A Smaller EFR
 

2.0L Ecoboost stock turbo (Focus ST), it looks like an EFR, it drives like an EFR, its made by BorgWarner, Ford Racing claims its a ceramic ball bearing turbo with a low inertia turbine. It has the EBCS and the BPV built onto the compressor cover. And unlike a lot of OEM turbo's these days its not cast into the exhaust manifold. Another upside, its only $1300 from the dealer new. But the housings are goofy shaped, as in, if you put it on a side mount manifold it might be sticking out of the hood, or on a top mount the waste gate flange is angled upwards, and on a bottom mount manifold it would be inside the frame rail unless you stuck the flange very close to the block.

Pictures taken from full race
https://www.miataturbo.net/attachmen...ine=1405108878

https://www.miataturbo.net/attachmen...ine=1405108878

Geoff says its a K03 but its got to be a new model K03, redesigned with the EFR tech.

No Ti-Al turbine wheel = no magical EFR spool

As far as I understand, Ti-Al turbine wheels are ~5 years out from being applied to an OEM application.

More searching to be done. I guess they could be "low inertia" the same way that the Kamak SLS turbines and Garrett GTX are, but having less fins but better aerodynamics to make up for it.

We've got a '14 Focus ST in the garage. It's the wife's DD. Factory boost of 20psi is quite fun and quick spooling, but still under 300hp. My 6258 arrived today and was under $1500 with the v-band flange and clamp. At $1300 for the ST turbo, its not a big enough difference to consider IMO.

Yup, these seem to top out at 280hp. Its perfect for someone who doesnt want 6258 power but wants something with less lag than a 2560R.

...so perfect for a stock BP?

If you are only making 280, why bother with the hassle of this funky turbine arrangement. Just so it spools a couple hundred rpm better? I think you'll find part of the spool time reduction in the direct injection as well.

For the record I love my FoST. Spools fast and loads of fun. I just don't think this is the droid you are looking for. If it was $600 maybe.

Are the ST guys commonly swapping turbos? Seems to be an easy cheap pickup on ST forums, a quick cut, and a V-band flange welded on.

There are a few GTX and EFR turbo setups and no clue what the used ones go for. Most keep it to swap back to for dealer issues. There are some going 300+ on stock turbos I thought.