Porting 2G O2 to Evo III 16G

[High PSI]

I'm installing a JusMX billet bastard 20g in place of the old and trusty ported 14B that I've had on the car for the past ~16 years/20,000 miles. The housings is off a knockoff Chinese 16G that had everything thrown away except the compressor cover (which has been machined), turbine housing, and actuator. It has a completely-new CHRA and the upgraded thrust parts have been installed along with a KTS D620C billet 6-blade 20G compressor and a Kamak/Kinugawa 9-blade TD05H turbine.

I have a 2g O2 sensor housing that I previously port-matched to the Mitsu turbo-to-O2 Housing gasket, and as such it exactly matches the new O2 gasket that I have. When I lay this gasket over the turbo, the hot-side-outlet is slightly larger than the gasket around the entire outer diameter, but particularly at the web between the wastegate and the hot-side-outlet.

I thought that I possibly was using the wrong gasket (T25/14B as opposed to Evo3), but have since been informed that Mitsu uses the same gasket for all three?

Of course, at the the wastegate section of the turbo there is a lot of material there that I ported out on the 2G O2 sensor (and my prior turbo) to match the gasket.

I am considering port-matching the hot-side-outlet of the gasket to the turbo, then further port-matching my O2 sensor housing to this ported gasket (very little porting required here). On the wastegate opening, I am uncertain as to whether I should hog out the turbo to match the gasket and O2 housing, or leave it as is and just let the air-path open up at the O2 housing? I'm leaning towards leaving it as-is - not worried about creep with my current setup (2.3L, built head, supporting mods) and concerned that porting out the wastegate side would leave too thin of a web between the two outlet sides.

 

[rabenne]

Have you ever heard they saying "a picture is worth a thousand words"?

I think a few pics here would be instrumental in getting help... I want to understand, but that's a lot of confusing description! (and my reading comprehension sucks)

 

[ErikTande]

Yeah, post a few pics of the turbo and housing : )

 

[High PSI]

Sorry...took all these before; forgot to attach!

As noted the O2 housing gasket is smaller than the turbo hot-side outlet, so obviously can't see the difference with the gasket layed over the turbo. It's a very small difference (~1/16" lip around the entire outside, though as noted thicker at the flange).

 

[EC17PSE]

The evo 3 gasket is different then a dsm gasket, the dsm has a smaller turbine but huge wastegate hole but the evo is huge turbine but smaller wastegate hole.

Either not worry about it and bore what you can.