The 1.25m engines suck... Bad.

[SlabGizor117]

The relative TWR of engine thrust to how many tanks it can lift, compared to 2.5m parts, is terrible.  I had two full size 1.25m tanks with a swivel and it was like, a 1.05 TWR.  So I put a vector on it and it was somewhere around 4.  If the rocket was rebuilt with its 2.5m counterpart pieces, the TWR of the first stage would probably be around 2.  Why are the Swivel and Reliant so bad??

[numerobis]

You had 8.5t of tanks and 1.5t of engine, about 200 kN of thrust, and TWR of 1.05? That means you had about 9.5t of payload. That's a lot of payload for that engine. You know what you need?

MOAR BOOSTERS.

[oglommi]

Payload is to heavy. Just strap some SRB to the sides and you'll do fine.

[bewing]

The swivel and reliant are the very lowest tech engines on the tech tree for a reason, ya know. But if you look beyond just blasting a hole through the vacuum, IIRC the terrier has the best ISP of any LfOx engine. (It's also nice and short, which is convenient on lander designs. )

[godefroi]

What I think I heard you say is, "TANKBUTTS NEED TO GO!"

[Scotius]

Vector is overpowered And Reliant and Swivel are first tier engines for a good reason. Still, they are good enough for up to Mun missions (if you don't want to do biome-hopping), and even in late game they are good enough for Kerbin satellite launchers (they are cheap )

[godefroi]

Vector is overpowered like RS-25 and RD-180 are in real life... Powerful, efficient, complex, high technology, expensive engines. There's room for powerful engines, that are very expensive and show up at the end of the tech tree.

[tomkpunkt]

You forgott to calculate the price per ton of cargo. 

[moogoob]

I sometimes use a cluster of 3 or 4 Thuds to launch Size-1 boosters. More boosters, sir!

[MalevolentNinja]

I don't understand. Are you asking why a larger, 2.5m fuel tank and engine will lift the same payload better than a 1.25m tank and engine? That seems to be a silly question...

[Temeter]

Vector isn't owerpowered in terms of thrust to weight, it's exactly the same as a Mainsail. You missed that it weighs 4 tons, compared to 1.25 and 1.5 for reliant and swivel. It's a 2.5m level engine in 1.25m size.

If you want an equivalent high tech 1.25m engine, there is the aerospike which outperforms both engines (w/o alternator/vector thrust).

Edited March 28, 2016 by Temeter

[panzer1b]

I dont even understand why people try to compare the vector to the LVT series engines or any other 1.25m engine.  Profile aside, it is for all intents and purposes a 2.5m engine, period.  The "normal" 1.25m engines all have their uses.  The aerospike and 909 are byfar the best space engines, with the aerospike giving very solid TWR with a decent weight, perfect for starfighters and anything hat needs to go very fast very quickly, and its also the best 1.25m landing engine since not only is it high TWR/efficient, but it actually works well in atmosphere.  The lv909 though is probably the best vaccum engine if you arent going to go all out nuclear and just not give a crap about fuel/range.  As for the LVT30/45, i agree they are situational, but for my gameplay i use them for situations where i need 175-180 kN thrust but dont want to use the aerospike for whatever reason (say its a faction that i intend to be low tech like pirates or something and they cant use aerospikes).

Other then that, there are very few engines that i dont use at all.  A few that would fit the bill are the small radial engines (only thing i even touch em for are ground based guided missiles since i cant use a inline engine because of the new engine damage mechanics and i'd destroy the missile battery with inline engine).  Also dont use the mainsail anymore (if i actually have something anywhere near the size that id even use such a powerful engine id be better off with the 3.5m engines), dont use poodle much (only fuel barges use em since they are perfect size/thrust for that application, useless anywhere else), and honestly ive not yet seriously used the vector for anything (overkill thrust for anything i make, with the highest tonnage of a single ship i have currently in use being ~300t, a 500kN engine is plenty, let alone this monstrosity).

