what engine is ur 1.0?
honestly 1.6" is too big, mine is kelisa and used to have 1.6" piping and sflow and it is not fast at all, pickup is fairly good but later on high gear felt like driving lorry, slow and no torque boost at higher rpm, FC becomes higher because i kept on pushing the car as it wont accelerate faster at high gear speed, it was worst than my stock piping, standard muffler with 3-1 extractor. i was very disappointed and that was when i start studying about all these exhaust stuff
it is a standard setup from every exhaust shop i went for 1.0, where they suggest 1.6" pipe and use sflow to increase backpressure from that 1.6" pipe
i have seen a kelisa 1.0 with stock 1.3"-1.4" piping, change extractor, straight bullet and straight flow muffler and the performance is really satisfying. the exhaust sounds fast and the feeling not like lorry at high gearing speed. definitely way faster than my last 1.6" and sflow setup
if u can have access to ur stock pipe again, i strongly suggest u get them back on, put straight bullet in the middle and custom a 1.5" straight flow muffler at supercircuit for rm350++. if budget does not allow, 2" straight flow is more readily available sometimes at cheaper price, but most importantly get smaller piping
trust me, u will gain much more power in ur driving at all rpm, guaranteed. 1.6" is superb on 1.3 myvi auto
currently engine if not mistaken..should be EJ-VE..