The Wolfhound and the Skiff's stats seem to be switched

[Tyko]

13 hours ago, OHara said:

Yes, I saw this and started writing the table intending to make a simple bug-report saying "please un-reverse them". 
Then I realized why KerikBalm, and others, say the swapped stats are not much better, and that comparison to real engines is complicated..

The AJ10-137 certainly looks like a vacuum-optimized engine, as if trying to optimize Isp in vacuum.  This real engine does the best it can with the long-storable, self-igniting,  low-energy-density, hypergolic fuel it had to use.  The J-2 gets its better stats mostly by burning cryogenically-stored liquid hydrogen.  KSP treats all fuels the same,  and give engines performance closer to that with hypergolic fuels. 

The engine masses do seem to be reversed, roughly.  Also J-2 analog needs more thrust, as you mentioned earlier regarding how they are used in an Apollo Saturn-V replica.

We still need to put something on the bug-tracker.  Maybe a link to this thread is the best.

Once Squad is finished with 1.4.x rapid updates I'm probably going to just make a config that works for me. A number of the other MH engines need tweaking too so they have their own niche.

[Mark Kerbin]

On 4/13/2018 at 2:34 PM, Tyko said:

Once Squad is finished with 1.4.x rapid updates I'm probably going to just make a config that works for me. A number of the other MH engines need tweaking too so they have their own niche.

Can you send that to me when you make it?

[Tyko]

1 hour ago, Mark Kerbin said:

Can you send that to me when you make it?

Sure, I'm concerned about posting anything because there will be many opinions as to what's "right"...my balancing will be more focused on making sure every engine makes sense and has a niche. I'll take a shot at it and see if I come up with something shareable

[KerikBalm]

Indeed, there will be many opinions about what is right... Like I already gave my opinion on this thread, but I doubt that your config would be very close to the MM config that I posted

[Tyko]

On 4/15/2018 at 5:54 AM, KerikBalm said:

Indeed, there will be many opinions about what is right... Like I already gave my opinion on this thread, but I doubt that your config would be very close to the MM config that I posted

I actually used your suggestions as a starting point. the biggest changes were that I left the Skipper with it's stock specs and I made changes to the KE-1. I increased its thrust to 1750KN to give it a niche separate from anything else. It's back to being the most powerful single-nozzle engine just like the F-1. I'll post what I'm working on later. It's not final, but am open to feedback

[sevenperforce]

23 hours ago, Tyko said:

I actually used your suggestions as a starting point. the biggest changes were that I left the Skipper with it's stock specs and I made changes to the KE-1. I increased its thrust to 1750KN to give it a niche separate from anything else. It's back to being the most powerful single-nozzle engine just like the F-1. I'll post what I'm working on later. It's not final, but am open to feedback

Is there a corresponding mass increase?

So...more thrusty than a Mainsail at SL but not as thrusty as a Rhino in vacuum, I assume?

[Tyko]

@KerikBalm, @sevenperforce

I've made a lot of progress today. The current config file is in the spoiler below. Here's a link to the Google Sheet I'm using to track and compare:

https://docs.google.com/spreadsheets/d/1tzovHSBZm_4_xLrglqAKbmLzeGQozpZfQr2YAaOTs8k/edit?usp=sharing

My (pseudo) logic:

1. Build rockets that look like reasonable analogs of RL rockets - this is called Making History, so I'd expect to be able to piece together something that looks right
2. Adjust the engines so that they can fulfill their historical role on each rocket.
3. Take another pass to make sure each engine fills a niche.
4. Since all rockets are a bit over-powered in Stock scale I used a target of 5000 d/v to orbit because that's what it takes in a 2.5x universe. I've read many times on the forums that 2.5x with stock parts is a lot closer to IRL balances. By balancing it against 2.5x I'm attempting to mirror the same degree of "over-poweredness"  that is designed into stock engines.

NOTES:

1. With these engine configs a Saturn V analog can put approx. 60 Tons into LKO or about 30 Tons on TLI.
2. I removed the Poodle entirely and applied the Poodle stats on the Wolfhound - The Poodle is incredibly useful, but the model is way out of date and doesn't even look like a high-efficiency vacuum engine.

 

Spoiler

@PART[LiquidEngineKE-1] // Mastadon
{ 
    @mass = 7
    @MODULE[ModuleEngines]
    { 
        @maxThrust = 1750
        !atmosphereCurve
        atmosphereCurve
        {
            key = 0 295
            key = 1 285
            key = 20 0.001
        }
    }
}
    
    
@PART[LiquidEngineLV-T91] // Cheetah
{ 
    @mass = 1
    @MODULE[ModuleEngines]
    { 
        @maxThrust = 165
        !atmosphereCurve
        atmosphereCurve
        {
            key = 0 335
            key = 1 100
            key = 6 0.001
        }
    }
}

@PART[LiquidEngineLV-TX87] // Bobcat
{ 
    @mass = 2.5
    @MODULE[ModuleEngines]
    { 
        @maxThrust = 600    
        !atmosphereCurve
        atmosphereCurve
        {
            key = 0 310
            key = 1 275
            key = 6 0.001
        }
    }
}
        
    
@PART[LiquidEngineRE-I2] // Skiff
{ 
    @mass = 3.15
    @MODULE[ModuleEngines]
    { 
        @maxThrust = 670
        !atmosphereCurve
        atmosphereCurve
        {
            key = 0 370
            key = 1 110
            key = 6 0.001
        }
    }
}
    
-PART[liquidEngine2-2]:FINAL {} // Remove Poodle. The model is my least fav and it doesn't look like a highly efficient vacuum engine - the nozzle is all wrong.
    
