I have had interest in a 818 and really would love to see the Ecoboost in the car or at least an option to run one. I been keeping tabs on this and figured I would join to share my knowledge of the Ecoboost platform.

I have a Focus ST which is tuned and running full bolt-ons with the stock turbo. I use it daily, at AutoX, and Track Days. I have put over 40k hard miles on the car and it still funs smooth.

There are 2 motor options which could be a great fit to this platform.

2.0 Ecoboost
The stock turbo on this engine is small (Borg Warner K03) and hits peak boost (23psi) around 2700rpm and drops down to about 14psi at redline (6500rpm). The engine does not have forged internals and suffers from something called LSPI which all Direct-Injection engines can have. This means that while you want to feel that torque down low it causes the engine to be under serious stress which can cause cylinder temps to rise and the ringlands to melt. But if driven properly and prevent alot of low RPM high boost situations (typically staying above 3k in 5th and 6th gear) the engine can handle a hell of a beating.

My car puts down 287whp/370wtq on a blend of E30, for those who want to run E85 it just isn't possible with this engine unless you do aux fuel (add additional port injection) The high pressure fuel pump is just not able to flow enough fuel to keep the AFRs right.

Those who track the car haven't ran into any issues with Oil starvation with the Ecoboost 2.0 since Ford does put baffle/windage tray in the oil pan. We do run into issues with oil temps getting a bit high because of the tiny turbo being pushed really hard and dumping its heat back into the oil system. This can be resolved by a small oil cooler.

The Ecoboost 2.0 does have a kit to convert it to longitudinal.
kit here: https://performanceparts.ford.com/part/M-6006-20

2.3 Ecoboost
This engine is the same engine they use in the Ecoboost Mustang and the RS, if you look at dyno charts the curves are the same, just different power levels.

There have been known issues with this engine cracking and leaking coolant, it is actually a weaker block than the Ecoboost 2.0, with that said they make a 2.3 crank to use with the 2.0 block

Also some situation the 2.3 block has even cracked under stock power levels and tune. And with pushing the platform you even have cases of the 2.3 head lifting a bit from the block.


Intercoolers
The factory intercoolers for these engines are not great at all, the RS intercooler is better than all of them, but it is still barely acceptable. The intercooler heatsoaks very quickly and can take time to cool back down.

Engine Head
Both the 2.0 and 2.3 heads are what we refer to as Headifold, the exhaust manifold is built into the head and there is only one big exhaust port. The 2.0 is designed for the use with a single scroll turbo, and the 2.3 is designed for use with a twin-scroll.

There is an aftermarket head available for the 2.0 which goes back to being a traditional head with the need for a exhaust manifold/header.

Transmission
The Tranmissions used in the Focus ST is actually a Getrag 6MTT450 which is a very strong and small unit. It is a 3 shaft design and 5th,6th,R have a different final drive ratio than 1st through 4th.

There is a proper LSD available for this transmission from OSGiken, Quaife, and mFactory.

The transmission is holding up just fine to STs that are running 400+whp without any issue. And the axles can handle the stress of launching the Focus ST on slicks without any concern, they are overly built.

The way the 2.0 Ecoboost and Transmission sits in the Focus ST allows for it to sit pretty low. Since the transmission is self contained to the driver side, the engine takes up the passenger side of the engine bay. From the bottom you have full access to the oilpan and the transmission is not in the way.