Ken, first at all congrats to the choice of your Mog. I can imagine that the P4 is the best allrounder out there and you may enjoy so different ways to drive her, sporty or cruising.
Regarding the 4/4 engine objective, if a modern little ecoboost seems to be a good choice, and even if it may result in a really good package I guess it will be of a different character. That does not mean to become „worse“ but I personally would miss the (most times legal) racing feel. The standard Sigma, even if altered with a manifold and an ECU remap keeps the special combination of sufficient low rev torque together with the in my case emotionally important rev willingness concerning this very car.
On the other hand, as Gambalunga mentioned, a highly tuned Sigma will also alter the car to become a completely different animal. At the end she would behave like the 2015 Williams race car. Such a modification I could not need for my way of sporty road use.
TBH the 4/4 ECU remap in combination with the sports manifold is enough power tuning in my case. The first acceleration tests were just nice but did not show the real differences, Now after some weeks of usage familiar roads demand much more brake action, and the tiny tires are more often at the limit. I‘m happy as she is now concerning her (and my) limits.
More power would demand wider tyres, different suspension and more so on... Any further tuning which I can see will only address a slightly quicker throttle response without sacrifying her low torque abilities which is the reason why I‘m wondering about the progress of the Williams intake solution.
Andymot did you really mean 250HP instead of 150HP or was it a typo?
Regarding the Morgan fleet, what I can imagine to become a successful offering could be a Roadster combined with the Mustang 2.3 ecoboost engine, perhaps a little bit reduced concerning the very high power figures as is now.
It could be a different but plausible addition to the current 4/4 and the Plus 4 more addressed to be the effortless and sovereign cruiser in first place.
