Questions on EVOIII 16g, EVO O2, and EVO III manifold

[Zmann42087]

I've been doing a lot of reading on here and it has spawned some questions. I know the EVO O2 housing flows better than any DSM O2 housing (1g or 2g). However, is it necessary to port an EVO O2 housing to eliminate boost creep on an EVOIII 16g? Yes, I know to eliminate boost creep on an EVOIII 16g you need to port the wastegate flapper area and the stock O2 housing to decrease the "turn" into the wastegate entrance. I'm just wondering if the latter part is needed even with an EVO O2 housing. If porting is still necessary wouldn't it be better just to pocket the $100 for an EVO O2 and port the hell out of my 2g O2?

Also I have questions regarding the EVOIII exhaust manifold. I understand the EVO manifold has a larger collector that matches the 7cm exhaust housing on a 16g. Is it worth the $150? If didn't get the EVO manifold, should I port my 2g manifold to match the 16g's 7cm hot side?

 

[kmoore]

Save yourself some money and just port out your 2g items (O2 and manifold). How much you port CORRECTLY desides how free-flowing its going to be.

 

[romeen]

With regard to porting the wastegate passage of an EVOIII O2 housing I would recommend doing it although I can't say whether or not it is "necessary." It will not harm performance and may save you having to pull the turbo/housing later if you do get boost creep. I ported mine but I have a 2.5" exhaust which is much less likely to lead to boost creep so I can't say with certainty that the porting alone is responsible for my consistent boost control. You will have to do ALOT of porting to get a 2G housing to have the same flow as an EVOIII housing.

The 2G exhaust manifold, on the other hand, is nearly identical except for the size of the collector diameter (60mm vs. 54mm). If you want to save money then port your 2G manifold. But be warned, the cast iron used in the manifolds seems to be much harder than that used in the turbine and O2 housing. Even with a carbide grinding bit it takes some work to enlarge the collector size.

When I switched from stock 2G manifold and O2 housing to EVOIII pieces (with nothing else changed) I noticed a significant improvement in turbo response and a little bit of improvement in high end pull.