[Balance] Chemical Engine viability

[Syrcan]

In this issue I want to address the fuel, combustion promotor consumption rates, and power production of the Chemical Engine, along with a comparison with the existing LCE and ECE (Large Combustion Engine and Extreme Combustion Engine).
Along with two other people, we have checked the code, done math and checked in-game to assure our results do match our calculations and expected outcome.

This issue concerns Combustion type fuels, but by extent it can also apply to gas fuels.
I will be referencing to an issue currently existing in the GTNH github about the ECE, which can be found here: GTNewHorizons/GT-New-Horizons-Modpack#7134. The summary of that issue is that the ECE supposedly consumes too much LOX, and is not worth it due to 100% fuel efficiency even when boosted (despite listing 400% in the tooltip).

Back on topic:
Our main goal was to compare the Chemical Engine with the ECE. With some calculation, we have determined that the ECE consumes 379L/sec of HOG per second, with the 320L/sec of LOX indicated, when boosted.
We adjusted the Combustion Promotor rate to 160L/sec which corresponds to 320L/sec of LOX.
Our test results:
Chemical Engine power output: 11277EU/sec (expected /tick, that's been reported in #3 and fixed by the time this is sent)
Chemical Engine fuel efficiency: 34.4%
Our conclusion:
To no surprise, disappointing. ECE is considered very far off meta due to the issues listing in the other issue, and we have here a multiblock performing a lot worse.
In comparison, two LCEs output 12288EU/t at 150% fuel efficiency, and does not require LOX at all. And even that multiblock doesn't seem to be a big appeal to GTNH players, as far as I am aware.

So naturally the next part of the tests come with increasing The Combustion Promotor. As the Chemical Engine is meant to produce unlimited power, let's crank the numbers up. Let's aim 131k EU/t (1 ZPM Amp) using HOG, with 90% efficiency (as 100% is unreachable).
This brings us to approximatively such numbers: 1680L/sec HOG and 7190L/sec Combustion Promotor, which is 14380L/sec LOX!! These are verified numbers. For reference, a ZPM powered Mega Vacuum Freezer only makes 4266L/sec LOX (256x cells per 60sec).

TL/DR:
Under the current implementation, if a player wanted combustion fuel to power their base, they would be better off spamming LCEs, by a landslide.

Our suggestions:
Tough to say, this is a balance issue. In my opinion this type of generator should be able to easily go over 100% fuel efficiency to make up for the investment in Combustion Promotor. The latter fluid consumption rate could also be lowered in order to reach those high efficiencies.
We believe the same type of issue appears with Gas type fuels, but we haven't done any testings on them to present any numbers.

[GlodBlock]

yeah, you are right, it consumed too much liquid oxygen. i can change the efficiency coefficient to reduce the liquid oxygen use.
as to whether this mulit's efficiency should go over 100%, most generators in GT5 have lower efficiency if they have higher output voltage, i am afraid it maybe imbalanced.

[Syrcan]

This is a valid point. I know you and the gtnh team are very concerned about avoiding making things overpowered.

I however still have to express my own concern about repeating the ECE situation, or even mistake if I dare to say. I am pretty confident players are eager to try different power options that are actually worth it, over the standard "fluid nukes". Since I am not a known face, it would probably be better to have regulars voice themselves regarding this.

[GlodBlock]

I am pretty confident players are eager to try different power options that are actually worth it, over the standard "fluid nukes".

That is also what I believe in. I think I should't be conservative about balancing.