RAPIER into Scranjet

[Spricigo]

 

I have this idea to change the rapier to behave like a scranjet(just for personal use), problem is I have no idea how to do it. The problem its not knowing what kind of performance I want but rather knowing how to write the code/config/whatever to do it.

May someone help me? Either by pointing to a god scranjet mod or explaining what I need to do.

[dboi88]

1 hour ago, Spricigo said:

 

I have this idea to change the rapier to behave like a scranjet(just for personal use), problem is I have no idea how to do it. The problem its not knowing what kind of performance I want but rather knowing how to write the code/config/whatever to do it.

May someone help me? Either by pointing to a god scranjet mod or explaining what I need to do.

Looks like we might both have one half the solution. I've done some reading and can't really comprehend how a scramjet would behave differently to a rapier. If you could explain that i should be able to point you in the right direction for the actual configs.

[sebi.zzr]

1 hour ago, Spricigo said:

May someone help me? Either by pointing to a god scranjet mod or explaining what I need to do.

You sure do have more questions than answers.There is no such thing as "scranjet",closest to what Google could find was Scramjet.
R.A.P.I.E.R. is a sabre engine,but if you're looking for scramjet,you could make it yourself,with stock parts.
What you need is:Whiplash,Engine Pre-cooler and Shock Cone Intake.
And this is how yor "scranjet"shoud look:

[Spricigo]

@sebi.zzr please, go read the links you just throw at me. You'll notice that it don't fit your idea that a whiplash its a scramjet.

Also I want to modify the RAPIER into a different engine from what exist in the stock game , something I think its clear in my OP even using a foreign language to write it.

@dboi88 notice that I said I know the performance that I want, not if that performance world match the real world . That said, my idea of a Scramjet its somewhat close of the Rapier in jet mode but would need supersonic speed to start to produce thrust and maybe maintain performance at slighter higher speed. The fuel consumption should be higher than other jet engines.

[dboi88]

9 minutes ago, Spricigo said:

@dboi88 notice that I said I know the performance that I want, not if that performance world match the real world . That said, my idea of a Scramjet its somewhat close of the Rapier in jet mode but would need supersonic speed to start to produce thrust and maybe maintain performance at slighter higher speed. The fuel consumption should be higher than other jet engines.

Ok, either way i needed to know how they differed before i could suggest modifications, no offence intended. 

First you'll need to create a new .cfg for your part. Easiest way to do this is to copy the existing file Kerbal Space Program\GameData\Squad\Parts\Engine\rapierEngine\rapierEngine.cfg and rename it.

This is the part of the .cfg you need to edit.

name = RAPIER give it a new name otherwise it won't work, this is a name used internally by ksp

this below is then the part of the engine config you'll need to play with.

velCurve
        {
            key = 0 1 0 0.08333334
            key = 0.2 0.98 0.42074 0.42074
            key = 0.7 1.8 2.290406 2.290406
            key = 1.4 4.00 3.887193 3.887193
            key = 3.75 8.5 0 0
            key = 4.5 7.3 -2.831749 -2.831749
            key = 5.5 3 -5.260566 -5.260566
            key = 6 0 -0.02420209 0
        }

the first number in the section above for each line is the mach number the rest of the numbers are then related to thrust and isp , notice the curve in numbers up to mach 3.75 , then the drop off, you'll need to adjust that curve to match the performance you want, it might be useful to graph out the figures in excel, then then adjust the curve to match what you have in your head.  
        atmCurve
        {
            // higher thrust at altitude than even TRJ
            key = 0 0 0 0
            key = 0.018 0.09 7.914787 7.914787
            key = 0.08 0.3 1.051923 1.051923
            key = 0.35 0.5 0.3927226 0.3927226
            key = 1 1 1.055097 0
        }

this section is the same but for altitude, 0 = vacuum 1 = sealevel

 

[Spricigo]

4 minutes ago, dboi88 said:

Ok, either way i needed to know how they differed before I could suggest modifications, no offence intended.

No offence taken. In fact all I have to say is thank you.

 

[JadeOfMaar]

5 hours ago, dboi88 said:

Ok, either way i needed to know how they differed before i could suggest modifications, no offence intended. 

First you'll need to create a new .cfg for your part. Easiest way to do this is to copy the existing file Kerbal Space Program\GameData\Squad\Parts\Engine\rapierEngine\rapierEngine.cfg and rename it.

This is the part of the .cfg you need to edit.

name = RAPIER give it a new name otherwise it won't work, this is a name used internally by ksp

this below is then the part of the engine config you'll need to play with.

velCurve
        {
            key = 0 1 0 0.08333334
            key = 0.2 0.98 0.42074 0.42074
            key = 0.7 1.8 2.290406 2.290406
            key = 1.4 4.00 3.887193 3.887193
            key = 3.75 8.5 0 0
            key = 4.5 7.3 -2.831749 -2.831749
            key = 5.5 3 -5.260566 -5.260566
            key = 6 0 -0.02420209 0
        }

the first number in the section above for each line is the mach number the rest of the numbers are then related to thrust and isp , notice the curve in numbers up to mach 3.75 , then the drop off, you'll need to adjust that curve to match the performance you want, it might be useful to graph out the figures in excel, then then adjust the curve to match what you have in your head.  
        atmCurve
        {
            // higher thrust at altitude than even TRJ
            key = 0 0 0 0
            key = 0.018 0.09 7.914787 7.914787
            key = 0.08 0.3 1.051923 1.051923
            key = 0.35 0.5 0.3927226 0.3927226
            key = 1 1 1.055097 0
        }

this section is the same but for altitude, 0 = vacuum 1 = sealevel

 

@Spricigo you will also want to change title = CR-7 R.A.P.I.E.R. Engine

as well as that's the display name in the SPH or VAB. While the game can distinguish the two engines you may not be able to.

Asfor velCurve, the numbers are Mach #, Thrust multiplier, Tangent In and Tangent Out. The tangent values affect how smooth or sharp the curve bends as it approaches and passes a given point or key. I'm sure you already know that SCRAMjets normally don't work under certain speeds so when you add velCurve keys, you may want to start by changing the thrust multiplier at Mach 6 to a decent figure between 0 and 3, and end at the highest mach you want with a decent number fairly higher than 3.

For atmCurve, it's Atmosphere (I'm not sure what but I assume pressure), Thrust multiplier, Tangent In and Tangent Out. You use this to make or allow atmosphere pressure to affect performance independently or in parallel to speed. Some engines work better in soup-osphere, some engines work better near the edge of space. As suggested for velCurve, you can optionally raise the thrust multiplier numbers at all the keys here so that the tuned engine is overall more powerful regardless of speed at higher altitudes/less pressure.

Edited January 20, 2017 by JadeOfMaar

[FleshJeb]

This is very relevant:

 

[steedcrugeon]

Prakasa mod parts include scram jets and hybrid scram jet parts: