What is the difference between RAM intakes and Shock Cones?

[Falkenherz]

I have not achieved the tech level for Shock Cones yet, but since the RAM intakes are already working so well that I basically don´t need to stack more, why would I need shock cones? I understand that my current turbojets just have power up to 17km; is that because of the RAM intakes giving up at that height? Could I thus go higher with turbojets once I have Shock Cones? Asking hypothetically the other way around; would Rapiers, which supposedly have power still at 20km, also work with just RAM intakes instead of Shock Cones?

Edited June 4, 2015 by Falkenherz

[n0xiety]

Just so you know rapier works better at high altitude and speeds passing 1000m/s. I have planes that can go over 30k and stay there with 1400m/s. I use the ram with an engine cooler generally. I don't know why but engine cooler works great at high altitude or i feel like it does. I really feel like the engine cooler takes the heat from the intake its connected to and radiate it much faster. The main difference between ram and shockcone i see is that the ram is lighter and more temperature resistant. But don't let this fool you because it really doesn't matter that it has more temperature ressistance since it is lighter and has less heat conduction to the part it is connected to, thus the ram intake generally is the first thing to overheat and explode. When shock cone used the advanced nosecone gives up first.

[Ferdoni]

Schock Cones have an intake speed of 12 while the RAM has only 10. The ram is 10% better in surface and intake but loses it advantage at higher speeds.

[waterlubber]

Shock cones also are much less draggy, allowing you to crack the sound barrier easily.

[Ferdoni]

Shock cones also are much less draggy, allowing you to crack the sound barrier easily.

They produce the same amount of drag... both 0.3

[n0xiety]

Hah just did some tests on this and heres what i found. Shock cone is better than ram in terms of drag. The difference is quite alot actually. For reducing the tail drag you can place a shock cone over rapier and then clip the shockcone inside the engine untill you can't see the white part at the side of the shock cone. Don't clip more than that. This will allow the thrust to pass from openings of the shockcone and reduce the tail drag + it will give you some more air for high altitudes. Try it i know it sounds strange but it actually works something like rapierspike.

[Warzouz]

And what do you think of structural intakes ?

Further more, I'm not sure the open/close do anything anymore. Drag is reporter lower, but the "red spike" is still the same.

[n0xiety]

And what do you think of structural intakes ?

Further more, I'm not sure the open/close do anything anymore. Drag is reporter lower, but the "red spike" is still the same.

I need to test structural intakes but i kinda like the engine precooler. I feel like it takes away the heat from the shockcone and directs it onto other parts which in turn allows more time while you are gaining speed under 20k. Oh just noticed that the clipped shock cone i mentioned before does improve stability too. Had a very unstable plane and now it seems to be quite stable with the clipped shockcone over rapier. Further testing needed for sure. But the clipped shockcone shows its benefits after you pass 500m/s. Before that it slows you down a bit because of the extra weight but after you pass that point the gain is about %10.

[Geschosskopf]

And what do you think of structural intakes ?

Understand that only 2 things matter about intakes: intake area and drag. The amount of IntakeAir resource is pretty meaningless. Jet engines consume 2 resources: LF and IntakeAir. The game thus handles IntakeAir just like any other fuel, meaning you need a "fuel tank" of IntakeAir. That's what the IntakeAir capacity of an intake is, the size of this "fuel tank". So basically, all intakes are "fuel tanks" that grow their own "fuel". The bigger the intake area, the faster the intake "grows" IntakeAir in any given set of circumstances (altitude, speed, etc.). As long as the intake "grows" IntakeAir faster than the engine consumes it, the engine will keep running, and the size of the "fuel tank" doesn't matter. Once the air gets so thin that production is less than consumption, the engine will flame out very quickly because the total "tankage" of IntakeAir from many intakes isn't big enough to keep it going more than a few seconds.

Then there's drag, which you can't see without looking at part config files. Drag limits both speed and acceleration. Too much drag and you can't go supersonic at all, and in any case more drag means more time needed to reach any given speed, which means more fuel consumed, which means maybe not reaching orbit.

As things stand now in 1.0.2, the ram intake has a slightly higher intake area than the shock cone, but the shock cone has a bit less drag and can stand higher temperatures. Assuming you fly a good ascent path, the temperature should never be an issue with either, so it comes down to intake area vs. drag. This means that a ram intake can fly slightly higher than a shock cone but the shock cone has an easier time getting there. In practice, however, I haven't noticed any significant difference between them. The same ship, differing only in the type of intake, flies essentially the same. Thus, for actual intake use, it's really just a question of aesthetics. That said, as others have mentioned, the shock cone can be used as a tail cone for drag reduction. But as for actual use as an intake, it's really a matter of taste.

Now as to the structural intakes, with 1.0.2 air, both structural intakes and the old "hood scoop" radial intakes are bad for supersonic planes. They add far more drag than their miniscule extra amount of intake area is worth. I only use them on subsonic planes as their only intakes. If you need a bit more intake area for your SSTO, it's way better to use the "precooler" than structural intakes. More intake area for less drag, plus a bit of extra fuel. And note, the "precooler" does NOT have anything to do with cooling. It's just another type of 1.25m inline fuel tank with an intake on it. It's just got straight sides so is more friendly to radial attachment, and less drag than the other types of fuel-tanks-with-intakes.

[Warzouz]

Ok, my SSTO uses 2 ram intakes and 16 structural intakes for 2 rapiers and 1 turbojet. I think I've to change that... But I don't know where to put them...

I could replace 2 ram + 16 structural with 4 shock cones.

Edit : That reduces the drag coef from 23.6 to 18.2 (MechJeb info) but increased mass by 350kg (out of 36T)

Edited June 5, 2015 by Warzouz

[n0xiety]

Structural intakes are really bad drag wise for what they give. They are terrible actually. I am using shock cone from now. Another thing is that you should try the clipped shock cone over rapier that i told you about it really adds to performance.