What is the engine with most thrust?

[SansYT15]

Hello, I'm making a Lockheed SR71 and I cant it go quite to mach 3.5, does anyone know a mod for a good engine or the best engine to use?

[James Kerman]

Welcome to the forum @SansYT15.

I've moved your question to gameplay questions and answers. The wiki has good information on jet engines in the stock game.

[Empiro]

The Whiplash should be able to easily accelerate you to mach 3.5 and beyond. In stock KSP, the Whiplash has the best performance around 12.5km, though you should be able to hit mach 3.5 at higher altitudes as well.

[Aeroboi]

On 6/25/2019 at 8:51 PM, SansYT15 said:

Hello, I'm making a Lockheed SR71 and I cant it go quite to mach 3.5, does anyone know a mod for a good engine or the best engine to use?

Jet speed involves 3 things.

Jet thrust!
Aerodynamics!
and Wing incidence.

Jet thrust should be about 15Ton per Whiplash, you can do up to 25 Ton but then you are tweaking every optimization there is so stick to 15Ton.
Aerodynamics: Use as few stacks as possible. One stack is a single end to end fuselage. Try to use only tapered ends like 1.25 to 2.5m or 0.625 to 1.25m. Dont put external parts unto the plane except wings, landing gear and a ladder (optionally) all the rest in cargo bays or you suffer drag and wont achieve the speed you want.
Wing incidence is the angle of the wing versus the chord line. Using the rotation tool in the editor you can rotate the wing so that it moves slightly up at a incline. This means the plane does not need the same pitch, or none at all so it can keep the nose staying at prograde for reduced drag.
 

Edited June 28, 2019 by Aeroboi

[Aegolius13]

What is the engine with most thrust?

The Mammoth. (rimshot)

As mentioned above, the Whiplash is the go-to engine for this, and is almost certainly a copy of the SR-71  Improving aerodynamics is the most likely to help at this point.  But if you find you need even more high-speed performance, the other option is the Rapier, which can go higher and faster.  But it's not so good until you hit ~450m/s or higher.

[SansYT15]

Thanks, I'm right now bringing it from 306 tons to 15 Tons, btw should I take fuel out?

[Aegolius13]

4 hours ago, SansYT15 said:

Thanks, I'm right now bringing it from 306 tons to 15 Tons, btw should I take fuel out?

Unfortunately that's not a question that we can answer without knowing a little more about the ship.  Can you post a screenshot?  It would also help to know more about what you want to do with it.  If you only plan on flying it around for a few minutes, you don't need much fuel at all.  But if you're trying to fly all the way around the planet or something, of course much more would be needed.

[SansYT15]

I'm in Florida  so I will post one asap, it will be in 3 days, need a vid too? I happen to be a ytber so I got so rec software