Displacement isn't as much as a limiting factor, as the components in the motor and how stout the motor is. Audi's 1.8L has pushed out over 1200hp. For the Gen 1 motors we don't how much the bottom end can stand up to. The Gen2, Trifecta has already pushed almost 200whp and 200ft-lbs of torque out of it. I think these little motor are stout.Welcome to the forum!
There's only so much power you can squeeze from an engine that only has 1,364cc displacement. BNR offers a tune and turbo upgrade that helps extract more power. Keep us posted on your efforts, especially if you get the chance to put it on a dyno, I'd love to see what kind of numbers are possible!
BNR GTX14 1.4T Turbocharger Kit