Tweakable engines

[Tweeker]

I suggested this awhile back, but tweakables have been added since then, so this might make a little more sense now.

I think that it would add a lot of variety if you could customize engine by adding or removing features from them, such as generators or gimbals. Also possibly tuning the isp to a usage range, Surface, middle stage, or vacuum. Maybe even have an XL (+25%) or a mini (-25%) version of the engine

This would allow a greater variety without adding parts.

[Tery215]

The only difference between the -30 version and the -45 version (what am i talking about?) is the gimbal.

It'll be confusing to be able to make a -30 version that's the same as the -45 version.

[OrbitusII]

I think that this could be quite useful if done right. IRL, SpaceX has two variants of the basic Merlin engine in use: atmospheric (Stage 1) and vacuum (Stage 2). Their performances are naturally going to be different, but they are based off of the same Merlin engine series. I can see how this could be done now using the same modules as the RAPIER, but that allows modes to be switched in flight. I'd like to see it work similarly to the Firespitter mesh switching, where the engine has two or more potential meshes, one for each engine variant.

It might not be totally useful to do this because there's already so many engines available, but it would at least be cool to see in action. If nothing else, this could be really useful if/when you have to take the number of parts you have in stock into account (e.g. you have 5 LV-Ts in stock and they can be either great in atmo or great in vacuum, which may in turn require a change to how ISP is handled by engines).

This idea is getting more complex as I keep going on, so I'll stop now. Good idea, Tweeker!

[Tweeker]

I watched a video this weekend on the new B9 experimental, I noticed that they let you choose among variant parts by using a button in the tweakable menu for the part. So this would be basically the same.

I thought that you might differentiate between the variants by putting a stripe on the exhaust nozzle