Perhaps the 1.25m engines could use a balance pass, but i think everything is reasonable (at least in career where funds do matter).  In sandbox well yeah, certain engines (unless you actually want to use them due to aesthetics or something) are redundant and you really only use the aerospike and lv909 for 1.25m craft, all other 1.25m engines are redundant or inferior to these 2 (only if you need a gimbal would the lvt45 come in handy, but i rely on reaction wheels anyways so not useful).

[Rocket In My Pocket]

I hardly ever use the Swivel, but the Reliant is exactly as it's name implies.

A reliable, dependable, work-horse engine that does a lot of heavy lifting during the early career and even finds uses later on.

If it was any better, what would be the point of getting the bigger engines further down the tree? I suppose as others have mentioned the real question here is "are we balancing the game for sandbox mode where every part should have it's place, or are we balancing for career mode where they should improve somewhat as the game goes on?"

[InterCity]

I don't think 1,25m engines suck. On the contrary, i find the aerospike to be one of the best engines in-game, and swivel is a good engine for smaller missions. Granted, compared to the mainsail they suck as lower stage engines. Take them to orbit, though, and you'll see their true power.

Until then, you basically have one five options:

1. Boosters!
2. More boosters!
3. Ridiculous amount of boosters!
4. Ludicrous amount of boosters!
5. FIRE ALL THE BOOSTERS!!1!!1!1!!1!!1!!!1!!1

[wumpus]

The two 1.5 engines are simply given to you at the start of the tech tree.  Don't expect much.

On the other hand, the LV-909 ("terrier") remains one of the best engines throughout the entire game (even after being nerfed in an atmosphere).  The poodle might have a slight advantage in TWR, but typically where the LV-909 shines the advantage in mass simply overwhelms it (the poodle's mass puts it closer to the "nerv" which is simply the way to go if you can afford the mass).

The biggest issue with the reliant/swivel is that you can typically get cheaper delta-v via SRBs (especially at that tech level).  Typically the rockets are small enough that the capsule torque can control SRBs, and once they burn out there often isn't a window where the LV-909 isn't the better choice.

[numerobis]

Among bipropellent engines, the reliant is the cheapest engine per vacuum kN (5.12 funds per kN). So don't knock it as a launch engine! It's way cheaper per kN than the mainsail (but slightly worse Isp), and a bit cheaper than the twin-boar with identical Isp.

The poodle is a close second (5.2 funds per kN) in vacuum but is terrible at low altitude; the twin-boar in third place (5.625 funds per kN).

If you're discarding the stage, price matters.

The aerospike is the most expensive, at 21 funds per kN. You're best to land on it so you can get your money back!

[Renegrade]

28 minutes ago, numerobis said:

Among bipropellent engines, the reliant is the cheapest engine per vacuum kN (5.12 funds per kN). So don't knock it as a launch engine! It's way cheaper per kN than the mainsail (but slightly worse Isp), and a bit cheaper than the twin-boar with identical Isp.

Totally agree - the price/performance keeps the low-tier engines in play long after higher nodes have been purchased.  Also, it's kinda fun to use a LV-T30 or 45 in an upper stage for some crazy TWR from time to time.

2 hours ago, panzer1b said:

In sandbox well yeah, certain engines (unless you actually want to use them due to aesthetics or something) are redundant and you really only use the aerospike and lv909 for 1.25m craft, all other 1.25m engines are redundant or inferior to these 2 (only if you need a gimbal would the lvt45 come in handy, but i rely on reaction wheels anyways so not useful).

^ this and this v

1 hour ago, wumpus said:

The biggest issue with the reliant/swivel is that you can typically get cheaper delta-v via SRBs (especially at that tech level).  Typically the rockets are small enough that the capsule torque can control SRBs, and once they burn out there often isn't a window where the LV-909 isn't the better choice.

