I would be less optimistic of the correction factor at 10-12% it's going to be around 300hp. It drives well but as the torque drops away due to the turbo you can really feel that it's at the turbos limits.

If you've already got the gtx I'd be tempted to say fit it now as even mapped to around 300hp it will be far more efficient and easier on the engine than the standard turbo. The advantage to the gtx is that if you mock everything up around the standard turbo so long as you have the physical space for the bigger turbo all the boost piping and down pipe will join straight up as opposed to the efr where everything needs to be made to fit. (What flange is on the gtx as that would be a determining factor in which flange you where going to buy).

The issue with the bottom end is that everyone has pushed it on standard injectors with the standard ecu and from the few who have done it in the uk and the many who have done it in the US (focusst.org is an invaluable resource I have found) the ring lands crack and fail due to leaning out. Realistically so long as you can supply the fuel and you map sensibly the bottom end should be good up to around 400hp at the wheels which would equate to around 440hp at the crank although that is pure speculation that I hope to validate at some point this year.

In order to supply enough fuel there are currently two options for di injectors. Mountune which have been proven up to 400hp at the crank although which depending where you look seem to be rated at 1250cc and give you 10% headroom over stock or the deatschwerks injectors that have just been made available that are rated at 1750cc ( although I have no idea how the compares to conventional injector ratings) and claim 30% headroom which should get to that 400whp target optimistically. As far as the hpfp is concerned from the limited info I've seen available it is already a higher end Bosch unit. Where the VAG engines where running 1700psi rail pressure and the internals had to be upgraded to get to 2200psi+ I'm led to believe that the ecoboost is already running around 2200psi rail pressure with some headroom available in the ecu ( I would check that with Simon though as I cannot remember what actual figures will ended up with and those numbers are just from what I had read in my research). I know on the lpfp side I'm running an st180 system at 100% duty cycle through a regulator to supply 4 bar and it's got no issues supplying my current tune and I have no plans to upgrade it with the big turbo as it should be fine.

One thing that is continually recommended by the us tuners is a totally upgraded PCV CCV system. There is the PERMPLATE or SpeedPerformance do there own design of the same thing. If you search focusst.org for info they will have piping diagrams and everything but it certainly seems the way to go.

My aim to prove the research above is going to be deatschwerks injectors, mountune or peron turbo elbow, efr6758, new down pipe and boost piping, mountune sump baffle and an upgraded PCV system. If some one disproves me before then I'll forge the engine first and whilst its out I'll probably fit some piper cams as well. But let's see how the money goes first.

One final note I wouldn't expect the torque to be any higher than what it's already pulled and I'm still on the standard clutch with absolutely no issue so in the even lighter Elise I don't think you would need the expense of an updated clutch unless it is needed for other reasons.

Happy to offer what details I've gleaned from many hours of reading so feel free to ask.

Cheers

/Tim

*edit* I did see an injector table for the deatschwerks injectors that suggested the hpfp from 2.3 in the mustang is capable of 3500psi rail pressure where as the plots for the 2.0 stopped much earlier so if the hpfp did ever become an issue that could be a viable upgrade assuming you could get hold of one. I will try and find the plot now.

*edit 2*

http://www.deatschwerks.com/images/s...0Summaries.pdf

That's a plot showing the deatschwerks injectors on the various ecoboost engines and the below is the flow comparison on a 2.0.