go find at mr google ma ... haha
torque can also be said as pick-up .. the higher the torque the better ur pick-up is .. but higher torque does not mean higher speed ...
4g91 is 1.5 dohc ... 4g15 is 1.5 sohc ...
while stroking it to 1.6 .. u get better torque and i believe with sufficient mod u can achieve higher top speed too ...
coz i don have the experience i cant compare stroked 1.6 to 4g91 ...
one thing i do know is "there is no replacement for displacement" ... means no mod can replace an engine capacity ...
no money la .. seriously no money ... starting work on april .. hopefully after few months can get a new one ...

get a budget laptop .. everyday sit at oldtown, starbucks, mcd, kfc, coffee bean ... mah save some money lo ...