Turbo upgrade reccomendations

I will be replacing my k04 turbo on my 2010 MS3 with 140k miles on it because of oil consumption and signs of white smoke at idle. I'm declaring it to be blown seals. I will be using this opportunity to upgrade to a bigger turbo as well as all the supporting mods for safe performance on the stock block. I want more power somewhere around 300- 350 whp and have a setup that can eventually be built up to 400. I already have a k&n performance air intake installed.

Here is what I'm thinking as my essential mod list:
- Corksport ST4 turbo or BNR S3
- Autotech HPFP
- 3" downpipe
- accessport tune
- oil catch can
- new pcv valve

Additional mods:
- front mount intercooler
- 3" catless pipes

Should I go with the CST4 or BNR S3? With that, what other mods are important to install?

I will be upgrading everything at the same time with the tune so I would like to get a complete list that will get me the performance I want.

 

FWIW if you're looking for a turbo that can give you some power and get you to the 300 hp range I have a BNR S1 for sale. Of course a S4 or CST4 would put you over that but if you need something now to fix oil consumption or smoke that would be a cheap replacement that's a step over stock.

 

You can add rear and side motor mounts to that list...my 2c

 

I literally just went through this. Like almost to a T.
First diagnosed the smoke:
https://mazdaspeeds.org/index.php?threads/did-my-turbo-just-puke.10653/
Then asked pretty much the same question you just asked:
https://mazdaspeeds.org/index.php?threads/should-i-replace-or-rebuild-my-turbo.10674/
Then bought an S3 and have been driving it.
https://mazdaspeeds.org/index.php?threads/rang-a-stangs-genwon.10739/

 

You needing any of those parts ?
I’ve got a 3” downpipe welded to catless 3” all the way back
Corksport oil catch


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