Less DV to leave Kerbin?

[jalapen0]

I've noticed it takes about 300 to 500dv less to reach 100km orbit from Kerbin on 23.5. Has anyone else noticed this?

[FenrirWolf]

I don't suppose you've installed FAR, have you? If not then the design of your rockets and/or chosen ascent profile can all contribute to variance in delta-v expenditure.

[jalapen0]

no, no mods at all.

[KerbMav]

New engines strong enough to push against and so leave atmosphere faster?

[Red Iron Crown]

I guess the question is, are you using the same rocket and ascent profile in 0.23.5 as you were in 0.23? If you've built a new rocket with a greater TWR (certainly possible with the new parts), you might be wasting less dV to gravity drag in a more efficient ascent.

[cantab]

If it's with the new parts, then it's down either to having a greater TWR at liftoff, or possibly to differences between vacuum and atmospheric Isp and thus delta-V. The new four-engine cluster has a relatively small difference between its performance in vacuum and its sea-level performance compared to most older engines, which will result in using less vacuum delta-V, which is probably what you're reckoning things off. By contrast the KR-2L has a very large difference in performance depending on atmospheric pressure, so if you use it as a first-stage engine (which it's not meant for, but it looks the part for many rockets) you'll use more vacuum dV.

[AmpsterMan]

I haven't noticed this myself. Perhaps you've built a craft with better starting TWR. I used to have a rocket with starting twr of 1.2. It would use up about 300-400 more dv than my 1.8 craft. However, it did have about 800 more dv so the tradeoff was worth it.

[Shna_na]

Assuming that you have used the same rocket, my guess is that the increased stability of the new joints system has caused you to waste less delta-V on corrections (through gimballing or direction). Another possibility is that you're simply better at piloting the craft now. Did you have framerate issues before the update? Because if you did and if they were fixed by the new optimisation (mostly of the water) you may be performing better and the game may actually be rendering the physics more accurately. The update itself did not, however, tweak how easy it is to reach orbit (with the exception of new parts and improved parts).

[TheScareCake!]

Crap.

I lifted my transfer stage using my first stage, what should i do? :|

Yeah, in 0.23 it required more dv to get into the orbit...

[cantab]

Use your second stage as your transfer stage, I guess.

[Kasuha]

Some parts such as battery packs, RCS ports, or lights are now massless. That may reduce the dv you need to reach orbit if you're using dv calculator which does not yet know these parts are massless.

[Red Iron Crown]

Crap.

http://i.imgur.com/zSJLbN9.png?1

I lifted my transfer stage using my first stage, what should i do? :|

Yeah, in 0.23 it required more dv to get into the orbit...

How much dV did your first stage have, and how much is left?

[Guest]

Some parts such as battery packs, RCS ports, or lights are now massless. That may reduce the dv you need to reach orbit if you're using dv calculator which does not yet know these parts are massless.

Wait, what? Is there any indication of why that happened?

[Pecan]

http://forum.kerbalspaceprogram.com/threads/76173-Massless-parts

[TheScareCake!]

How much dV did your first stage have, and how much is left?

Dont know, mechjeb bugged up and it didnt show it :/

[Xavven]

I just ran a test, and it still takes about 4500 delta-v to get to a 100km orbit.

If you want to repeat my test, try this:

I had a probe core, a battery, and solar panels payload. The payload was 0.44 tons, and my lifter was two FL-T800 tanks with an aerospike, so I had consistent ISP to reduce errors in the calculation. The rocket has a delta-v of between 5007 (atmospheric) and 5032 (vacuum) m/s. After circularization, I had 35.55 units of liquid fuel left, equating to 483 m/s of delta-v. That means with my reasonably good, but imperfect, non-mechjeb assisted ascent, I used 4549 m/s of delta-v.

[thereaverofdarkness]

It takes about 4500 dV to leave Kerbin completely stock. If you meant to say it takes you 3000-5000 then I'd say you're doing fine, though you might check your dV calculations because it can't be done with much less than 4000. I've only used FAR for a little while now but it seems to me that I could get to Kerbin orbit with maybe as little as 3000 dV. It might be deceptive, however, since even though I get out of the atmosphere realy easily, I still need a lot of dV to reach orbital velocity.

[Claw]

Seems to take me about the same dV it always did. Although I haven't been building much yet with the new large parts yet, so maybe there is something wacky there.

BTW: MJ and KER are supposedly updated to take massless parts into account.