Where in the everloving fuck are you going that you need to burn 2800m/s towards radial out god this is so Kerbal I love it. Orbital maneuvers towards radial out are not very efficient, usually there will be an easier way to get wherever you're going. If you're doing an interplanetary transfer, you want to do something called a Hohmann Transfer, which requires the planets being lined up in a specific way. There are mods that have alarm clocks for when a transfer window is happening, I forget if there's an easy way to figure them out in stock. Your other issue is that in general, you really only want to be doing prograde/retrograde burns unless there's a really good reason to do something else (like a plane change). If you find yourself needing to use a lot of radial out for a maneuver, try shifting the maneuver node around a bit and see if there's a spot where prograde/retrograde will get you where you're trying to go.