2 Aerospikes or 4?

[RedeyePete]

I'm sending a plane to fly around on Eve (not to space)

Has own refueling.

It flies ok on Kerbal with 2 Aerospikes.

For those who know Eve better, should I take 4 instead?

Weight is 31t

[RedeyePete]

2

[Foxster]

I'm uncertain about the engines. Best bet is HyperEdit your craft there and test it. 

One important thing to know about Eve is that it's atmosphere is soup. That means you get extra lift and so need less lifting area than Kerbin, but it also means that drag is very high. I suggest remaking your aircraft so that it doesn't use mk2 parts, has the minimum number of stacks and that you ensure there are tapered pieces on the back of all the stacks. 

E.g...

Edited June 10, 2018 by Foxster

[Laie]

I'm afraid you'll be disappointed no matter what. As Foxster said, the atmo is soup, the drag is horrible. You won't get very far (or fast) until fuel runs out. If you're patient, you can glide a fair bit -- but then, average speed will be not all that much faster than a rover.

[Snark]

Yeah, Eve is absolutely horrible for exploring around the surface, at least in stock.

There are mods that include jet engines that work with other atmospheres (e.g. Kethane, Karbonite), and if you're using one of those, then it's not that different from exploring Kerbin in a jet plane.  There are also mods that provide electric-powered propeller propulsion (haven't used myself, sorry, don't know the name, but I know they're there).  There have also been mods that included nuclear-powered jets that require no fuel (i.e. just use atmosphere for reaction mass), such as Atomic Age (may it rest in peace).

But in stock:  purely rocket-powered LFO flight on Eve for exploration?  Yeah, it's ugly.

[ArmoredLipid]

Aerospikes are efficient atmospheric engines, but not exactly the strongest, so you might want to try a different approach. The S3 KS-25 "Vector" LFO engine has (a) better thrust at 1 Kerbin. atmosphere - 782.98 kilonewtons, in fact - (b) 5 more ISP at 1 Kerbin atmosphere - and (c) a gimbal, and one of the best in the game at that. It does weigh 4 times as much, however, so consider putting only 1 on your craft. Either way, one KS-25 is worth 4 Aerospikes weightwise and worth a little over 6 thrust-wise, so add (d): better TWR.

Edited June 19, 2018 by ArmoredLipid
Clarification.