@PART[LiquidEngineRE-J10] // Wolfhound - replace stats with Poodle.It's a tested and proven engine but the Wolfhound model is so much better

{ 
    @mass = 1.75
    
    !MODULE[ModuleEngines] {}
    
    MODULE
    {
        name = ModuleEngines
        thrustVectorTransformName = thrustTransform
        exhaustDamage = True
        ignitionThreshold = 0.1
        minThrust = 0
        maxThrust = 250
        heatProduction = 83
        fxOffset = 0, 0, 0.4
        EngineType = LiquidFuel
        exhaustDamageDistanceOffset = 1.75
        PROPELLANT
        {
            name = LiquidFuel
            ratio = 0.9
            DrawGauge = True
        }
        PROPELLANT
        {
            name = Oxidizer
            ratio = 1.1
        }
        atmosphereCurve
        {
            key = 0 350
            key = 1 90
            key = 3 0.001
        }
    }
//    @MODULE[ModuleEngines]
//    { 
//        @maxThrust = 325
//        !atmosphereCurve
//        atmosphereCurve
//        {
//            key = 0 340
//            key = 1 70
//            key = 6 0.001
//        }
//    }
}

    
@PART[LiquidEngineRK-7] // Kodiak
{ 
    @mass = 1.5
    @MODULE[ModuleEngines]
    { 
        @maxThrust = 280
        !atmosphereCurve
        atmosphereCurve
        {
            key = 0 320
            key = 1 280
            key = 20 0.001
        }
    }
}
    
    
@PART[LiquidEngineRV-1] // Cub
{ 
    @mass = 0.16
    @MODULE[ModuleEngines]
    { 
        @maxThrust = 35
        !atmosphereCurve
        atmosphereCurve
        {
            key = 0 320
            key = 1 270
            key = 20 0.001
        }
    }
}
    
    
@PART[engineLargeSkipper] // increased mass and max thrust. Made a niche for the Skipper
{ 
    @mass = 3.9
    @MODULE[ModuleEngines]
    { 
        @maxThrust = 975
    }
}

 

Edited April 19, 2018 by Tyko

[Tyko]

I released my changes in this Mod:

 

[klesh]

On 3/22/2018 at 11:41 AM, klesh said:

...However, as it stands now the Wolfhound's ISP vs the Poodle seems kinda "in the same league", certainly when compared to the Skiff.  

Poodle ISP:  asl-90, vac-350

Wolfhound ISP: asl-70, vac-412 

So a little worse in atmosphere and a little better in space. Ok, alot better.  Asl-70, vac-370 is maybe a little more reasonable (-20/+20)? 412 is pretty high.

 

Skiff, meanwhile is clearly designed to be in the atmosphere:

Skiff ISP: asl-265, vac-330

 

I can't look at those numbers and say they engines are mistakenly switched. That looks like pretty much like they intended them to be.

 

 

Okay so SQUAD revised some of the numbers here, looks like they went with something close to my suggestion of 70/370 and ended up giving the Wolfhound a debuff to 70/380 for ISP, thrust stays the same, mass went up from 2.5t to 3.3t. 

The Skiff ISP and thrust remains unchanged as far as I can see, and the mass went down from  2t to 1.6t.

 

 

In the end it's safe to say this wasn't a mistaken swapping of files or data.  I'm glad they took the time to revisit these and try again to balance them.

[Maxsimal]

On 12/20/2018 at 7:26 PM, klesh said:

 

 

Okay so SQUAD revised some of the numbers here, looks like they went with something close to my suggestion of 70/370 and ended up giving the Wolfhound a debuff to 70/380 for ISP, thrust stays the same, mass went up from 2.5t to 3.3t. 

The Skiff ISP and thrust remains unchanged as far as I can see, and the mass went down from  2t to 1.6t.

 

 

In the end it's safe to say this wasn't a mistaken swapping of files or data.  I'm glad they took the time to revisit these and try again to balance them.

It's worth noting that while the original point of the MH engines was to create real-world analogues, this rebalance was more about doing the minimum amount of change to put things in balance.  So regardless of any real world analogue, the Wolfhound was going to remain as a high-efficiency Vac engine - just with more balanced stats.

But, as people have noted - KSP doesn't have the sort of tradeoffs in fuel types for LFO engines that exist for real-world engines, nor does it have reliability concerns with different engine cycles.  So trying to have a 'realistic' SPS engine - one where the efficiency was traded off for a reliability and not having them boil off - just isn't really possible, no one would use that engine when the Poodle is there.