I did 3 simple things without any huge amount of work (actually 2 and im still waiting for the filter and I always use the good petrol anyway)
- change your air filter for the cotton one, or for the cone filter or induction kit
- remap your engines ecu
- always fill your car with quality juice, Vpower from Shell or BPultimate or something like that
But I'm a new here as well so wait for more suggestions as here is a lot of professionals who knows what they are talking about
Well...I replaced the original filter with the Cotton Replacement Filter from Green Filters only due to the lack of space in engine bay to fit the kit or cone filter or come out of the engine bay.
So same filter, but with much better and higher air flow and thats what improves acceleration and possible increases the bhp's
check your booklet and see what fuel it says to use, i dont think the 1.4 needs to use super unleaded so itll be a bit of a waste.
filter and exhaust will help slightly, but you wont get a big difference as its quite a heavy car for the power. your talking you would need to look at headwork be get a really noticable gain.
for the price youd pay for cams, gas flowing the head and a remap to get it all working togeather then you could be looking at around £1500 - 2k. inc labour bear in mind that you would need a custom remap so would be looking at more than a couple of hundred. also remember and think about the insurance gains
considering that selling the 1.4 and buying a 1.9 vrs would be a massive difference after remapping.