LocostUSA.com

I am rather certain this engine can be paired directly to the Miata 1.8L transmission and drivetrain, readily available, or thus can be an upgrade to an existing 1.8L Miata based car.

I too think the 2.0 L Ford Ecoboost would be an excellent choice for the Locost or kit build and should be seriously considered. The engine as used in the 2012 and newer Focus ST is rated at 252 HP and 270 Ft lb. would be a good candidate for our cars.
I have checked my local salvage yards and it is not difficult to purchase complete engine with turbo under 60 K miles for $1,500. To me this makes it a very economical option for the kit. To this price you would also need to purchase and transplant the Focus ECU( always easier typed than done) or possible use aftermarket for off road use. Also you will need the fly by wire throttle pedal and harness. I am rather certain this engine can be paired directly to the Miata 1.8L transmission and drivetrain, readily available, or thus can be an upgrade to an existing 1.8L Miata based car. One issue that will need to be worked out is these engines use a pedal fly by wire system. The throttle and pedal box will need to be designed or modified to accept Ford throttle pedal. Ford racing does sell such a pedal or you can probably adapt the Ford Focus pedal. The Ford pedal is a pendulum style pedal. This torque level is at the maximum what most of the Miata Turbo group owners say the Miata Trans can handle. Another option would be to mate this engine up to a Tremec T5 using a special cast adapter. Also the Tremec is a readily available , inexpensive and light weight and very strong option, actually not much more than the Miata box. I actually have had MNR mock this combo up, 2.0 L ecoboost and Tremec T5 for fitment and jig and do offer this as an available option for purchase for the VortX. FYI I did check the 2.3L and as I recall the 2.0L and 2.3 share the same block and bolt pattern. So all above comments should be similar for the 2.3 but mostly likely more torque than the Miata box could handle for long life. T5 would be better option.
But I have not any personal experience with the 2.3L ecoboost.

Tom
fastcraft.biz

Also would this same combo NC Miata box should mate to the 2.0 liter Duratec type L also?

Ford racing also sells a north-south kit for the focus st engine... it actually just looks like a lot of the parts from the mustang ecoboost: https://performanceparts.ford.com/part/M-6006-20

You know geek, that's a very good question. I always thought the 2.3 was just a stroked 2.0 but they may have gone with a different block pattern at the flywheel end. in which case you couldn't use the Getrag 6 speed out of the Ecoboost Mustang.

Tom

And at 299.00, that's cheap!

Tom

That's that, then you can buy a NC miata oilpan, while you are at it get the counter-balance shaft delete kit.
http://www.full-race.com/store/ecoboost ... lug-1.html