They can handle 400+ to the wheels for short term bursts on pure factory stock internals, to handle the cylinder pressures necessary to
maintain that kind of power, steadily, for
long periods of time is another story which no one it seems has really tested.
I'd like to see an endurance test on an engine dyno of a 1.6 Ecoboost fitted with ALL of the necessary auxiliary add-ons/mods and very powerful fans in front of the full race size IC to even attain those power levels, and run at those power levels until it pops.
I wonder how long it would last.
From reading on here, the deduction I come to is that ancillary fueling (as in water-methanol injection, or an added single fuel/ethanol mix injector) is not absolutely necessary until one hits ~330 WHP, although it does seem to take
at least a 70% 93 octane fuel/30% ethanol mix to hit that 330+ to the wheels mark.
(
PLEASE someone, correct me if I have the above, or ANY of this post, ALL wrong!!)
As far as I have seen, or heard, no one has come up with much bigger direct injectors and stronger/higher capacity D.I. fuel pumps, or with a doubled up direct injection system (2 per cylinder) yet, probably due to the logistics involved, programming the ECU for it, actual room available in the head's combustion chamber roof, and of course, the prohibitive cost involved in this endeavor.
I do believe I have seen, or at least heard of someone adding a whole ancillary PORT injection system (1 port injector per cylinder) in addition to the factory D.I. system, to help with big power/turbo fueling needs.