rate, the only significant difference between the VIII 16G turbo and the IX 16G turbo is the compressor housing. Turbine housings can be freely swapped between the VIII & IX turbos. because they are identical.

The horsepower increase on the IX turbo is due to the redesigned compressor housing, and has nothing to do with the hotsides. I personally have had a 9.0 dual-flapper(which only came on auto cars), a 10.5 single-flapper, as well as a 9.8 housing side-by-side on the work bench and they all feature the divorced, twin chamber design. Hope this helps!

ElementSix

It does! Now my next question: Why is the EVO 8 turbine/o2 housing gasket not divided?

TouringBubble

iTrader: (2)

See my first post ...

ElementSix

ok, Does the EVO 9 gasket seal the cavities from themselves? If so wouldnt this contribute to higher power output?

sparky

iTrader: (1)

The VIII & IX gaskets are the same AFAIK.

sparky

iTrader: (1)

On Buick Turbo Regals(GN's), the most popular DP for Garrett TO4E's was the Terry Houston 3" DP. The TH DP was a one-piece design that eliminated the factory post-turbo cast elbow, which was kind of equivalent to our O2 housings.

In the Terry Houston DP, the wastegate and exducer flows both merged immediately after the turbine housing. In other words, there were not two separate chambers as in most O2 housings available for the 16G turbos.

I think that the idea of maintaining separate, or divorced chamber flows for the gases exiting the wastegate bypass port and those emerging from the turbine housing's exducer outlet is overrated. At least that's my personal take.

At any rate, if you think about it, on the O2 hsgs. available for the Mitsu 16G's the two chambers combine just an inch or two further downstream still within the confines of the O2 housing. There is a merge port that combines the two chambers just a inch downstream from that non-divided gasket which you are fretting about. (I don't think that you should be losing anymore sleep over this one.)

Sorry for the OT about Buicks. I am just showing the effects of old age.