Denmark

[NoHachi]

I once modified a car from 90 stock bhp to 130bhp. Thats a rise of 40bhp or 45%. It wasn't that spectecular to begin with and in about a week most of the novelty had worn of. It could be just me ofcourse..
I also had a similar car to that one (the engine donor) for about a month, but it had a modified suspension. The grin lasted until the day I tore it apart for the engine.

General suggestions for building an all-out go-hachi:
Minimize weight (carbondoors etc look cool aswel as being wonderfully light..might be a bit expensive though.

More importantly, minimize weight where it counts: unsprung weight. The influence is about 3-4 times the influence of sprung weight. Sadly, every solid axle vehicle suffers on this front. Places to improve upon:
Light rims: biggest gain to be had here. Large expenses as well (eg. volk TE37 deepdishes)
Alloy multi pot brake callipers. 2 piece rotors with alloy hub.
Alloy monotube shocks. billstein springs to mind. Affordable as well.