I hope y'all realize how #lolfake the reaction wheel torque in KSP is.. >.>

[wumpus]

6 minutes ago, Renegrade said:

I hope y'all realize how #lolfake the reaction wheel torque in KSP is.. >.>

And having engine gimballing being cheaper than ailerons is oh so much more realistic?  Even the kickers don't get beyond the atmosphere.

[katateochi]

I really like the T45 and T30 (sorry, swivel and reliant), they're low cost and versatile - mostly as launch engines, but also good for some lander styles, and are ok transfer stage engines (if you want short burn times and don't mind being a bit OTT on fuel).

But they don't like being alone, their real potential is unlocked when you cluster them. One of my 40-ton payload lifters (this one) is inspired by the Delta-IV, but rather than using 3 mainsail engines it uses 18 T45s and 3 T30s setup as 3 clusters (each cluster has a central T30 surrounded by 6 T45s). 
3x Mainsail costs 39000
18x T45 + 3x T30 costs 24900, that's a saving of 14100, with which you could buy a mainsail and a T30. 

But not only does it have a lower launch cost than it would if it used mainsails, it's also very, very responsive; those 18 T45s gives it a very high level of control, no need for fins and it only has 1 advanced SAS module, but it's so easy to fly and stable my dog could operate it (well maybe not, but that's more a dog-keyboard interface problem).  
(That lifter was made back in 1.0.2, but still works in 1.0.5)

For smaller lifters I like using pairs or triples of T30s with a central T45 and I also like the T30 as 2nd phase engines on SSTOs. 
No, I think they're great little engines!

 

[Renegrade]

Just now, wumpus said:

And having engine gimballing being cheaper than ailerons is oh so much more realistic?  Even the kickers don't get beyond the atmosphere.

Compared to the reaction wheels, yes, yes it is.  The next logical step for the reaction wheels is to give them a mana bar, and let them teleport you from place to place with a goddamn spell.

Not to say that there aren't some serious cost errors in the aero section of the game, of course (I think most of the parts are basically 500 funds because that's the default value from Harv's cut-and-paste or whatever fubar was going on at that time).  But the error is probably what, 5x?  10x?   That's a very serious error, but the reaction wheel error is something like 100x to 1000x (depending on whether they're actually CMGs or reaction wheels)...

[TK421d]

"vector is overpowered"

Saying this is like comparing a Shelby Cobra to a Model-T, or a modern PC to an Apple-II. is modern PC overpowered?  no.

[Scotius]

I thought we were comparing Vector to Reliant and Swivel? Anyways, i use both of them on my heavier 1,25 m launchers early in the Career. Swivel in the central stack provides extra control with its gimballing. Reliants on the side boosters provide that extra 'oomph'. High in the atmosphere Swivel can comfortably push lighter payload to orbit.

[numerobis]

The vector is the second-most expensive engine, nearly as much as the aerospike. That kills it for a cost challenge.

In the payload fraction challenge, though, the vector wins handily due to good TWR and high Isp. Only the mammoth can beat it -- but it's just four vectors strapped together, sharing a bit of mass.

So the 1.25m engines are the cheapest, the most efficient, or nearly the lightest among atmospheric bipropellant engines.

The SRBs are all also 1.25m, and they're the cheapest thrusters by far for launch.

[zarakon]

16 hours ago, Scotius said:

And Reliant and Swivel are first tier engines for a good reason. Still, they are good enough for up to Mun missions (if you don't want to do biome-hopping), and even in late game they are good enough for Kerbin satellite launchers (they are cheap )

A single Swivel/Reliant -> Terrier -> Ant/Spark stack is also enough for landing probes on Ike, Duna, Gilly, and maybe even some of the Joolian moons

[Scotius]

Yeah, well - i like to build big Recently i've built a nuke-powered lander with 4000 m\s dV Is it going to Duna? Nope - biome-hopping on the Mun.