The first thing you need is population, a small capital can never have enough people to work all the mines and specialists you need to get high production. So, to get really good production, make sure to feed food caravans into the capital as soon as possible to get decent pop.
For inspiration, two screenshots from my recent DCL Russia game. That game had a really good production capital, and of course the +1 hammer on strategic also helps a lot. Note that I'm not a top player, so I'm sure a really dedicated spammer would get more out of it, probably mainly by simply having higher pop:
t138, 26 pop, 68 production, new wonder (taj mahal) 10 turns
t174, 32 pop, production 163 (boosted by GA, hydro plant, chemistry, new wonder (christo redentor) 8 turns