worth porting a 10.5 housing?
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It was an E-bay o2 housing, not the highest quality piece, lol. The flange didn't quite match the gasket so i cleaned it up a bit. I also gasket matched the outlet. You want a smooth transition between the two pieces, by port matching the gasket to each piece you can do that. I centered the bolt holes and traced the gasket on both pieces. When i bolted it up i super glued the gasket to the turbo and bolted on the O2 housing. Centered the housing on the bolts and torqued it down, i could see in the o2 housing and they lined up perfectly.
,but i what i meant was that if the O2 has bigger inlet than the exhaust outlet then the transithion will be smooth,it's when it's smaller that makes things a little difficult.
...i've got a new 10.5 housing and before fitting thought i'd ask?In fact both units are twinscroll housings. Each version incorporates dual, side by side(divorced, siamese) turbine bypass ports. Externally they are distinguished by the fact that each has a different shape of flapper valve.
I think that yours is probably the newer single-flapper version, judging from the way that you've described it. At any rate, have you installed the housing yet or not? If you still haven't installed it, do you have it at hand?
Last edited by sparky; Apr 30, 2009 at 04:18 AM.
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Joined: Mar 2008
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From: uk
Have you installed the new housing yet? You probably already know that there are two versions of the 10.5 16G turbine housing, right? Here on EvoM, one is referred to as single flapper, while the older piece is called the double, or twin flapper version.
In fact both units are twinscroll housings. Each version incorporates dual, side by side(divorced, siamese) turbine bypass ports. Externally they are distinguished by the fact that each has a different shape of flapper valve.
I think that yours is probably the newer single-flapper version, judging from the way that you've described it. At any rate, have you installed the housing yet or not? If you still haven't installed it, do you have it at readily hand?
In fact both units are twinscroll housings. Each version incorporates dual, side by side(divorced, siamese) turbine bypass ports. Externally they are distinguished by the fact that each has a different shape of flapper valve.
I think that yours is probably the newer single-flapper version, judging from the way that you've described it. At any rate, have you installed the housing yet or not? If you still haven't installed it, do you have it at readily hand?
.
Last edited by leecavturbo; Apr 30, 2009 at 04:22 AM.
Post up a pic that shows the turbine inlet area if you have one. The turbine inlet area is located at the twin, side-by side inlet ports to the housing viewing inward from the flange that mates to the exhaust manifold.
I can give you a brief exlanation of how to easily port the initial part of the turbine inlet area to improve flow out through the turbine bypass port(s), since this seems to be of concern to you.
Now, you don't need to port the chamber that houses the WG flapper at all. So, leave it alone.
The other chamber, that is the turbine outlet side, you can do some porting on however. The aim here would be to lower exhaust backpressure, and thus improve the pressure differential between the turbine inlet and the turbine discharge.
Place the STOCK gasket on and align the four bolt holes. Then mark overhang around the chamber. Don't worry about the wall that divides the turbine discharge chamber from the WG chamber. So, you should have a cirmferential mark except for the segment of the divisory wall, right? You can scribe this line.
If you look at the turbine discharge chamber in your posted pic you will see a shinny machined cut inner circumference. That is where the turbine wheel's exducer spins. You do not want to grind that machined area whatsoever. So, you essentially grind from the outer edge of that machined area to the scribe mark.
Try to visualize that you will end up with the internal shape of a trumpet horn discharge. So it won't be a flat surface grind but will have a radius to it, like a trumpet.
This is how you grid the turbine discharge area of the turbie housing. This will reduce exhaust backpressure considerably, improving both spoolup and topendpower. Also it reduces EGT's.
The porting to improve WG flow is a separate operation and you needto post up a pic of the turbine inlet area to explainthat.
The other chamber, that is the turbine outlet side, you can do some porting on however. The aim here would be to lower exhaust backpressure, and thus improve the pressure differential between the turbine inlet and the turbine discharge.
Place the STOCK gasket on and align the four bolt holes. Then mark overhang around the chamber. Don't worry about the wall that divides the turbine discharge chamber from the WG chamber. So, you should have a cirmferential mark except for the segment of the divisory wall, right? You can scribe this line.
If you look at the turbine discharge chamber in your posted pic you will see a shinny machined cut inner circumference. That is where the turbine wheel's exducer spins. You do not want to grind that machined area whatsoever. So, you essentially grind from the outer edge of that machined area to the scribe mark.
Try to visualize that you will end up with the internal shape of a trumpet horn discharge. So it won't be a flat surface grind but will have a radius to it, like a trumpet.
This is how you grid the turbine discharge area of the turbie housing. This will reduce exhaust backpressure considerably, improving both spoolup and topendpower. Also it reduces EGT's.
The porting to improve WG flow is a separate operation and you needto post up a pic of the turbine inlet area to explainthat.
I'll explain to you how to port the initial radii of the bypass ports located in the turbine inlet area of your housing so that it will have more than enough bypass flow out through the stock WG puck.
I have run several configurations of the 16G, including a 9.8 cm TME, and a 9.0 cm EvoGreen with extreme levels of wastegate preloading and I've never experienced creep or spike with the stock ported passage and the stock diameter wastegate puck. But, if you want to spend your money on adapting a larger diameter puck, then go ahead.
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Joined: Mar 2008
Posts: 1,392
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From: uk
I have thought about doing this myself as Precision Turbo & Engine offers a larger diameter WG puck for the internally gated Garrett housings. But, I don't think that it will be needed in your case ad would be an extra expense.
I'll explain to you how to port the initial radii of the bypass ports located in the turbine inlet area of your housing so that it will have more than enough bypass flow out through the stock WG puck.
I have run several configurations of the 16G, including a 9.8 cm TME, and a 9.0 cm EvoGreen with extreme levels of wastegate preloading and I've never experienced creep or spike with the stock ported passage and the stock diameter wastegate puck. But, if you want to spend your money on adapting a larger diameter puck, then go ahead.
I'll explain to you how to port the initial radii of the bypass ports located in the turbine inlet area of your housing so that it will have more than enough bypass flow out through the stock WG puck.
I have run several configurations of the 16G, including a 9.8 cm TME, and a 9.0 cm EvoGreen with extreme levels of wastegate preloading and I've never experienced creep or spike with the stock ported passage and the stock diameter wastegate puck. But, if you want to spend your money on adapting a larger diameter puck, then go ahead.
