How do I make an engine use a resource, but not have it factor into Isp?

[Nnimrod]

For engines that are pressure fed, or use a separate fuel for the turbine gas generator, like A-4 derivatives. I can just add it as another propellant, but then it affects Isp.

[JadeOfMaar]

@Nnimrod There are two ways you can approach this:

1. Have the pressurized resource be massless.
2. Add this line ignoreForIsp = True into the PROPELLANT node for this resource in the engine. All jet engines should have this line in the PROPELLANT node for IntakeAir.

[Nnimrod]

6 hours ago, JadeOfMaar said:

@Nnimrod There are two ways you can approach this:

1. Have the pressurized resource be massless.
2. Add this line ignoreForIsp = True into the PROPELLANT node for this resource in the engine. All jet engines should have this line in the PROPELLANT node for IntakeAir.

ignoreForIsp = True Well damn that's perfect. Thanks