Can't for the love of Kraken make the engines from KSP Interstellar modpack work properly, i always only have a few tens of deltaV in vacuum. (more in comment) : r/KerbalSpaceProgram
1.8.1 - 1.12.5] Interstellar Fuel Switch (IFS) 3.29.5 - KSP1 Mod Releases - Kerbal Space Program Forums