could someone make an "Advanced Rocket Engine" mod

[jab136]

the way that rocket engines currently work is that they have constant thrust, and a varying Isp with altitude, when in fact both will change. The Advanced Jet Engines mod already fixes this for jets, but rockets still have the issue. the correct model of rocket thrust when fully simplified is... thrust=mass flow rate*exit velocity+exit area*(exit pressure-ambient pressure), when you divide this value by the mass flow rate you get the equivalent exit velocity which when divided by the gravitational acceleration at the surface of earth which is 9.81 m/s gives you the Isp

[somnambulist]

I think KIDS or Real Fuels will do what you want

http://forum.kerbalspaceprogram.com/threads/52882-0-90-Kerbal-Isp-Difficulty-Scaler-v1-4-2-12-16-14

http://forum.kerbalspaceprogram.com/threads/64118-0-90-Real-Fuels-v8-3-Dec-20-14