GT vs GTS

Okay so I really like this thread and know it's old. However I fell like its incomplete. This thread doesnt talk about the MVIM System that is on the GTS and not the GT and think I need and this post needs more clarification on that. I've read up on the MVIM. I built a gen 3 GT as my daily but wanna turn it into a circuit car I'm debating on getting another GT and rebuilding my daily as my current one has no moonroof and I just want one (if I'm gonna do all out on my daily I want what I want) so my one without the roof will get the roll cage and be the racer. I know i could go with a gen 2 and get more power to weight ratio. I just love the gen 3's always have however when building a race car you are still shooting for maximum performance. Hence why I ask about the MVIM. So from what I understand the MVIM is a system built into only the GTS. It has to do with the more aggressive cams on the GTS allowing for a difference in fuel economy as well as power based on how you drive the car. You stomp on it you get the high lobes and terrible fuel economy for more power, drive it economically you get the low lobes and better economy. So I'm curious this system seems like its more for the fuel economy yeah? I mean you could just run more aggressive cams on the GT, with 10:1 pistons, without the GTS ECU component, and end up with the same power but wouldn't get the fuel economy? Right? I want to stick with a GT tbh, the parts are easier to find and GTS piston rings alone are a pain. So I'm trying to build a GT that doesn't need to argue about the GTS. I want the 10:1 and the more aggressive cam set up. (I don't want the gear ratio change in the transmission) So if I do that essentially build a GTS engine without MVIM and when we are talking about just power. Does the MVIM really matter if I have all the rest? Or is there more benefits to the MVIM I'm not understanding?

When parts shopping this question really came up due to the fact the pistons are different with or without MVIM. So has me really curious as to why the pistons need to be different for this.

P.S. Been on this forum for years you guys usually provide my answers without needing to write anything. This is the first reply/post I'm adding so If i missed a post that covers it feel free to link it. Thanks.

As far as the engine goes I would assume you can just not hook up the little butterflies in the intake manifold. Now without that being hooked up will at least throw a check engine code, what I don’t know is if it will not allow the engine to run? Automatic may have an issue here too since it communicate with your engine when selecting gears. But it may work as well that idk. Tbh idk for sure if that will work from my extensive conversation with @Silvertune I learned really the only difference in the GT and GTS engine that will matter for you is those butterflies and if that not being hooked up will cause the ECU to not run the car? Otherwise assuming is manual there should be no issue transmission and ecu wise. If automatic there is more questions to be raised since the ECU does all your shifting and needs to know what the engine is doing in order to do that. It might not matter with the engine being swapped but I know you can’t just swap an auto transmission between the GT and GTS. Question is will swapping the engine matter for that at all? If it’s auto. If it’s manual then you should only have to worry about the butterflies in the intake manifold and how that will effect the ECU.

Silvertune will know though and started this thread so I’m sure you’ll have a definitive answer soon!