Hi and welcome, Jack

This gets asked from time to time on here about the 1.2 8v, and the answer is always no, sadly.
You can always spend money on tuning goodies that might make it sound more powerful, or even make you think it's more powerful.
But to get any noticeable increase costs a fortune.
1.4 would be quicker, cheaper to buy and run than a modified 1.2.
I'd spend the money on decent suspension, brakes and tyres.
If you want to go faster, maybe fast road driving tuition?